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NAUKA I KVAZINAUKA (izvorište inspiracije za mnoga SF dela) => PRIRODNE NAUKE => Topic started by: tomat on 12-09-2012, 12:46:55

Title: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: tomat on 12-09-2012, 12:46:55
Quote
A new experiment shows that measuring a quantum system does not necessarily introduce uncertainty
  By Geoff Brumfiel  (http://www.scientificamerican.com/author.cfm?id=86)


 Contrary to what many students are taught, quantum uncertainty may not always be in the eye of the beholder. A new experiment shows that measuring a quantum system does not necessarily introduce uncertainty. The study overthrows a common classroom explanation of why the quantum world appears so fuzzy, but the fundamental limit to what is knowable at the smallest scales remains unchanged.
 At the foundation of quantum mechanics is the Heisenberg uncertainty principle. Simply put, the principle states that there is a fundamental limit to what one can know about a quantum system. For example, the more precisely one knows a particle's position, the less one can know about its momentum, and vice versa. The limit is expressed as a simple equation that is straightforward to prove mathematically.
 Heisenberg sometimes explained the uncertainty principle as a problem of making measurements. His most well-known thought experiment involved photographing an electron. To take the picture, a scientist might bounce a light particle off the electron's surface. That would reveal its position, but it would also impart energy to the electron, causing it to move. Learning about the electron's position would create uncertainty in its velocity; and the act of measurement would produce the uncertainty needed to satisfy the principle.
 Physics students are still taught this measurement-disturbance version of the uncertainty principle in introductory classes, but it turns out that it's not always true. Aephraim Steinberg of the University of Toronto in Canada and his team have performed measurements on photons (particles of light) and showed that the act of measuring can introduce less uncertainty than is required by Heisenberg’s principle (http://prl.aps.org/abstract/PRL/v109/i10/e100404). The total uncertainty of what can be known about the photon's properties, however, remains above Heisenberg's limit.
 Delicate measurement
 Steinberg's group does not measure position and momentum, but rather two different inter-related properties of a photon: its polarization states. In this case, the polarization along one plane is intrinsically tied to the polarization along the other, and by Heisenberg’s principle, there is a limit to the certainty with which both states can be known.
 The researchers made a ‘weak’ measurement of the photon’s polarization in one plane — not enough to disturb it, but enough to produce a rough sense of its orientation. Next, they measured the polarization in the second plane. Then they made an exact, or 'strong', measurement of the first polarization to see whether it had been disturbed by the second measurement.
 When the researchers did the experiment multiple times, they found that measurement of one polarization did not always disturb the other state as much as the uncertainty principle predicted. In the strongest case, the induced fuzziness was as little as half of what would be predicted by the uncertainty principle.
 Don't get too excited: the uncertainty principle still stands, says Steinberg: “In the end, there's no way you can know [both quantum states] accurately at the same time.” But the experiment shows that the act of measurement isn't always what causes the uncertainty. “If there's already a lot of uncertainty in the system, then there doesn't need to be any noise from the measurement at all,” he says.
 The latest experiment is the second to make a measurement below the uncertainty noise limit. Earlier this year, Yuji Hasegawa, a physicist at the Vienna University of Technology in Austria, measured groups of neutron spins and derived results well below what would be predicted if measurements were inserting all the uncertainty into the system (http://chemport.cas.org/cgi-bin/sdcgi?APP=ftslink&action=reflink&origin=npg&version=1.0&coi=1:CAS:528:DC+C38XnvVahuw==&pissn=0028-0836&md5=460efe720a6aa7f75450feb662e1d2cc).
 But the latest results are the clearest example yet of why Heisenberg’s explanation was incorrect. "This is the most direct experimental test of the Heisenberg measurement-disturbance uncertainty principle," says Howard Wiseman, a theoretical physicist at Griffith University in Brisbane, Australia "Hopefully it will be useful for educating textbook writers so they know that the naive measurement-disturbance relation is wrong."
 Shaking the old measurement-uncertainty explanation may be difficult, however. Even after doing the experiment, Steinberg still included a question about how measurements create uncertainty on a recent homework assignment for his students. "Only as I was grading it did I realize that my homework assignment was wrong," he says. "Now I have to be more careful."
 This article is reproduced with permission from the magazine Nature (http://www.scientificamerican.com/www.nature.com/news). The article was first published (http://www.nature.com/news/quantum-uncertainty-not-all-in-the-measurement-1.11394) on September 11, 2012.
 

http://www.scientificamerican.com/article.cfm?id=common-interpretation-of-heisenbergs-uncertainty-principle-is-proven-false (http://www.scientificamerican.com/article.cfm?id=common-interpretation-of-heisenbergs-uncertainty-principle-is-proven-false)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 13:10:54
http://www.robertlanzabiocentrism.com/is-death-an-illusion-evidence-suggests-death-isnt-the-end/ (http://www.robertlanzabiocentrism.com/is-death-an-illusion-evidence-suggests-death-isnt-the-end/)
Is Death An Illusion? Evidence Suggests Death Isn’t the End (http://www.robertlanzabiocentrism.com/is-death-an-illusion-evidence-suggests-death-isnt-the-end/)

After the death of his old friend, Albert Einstein said “Now Besso has departed from this strange world a little ahead of me. That means nothing. People like us … know that the distinction between past, present and future is only a stubbornly persistent illusion.”

New evidence continues to suggest that Einstein was right – death is an illusion.

Our classical way of thinking is based on the belief that the world has an objective observer-independent existence. But a long list of experiments shows just the opposite. We think life is just the activity of carbon and an admixture of molecules – we live awhile and then rot into the ground.

We believe in death because we’ve been taught we die. Also, of course, because we associate ourselves with our body and we know bodies die. End of story. But biocentrism – a new theory of everything – tells us death may not be the terminal event we think. Amazingly, if you add life and consciousness to the equation, you can explain some of the biggest puzzles of science. For instance, it becomes clear why space and time – and even the properties of matter itself – depend on the observer. It also becomes clear why the laws, forces, and constants of the universe appear to be exquisitely fine-tuned for the existence of life.

Until we recognize the universe in our heads, attempts to understand reality will remain a road to nowhere.

Consider the weather ‘outside’: You see a blue sky, but the cells in your brain could be changed so the sky looks green or red. In fact, with a little genetic engineering we could probably make everything that is red vibrate or make a noise, or even make you want to have sex like with some birds. You think its bright out, but your brain circuits could be changed so it looks dark out. You think it feels hot and humid, but to a tropical frog it would feel cold and dry. This logic applies to virtually everything. Bottom line: What you see could not be present without your consciousness.

In truth, you can’t see anything through the bone that surrounds your brain. Your eyes are not portals to the world. Everything you see and experience right now – even your body – is a whirl of information occurring in your mind. According to biocentrism, space and time aren’t the hard, cold objects we think. Wave your hand through the air – if you take everything away, what’s left? Nothing. The same thing applies for time. Space and time are simply the tools for putting everything together.

Consider the famous two-slit experiment. When scientists watch a particle pass through two slits in a barrier, the particle behaves like a bullet and goes through one slit or the other. But if you don’t watch, it acts like a wave and can go through both slits at the same time. So how can a particle change its behavior depending on whether you watch it or not? The answer is simple – reality is a process that involves your consciousness.

Or consider Heisenberg’s famous uncertainty principle. If there is really a world out there with particles just bouncing around, then we should be able to measure all their properties. But you can’t. For instance, a particle’s exact location and momentum can’t be known at the same time. So why should it matter to a particle what you decide to measure? And how can pairs of entangled particles be instantaneously connected on opposite sides of the galaxy as if space and time don’t exist? Again, the answer is simple: because they’re not just ‘out there’ – space and time are simply tools of our mind.

Death doesn’t exist in a timeless, spaceless world. Immortality doesn’t mean a perpetual existence in time, but resides outside of time altogether.

Our linear way of thinking about time is also inconsistent with another series of recent experiments. In 2002, scientists showed that particles of light “photons” knew – in advance – what their distant twins would do in the future. They tested the communication between pairs of photons. They let one photon finish its journey – it had to decide whether to be either a wave or a particle. Researchers stretched the distance the other photon took to reach its own detector. However, they could add a scrambler to prevent it from collapsing into a particle. Somehow, the first particle knew what the researcher was going to do before it happened – and across distances instantaneously as if there were no space or time between them. They decide not to become particles before their twin even encounters the scrambler. It doesn’t matter how we set up the experiment. Our mind and its knowledge is the only thing that determines how they behave. Experiments consistently confirm these observer-dependent effects.

Bizarre? Consider another experiment that was recently published in the prestigious scientific journal Science (Jacques et al, 315, 966, 2007). Scientists in France shot photons into an apparatus, and showed that what they did could retroactively change something that had already happened in the past. As the photons passed a fork in the apparatus, they had to decide whether to behave like particles or waves when they hit a beam splitter. Later on – well after the photons passed the fork – the experimenter could randomly switch a second beam splitter on and off. It turns out that what the observer decided at that point, determined what the particle actually did at the fork in the past. At that moment, the experimenter chose his past.

Of course, we live in the same world. But critics claim this behavior is limited to the microscopic world. But this ‘two-world’ view (that is, one set of physical laws for small objects, and another for the rest of the universe including us) has no basis in reason and is being challenged in laboratories around the world. A couple years ago, researchers published a paper in Nature (Jost et al, 459, 683, 2009) showing that quantum behavior extends into the everyday realm. Pairs of vibrating ions were coaxed to entangle so their physical properties remained bound together when separated by large distances (“spooky action at a distance,” as Einstein put it). Other experiments with huge molecules called ‘Buckyballs’ also show that quantum reality extends beyond the microscopic world. And in 2005, KHC03 crystals exhibited entanglement ridges one-half inch high, quantum behavior nudging into the ordinary world of human-scale objects.

We generally reject the multiple universes of Star Trek as fiction, but it turns out there is more than a morsel of scientific truth to this popular genre. One well-known aspect of quantum physics is that observations can’t be predicted absolutely. Instead, there is a range of possible observations each with a different probability. One mainstream explanation, the “many-worlds” interpretation, states that each of these possible observations corresponds to a different universe (the ‘multiverse’). There are an infinite number of universes and everything that could possibly happen occurs in some universe. Death does not exist in any real sense in these scenarios. All possible universes exist simultaneously, regardless of what happens in any of them.

Life is an adventure that transcends our ordinary linear way of thinking. When we die, we do so not in the random billiard-ball-matrix but in the inescapable-life-matrix. Life has a non-linear dimensionality – it’s like a perennial flower that returns to bloom in the multiverse.

“The influences of the senses,” said Ralph Waldo Emerson “has in most men overpowered the mind to the degree that the walls of space and time have come to look solid, real and insurmountable; and to speak with levity of these limits in the world is the sign of insanity.”
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 18-09-2012, 13:32:03
Opet neki pesnik izlaže sebe nauci.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 13:34:53
Kako je nauka definisala život?
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 18-09-2012, 13:44:06
Najbolje je početi od vikipedije (http://en.wikipedia.org/wiki/Life).
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 13:47:27
Life (cf. biota) is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not,[1][2] either because such functions have ceased (death), or else because they lack such functions and are classified as inanimate.[3][4] Biology is the science concerned with the study of life.

Znači, dva atoma vodonika i jedan atom kiseonika nemaju potrebu za samoodržanjem? Pa onda bi se sva voda raspala istoga časa.
Takođe, kako bismo znali da postoji molekul vode kad se on ne bi oglašavao?

Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 18-09-2012, 14:05:17
Self-sustaining podrazumeva proaktivnost u potrazi za, jelte, hranom, energijom itd. Nisam siguran kako bi ovo pripisao atomima kiseonika i vodonika.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 14:16:13
To je samo jedan lavirint reči i tumačenja, jer oni zaista ne mogu da odrede tačnu definiciju života. Prilično sam siguran da je uopšte nema, nego se radi o konvenciji.

A šta im ono znači reprodukcija? Ima živih bića koja se uopšte ne reprodukuju.

Drugo, organizmi - tu je mnogo toga propušteno. Sada se zna da je čovečiji organizam sastavljen od 90% DNK koja uopšte nije ljudska, nego živimo u simbiozi s bakterijama.

Nema šanse da NAUKA smisli bolju definiciju života od pesnika.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 18-09-2012, 14:22:56
Pa u korenu svega je uvek konvencija ili aksiom, to nije neka specijalna tajna. Ne možeš definisati stvari preko drugih stvari do beskonačnosti, treba ti prauzrok, jelte, a ako nisi religiozan onda se dogovoriš lepo oko stvari koje se podrazumevaju i gotovo.
 
I koja su to živa bića koja se ne razmnožavaju?
 
I šta zaboga znači da DNK nije ljudska nego da živimo u simbiozi sa bakterijama (recimo onim što nam stanuju u crijevima?)???
 
I valjda je jasno da nauka, filozofija i poezija definišu stvari u različite svrhe, pa tako i na različite načine.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 14:27:17
Pa, radi se o tome da to nisu definicije nego opisi.
Nauka primenjuje "toleranciju", kao kad praviš neku mašinu. Za primitivnu mašinu dovoljna je tolerancija od 1mm a za satni mehanizam ti treba mikrometarska tolerancija.

Ustvari, osnovna osobina života je razmena. Tamo gde nema razmene nema života. A mi vidimo da razmena postoji još na atomskom nivou, a verovatni i dalje od toga.

Ta "razmena" je uslovljena osobinama materije i okruženja.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 14:28:42
Ako bi iz ljudskog organizma odstranio sve bakterije i ono što one čine, čovek bi umro najdalje za 24 sata. Doživeo bi potpuni raspad sistema.

Naš stomak nije organ koji vari hranu, on je organ u kojem bakterije vare hranu.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 18-09-2012, 14:32:41
Pa, radi se o tome da to nisu definicije nego opisi.
Nauka primenjuje "toleranciju", kao kad praviš neku mašinu. Za primitivnu mašinu dovoljna je tolerancija od 1mm a za satni mehanizam ti treba mikrometarska tolerancija.

Ustvari, osnovna osobina života je razmena. Tamo gde nema razmene nema života. A mi vidimo da razmena postoji još na atomskom nivou, a verovatni i dalje od toga.

Ta "razmena" je uslovljena osobinama materije i okruženja.
Pa sad si ti dao definiciju/ opis koja tebi odgovara. Sa onom drugom se barem slaže neki širi krug učenjaka!!! I, pretpostavka je, na njoj grade stvari poput medicine, farmacije itd., sve stvari koje ti proglašavaš prevarantskim biznisima a koje mnogi drugi vide kao načelno korisne i u službi spasavanja/ poboljšanja života. Nepomirljive su te razlike, no, u praktičnom smislu, dakle u smislu da li ću sutra moći da dobijem antibiotik koji će me spasti smrti od infekcije, možda bih prednost radije dao onima drugima.   :lol:
 
Ako bi iz ljudskog organizma odstranio sve bakterije i ono što one čine, čovek bi umro najdalje za 24 sata. Doživeo bi potpuni raspad sistema.

Naš stomak nije organ koji vari hranu, on je organ u kojem bakterije vare hranu.

Ali kakve to veze ima sa sastavom DNK??? Pritom, ni to nije naravno sasvim tačno, naš organizam ima žlezde koje luče enzime koji razgrađuju namirnice i iz njih uzimaju energetske i gradivne materije koje naš organizam koristi. Ne rade baš sav posao bakterije.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 18-09-2012, 14:38:00
Ima živih bića koja se uopšte ne reprodukuju.

To nisam znao. Daj neki link, ako može.

Uzgred, ako pročitaš vikipedijin članak u kompletu videćeš da ima više od jednog načina da se definiše život. Kako god da definišeš život nešto mora da bude izvan definicije, jer bi u suprotnom sve bilo život, a trenutno smatramo da je sve priroda, ali ne i život. Trenutno su virusi izvan definicije života, to jest na granici definicije. Pročitaj članak.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 14:39:16
Pa, radi se o tome da to nisu definicije nego opisi.
Nauka primenjuje "toleranciju", kao kad praviš neku mašinu. Za primitivnu mašinu dovoljna je tolerancija od 1mm a za satni mehanizam ti treba mikrometarska tolerancija.

Ustvari, osnovna osobina života je razmena. Tamo gde nema razmene nema života. A mi vidimo da razmena postoji još na atomskom nivou, a verovatni i dalje od toga.

Ta "razmena" je uslovljena osobinama materije i okruženja.
Pa sad si ti dao definiciju/ opis koja tebi odgovara. Sa onom drugom se barem slaže neki širi krug učenjaka!!! I, pretpostavka je, na njoj grade stvari poput medicine, farmacije itd., sve stvari koje ti proglašavaš prevarantskim biznisima a koje mnogi drugi vide kao načelno korisne i u službi spasavanja/ poboljšanja života. Nepomirljive su te razlike, no, u praktičnom smislu, dakle u smislu da li ću sutra moći da dobijem antibiotik koji će me spasti smrti od infekcije, možda bih prednost radije dao onima drugima.   :lol:
 
Ako bi iz ljudskog organizma odstranio sve bakterije i ono što one čine, čovek bi umro najdalje za 24 sata. Doživeo bi potpuni raspad sistema.

Naš stomak nije organ koji vari hranu, on je organ u kojem bakterije vare hranu.

Ali kakve to veze ima sa sastavom DNK??? Pritom, ni to nije naravno sasvim tačno, naš organizam ima žlezde koje luče enzime koji razgrađuju namirnice i iz njih uzimaju energetske i gradivne materije koje naš organizam koristi. Ne rade baš sav posao bakterije.

Naše žlezde ne luče sve enzime koji su potrebni. Daleko od toga.

Mi smo u simbiozi s bakterijama i njihov DNK ima prevagu u odnosu na čisto ljudski, u tom simbiotskom organizmu kojim mi pogrešno smatramo sebe.
Mnoge stvari koje radimo, činimo jer nam bakterije tako nalažu.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 14:42:29
Ima živih bića koja se uopšte ne reprodukuju.

To nisam znao. Daj neki link, ako može.

Uzgred, ako pročitaš vikipedijin članak u kompletu videćeš da ima više od jednog načina da se definiše život. Kako god da definišeš život nešto mora da bude izvan definicije, jer bi u suprotnom sve bilo život, a trenutno smatramo da je sve priroda, ali ne i život. Trenutno su virusi izvan definicije života, to jest na granici definicije. Pročitaj članak.

Evo, na primer - ja!  8-)

Amebe se ne reprodukuju. One se prosto dele. Ameba na taj način živi milijardu godina. Ako se ne fokusiramo na "individue" onda možemo da vidimo da postoje mnogo složeniji organizmi, čitava biosfera može da se shvati kao jedan organizam.

Sve zavisi od toga kako posmatramo i tumačimo to što vidimo.

Definicija života i nema mnogo smisla, ako ćemo pravo.

Ja zato i kažem da je sva materija živa - ali šta se tu zapravo podrazumeva. Rekao sam ono najprostije do čega sam mogao da dođem dedukcijom - tamo gde ima razmene ima i života. Razmena je život. To je osnovno za svu materiju, za elemente i za sva živa bića koja poznajemo. Ja samo ne želim da mistifikujem, to je sve.

Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 18-09-2012, 14:43:48
Pa, radi se o tome da to nisu definicije nego opisi.
Nauka primenjuje "toleranciju", kao kad praviš neku mašinu. Za primitivnu mašinu dovoljna je tolerancija od 1mm a za satni mehanizam ti treba mikrometarska tolerancija.

Ustvari, osnovna osobina života je razmena. Tamo gde nema razmene nema života. A mi vidimo da razmena postoji još na atomskom nivou, a verovatni i dalje od toga.

Ta "razmena" je uslovljena osobinama materije i okruženja.
Pa sad si ti dao definiciju/ opis koja tebi odgovara. Sa onom drugom se barem slaže neki širi krug učenjaka!!! I, pretpostavka je, na njoj grade stvari poput medicine, farmacije itd., sve stvari koje ti proglašavaš prevarantskim biznisima a koje mnogi drugi vide kao načelno korisne i u službi spasavanja/ poboljšanja života. Nepomirljive su te razlike, no, u praktičnom smislu, dakle u smislu da li ću sutra moći da dobijem antibiotik koji će me spasti smrti od infekcije, možda bih prednost radije dao onima drugima.   :lol:
 
Ako bi iz ljudskog organizma odstranio sve bakterije i ono što one čine, čovek bi umro najdalje za 24 sata. Doživeo bi potpuni raspad sistema.

Naš stomak nije organ koji vari hranu, on je organ u kojem bakterije vare hranu.

Ali kakve to veze ima sa sastavom DNK??? Pritom, ni to nije naravno sasvim tačno, naš organizam ima žlezde koje luče enzime koji razgrađuju namirnice i iz njih uzimaju energetske i gradivne materije koje naš organizam koristi. Ne rade baš sav posao bakterije.

Naše žlezde ne luče sve enzime koji su potrebni. Daleko od toga.

Mi smo u simbiozi s bakterijama i njihov DNK ima prevagu u odnosu na čisto ljudski, u tom simbiotskom organizmu kojim mi pogrešno smatramo sebe.
Mnoge stvari koje radimo, činimo jer nam bakterije tako nalažu.

Pa i ne tvrdim da sve radimo sami, samo velim da ne rade sve bakterije, to je poenta simbioze.
 
No, šta znači da DNK bakterija ima prevagu? Da u kubiku prostora koji zauzima nasumično odabrani deo mog organizma imaš više različitih DNK setova bakterija nego mene? Naravno, kao što u kubiku prostora koji zauzima nasumično odabrani deo mačke imaš više različitih DNK setova buva nego mačke. Ipak mislim da bi bilo previše tvrditi da buve upravljaju mačkom. Tako i mislim da "mnoge" stvari koje radimo jer bakterije tako nalažu nisu tako strašne mnoge stvari.  :lol:  Svakako ne da bismo sad mogli da tvrdimo da nemamo uobičajeno shvaćenu slobodnu volju zbog prisustva bakterija.
 
 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 18-09-2012, 14:46:22
Amebe se ne reprodukuju. One se prosto dele. Ameba na taj način živi milijardu godina. Ako se ne fokusiramo na "individue" onda možemo da vidimo da postoje mnogo složeniji organizmi, čitava biosfera može da se shvati kao jedan organizam.

Sve zavisi od toga kako posmatramo i tumačimo to što vidimo.

Definicija života i nema mnogo smisla, ako ćemo pravo.

Ja zato i kažem da je sva materija živa - ali šta se tu zapravo podrazumeva. Rekao sam ono najprostije do čega sam mogao da dođem dedukcijom - tamo gde ima razmene ima i života. Razmena je život. To je osnovno za svu materiju, za elemente i za sva živa bića koja poznajemo. Ja samo ne želim da mistifikujem, to je sve.



Ali ovo je opet jedno insularno diskutovanje. Amebe se ne reprodukuju već se samo dele? Ali u praktičnom smislu, daj jednoj amebi dovoljno hrane i prostora i posle određenog vremena imaš mnogo ameba. Dakle, reprodukuju se u praktičnom smislu koji se može iskoristiti za dalje teoretisanje o reprodukciji koje će dovesti do teorija i praksi koje omogućuju da imamo reproduktivnu medicinu.

"Razmena je život" ne deluje kao dovoljno precizna osnova za lekara koji treba da odluči je li njegov pacijent mrtav ili još uvek živ.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 14:46:39
Ne misli se na masu DNK nego na raznovrsnost.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 14:47:47
To kod ameba nije reprodukcija nego produkcija jednog te istog genetskog materijala.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 14:50:49
Uostalom, izraz reprodukcija uopšte nije adekvatan.
Kad se proizvode nove jedinke dolazi do ukrštanja genetskog materijala i porod je uvek malo drugačiji od roditelja, tako da nije reč o reprodukciji u smislu da se ponavlja i održava jedno te isto.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 18-09-2012, 14:51:12
Pa ja i pričam o raznovrsnosti DNK a takođe pričam da joj ti oovde sad pridaješ jednu važnost koja nije intuitivno očigledna niti značajna, rekao bih. Takođe, ovo za amebe je meni upravo primer mistifikacije i semantičkog zamagljivanja. Amebe se de fakto reprodukuju - gde je bila jedna sada su dve itd. Dele isti buprint, naravno, pa šta, reprodukcija ne podrazumeva samo seksualno razmnožavanje (sa kombinovanjem gena).
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 18-09-2012, 14:54:31
Aseksualna reprodukcija (http://en.wikipedia.org/wiki/Asexual_reproduction) je i dalje reprodukcija (http://en.wikipedia.org/wiki/Reproduction). Ne možeš ti da daješ svoje definicije koje se razlikuju od postojećih, samo zato što ne znaš ili ne prihvataš postojeću definiciju.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 14:56:51
Nisam video nikakvu preciznu definiciju života na wikipediji. Video sam svašta, samo to ne. To je obična katalogizacija, nema nikakve definicije. I izraz reprodukcija, koji znači razmnožavanje je neadekvatan. Reprodukcija je kada štampaš nešto jednom te istom matricom. Kada se kod svake kopije desi mutacija, a to je pravilo kod razmnožavanja živih bića, onda tu nema nikakve reprodukcije, već nešto samo približno tome, u skladu s odgovarajućom tolerancijom.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 18-09-2012, 15:00:40
Kufer, a da ti nama napišeš storiju o životu jednog kiseonika? Sa uvodom, zapletom i raspletom.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 15:01:48
Kad mi objasniš koliko se puta dnevno razmnožiš  :roll:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 18-09-2012, 15:07:18
To je lako. Razmnožavamo se svaki dan. Kožu, valjda, presvučemo potpuno svake dve nedelje, ako ne sikćemo. Ako sikćemo i češće, a ako oberemo kožu na šiljak može da bude i fatalno. Ako nas ufate. Daj, ne davi više Mehu, ne može na vreme da se virtualno reprodukuje.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Mica Milovanovic on 18-09-2012, 15:14:33
Sto se tice bakterija, jako mi je tesko, ali moram da stanem na kuferovu stranu...
Ja sam svoje rodjene sjebao, verovatno antibioticima, i sada imam puno problema...


U poslednjem broju Economista ima dobar clanak o tome...


[size=78%]http://www.economist.com/node/21560523 (http://www.economist.com/node/21560523)[/size]





Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 18-09-2012, 15:20:27
I ja sam, ako se skupno nazivaju imunitetom. Samo se pravim blesav, da me potpuno ne napuste.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 15:22:38
Bio jednom jedan atom kisika.
Živeo je srećno u srećnoj bračnoj zajednici s dve vodikteljice.
Onda se pojavio sumpor, koji je živeo u nesrećnoj bračnoj zajednici s dva kisika.
Za srećniji brak trebao mu je još jedan kisik.
Utom tuda naiđe i srećni brak dve vodikteljice i jednog sumpora.
Ove dve vodikteljice odmah požele da se presele kod kisika, jer je sumpor od ovoga, malo težeg karaktera i ruke.
Prve dve vodikteljice se utom uplaše i pobegnu, a sumpor-A ugrabi priliku i veže za sebe kisika-A, pa stvori neraskidivu zajednicu s tri kisika.
Dođe tu do prave drame i jurnjave.
Ne lezi vraže, pojavi se još jedan srećni brak, kisika-C i dve vodikteljice.
Sumpor-A predloži ovoj zajednici da se udruže i tako odbrane od viška vodikteljica pretvarajući ih u temperaturu.
Tako je nastala sumporna kiselina i topla geštalt-okolina.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 18-09-2012, 15:27:08
Fali ti provodadžika inače od srećnog braka ništa.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 15:28:08
Ma, da sam Krleža, ja bi napiso Glembajeve od ovoga, al mrzi me...
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 15:32:09
Ovo, o bakterijama je mlogo zanimljivo.
Šta ako imamo potrebu da se međusobno žvalavimo (ljubimo) samo zbog toga da bi se dobavile nove vrste bakterija?
Zvuči realistično, tako mi sto znojavih oktopoda!
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 15:34:04
Sto se tice bakterija, jako mi je tesko, ali moram da stanem na kuferovu stranu...
Ja sam svoje rodjene sjebao, verovatno antibioticima, i sada imam puno problema...


U poslednjem broju Economista ima dobar clanak o tome...


[size=78%]http://www.economist.com/node/21560523 (http://www.economist.com/node/21560523)[/size]




Super članak!
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Mica Milovanovic on 18-09-2012, 15:34:31
ljubljenje??? meni iz svega ovog izgleda kao da mi je jedini spas da jedem (tudja) govna...  :(
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 15:35:54
 :D

Ali, zanimljivo, svi su izgledi da su ti bakterjiski super organizmi - mikrobiomi, nešto kao mozak... U najmanju ruku, kompleksni programi.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 15:39:21
Joj, ovo mora da se proba  :?

Quote
Yogurts are limited in the range of bacteria they can transmit. Another intervention, though, allows entire bacterial ecosystems to be transferred from one gut to another. This is the transplanting of a small amount of faeces. Mark Mellow of the Baptist Medical Centre in Oklahoma City uses such faecal transplants to treat infections of Clostridium difficile, a bug that causes severe diarrhoea and other symptoms, particularly among patients already in hospital.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 18-09-2012, 16:00:44
Ima ovde donatora ko pleve.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 18-09-2012, 16:06:59
Joooj, sad kad nastane borba za resurse  :idea:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 19-09-2012, 01:17:15
Consider the famous two-slit experiment. When scientists watch a particle pass through two slits in a barrier, the particle behaves like a bullet and goes through one slit or the other. But if you don’t watch, it acts like a wave and can go through both slits at the same time. So how can a particle change its behavior depending on whether you watch it or not? The answer is simple – reality is a process that involves your consciousness.

Or consider Heisenberg’s famous uncertainty principle. If there is really a world out there with particles just bouncing around, then we should be able to measure all their properties. But you can’t. For instance, a particle’s exact location and momentum can’t be known at the same time. So why should it matter to a particle what you decide to measure? And how can pairs of entangled particles be instantaneously connected on opposite sides of the galaxy as if space and time don’t exist? Again, the answer is simple: because they’re not just ‘out there’ – space and time are simply tools of our mind.

“The influences of the senses,” said Ralph Waldo Emerson “has in most men overpowered the mind to the degree that the walls of space and time have come to look solid, real and insurmountable; and to speak with levity of these limits in the world is the sign of insanity.”

Oh, ovo je strašno zanimljiv članak. Očekivala sam raspravu o prve dve boldovane rečenice, a onda sam shvatila da se zbog treće o tome ne diskutuje... :!:

Otprilike se i ja slično pitam kada pitam možemo li da se posmatramo van okvira polnog identiteta? Da probijemo nametnute barijere percepcije čula i uloga? Možda je to ravno samoubistvu? To je čak benigno pitanje u odnosu na tvrdnju da su vreme i prostor samo alati našeg uma. Mislim, šta ako mu oduzmemo te alate? Šta bi bilo sa univerzumom? Kako univerzum stvarno izgleda i da li može "stvarno da izgleda"? Ako je u našima umovima, onda smo sve što vidimo, zvezde, sazvežđa, galaksije, svemir, sami smislili, sami smo se okružili time i vidimo samo tri dimenzije (+1 ) koje smo smislili.

Univerzum u umu je zaista ludačka tema. Ja bih sad o njoj, ali se ne bih usudila prva. A verujem i da bih naišla na tišinu... Svačiju, osim lordovu.

Ali navešću da sam nekada davno, u srednjoj školi još, pokušavala da intuitivni osećaj o poreklu svemira dovedem u racionalnu percepciju. Problem je što mi je to poništavalo čulni osećaj i ja više nisam osećala da postojim u uobičajenim granicama. Naime, lord je sada tražio definiciju života, što je vrlo blizu traženja definicije postojanja...
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 19-09-2012, 01:47:50
Јер ми смо само шетња електрона
Из једног у друго стање заблуде...
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 19-09-2012, 01:49:03
Opet neki pesnik izlaže sebe nauci.

Јер ми смо само шетња електрона
Из једног у друго стање заблуде...


 :!:

Eto zašto pesnik treba sebe da izlaže nauci.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 19-09-2012, 01:50:06
Odgovor mora da bude efikasan, a nauka sebi rezerviše vekove do kraja vremena  :roll:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 19-09-2012, 02:27:48
Ima živih bića koja se uopšte ne reprodukuju.

To nisam znao. Daj neki link, ako može.

Evo, na primer - ja!  8)



ahahahahah!  :lol:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 06-10-2012, 08:41:41
Kvantna fizika na kolenima!
 
Quantum measurements leave Schrödinger's cat alive (http://www.newscientist.com/article/dn22336-quantum-measurements-leave-schrodingers-cat-alive.html)
 
Quote

Schrödinger's cat, the enduring icon of quantum mechanics, has been defied. By making constant but weak measurements of a quantum system, physicists have managed to probe a delicate quantum state without destroying it – the equivalent of taking a peek at Schrodinger's metaphorical cat without killing it. The result should make it easier to handle systems such as quantum computers (http://www.newscientist.com/article/mg21128295.200-quantum-computer-chips-pass-key-milestones.html) that exploit the exotic properties of the quantum world.
Quantum objects have the bizarre but useful property of being able to exist in multiple states at once, a phenomenon called superposition. Physicist Erwin Schrödinger illustrated the strange implications of superposition by imagining a cat in a box whose fate depends on a radioactive atom (http://www.newscientist.com/article/mg19426031.400-curiosity-doesnt-have-to-kill-the-quantum-cat.html). Because the atom's decay is governed by quantum mechanics – and so only takes a definite value when it is measured – the cat is, somehow, both dead and alive until the box is opened.
Superposition could, in theory, let quantum computers run calculations in parallel by holding information in quantum bits. Unlike ordinary bits, these qubits don't take a value of 1 or 0, but instead exist as a mixture of the two, only settling on a definite value of 1 or 0 when measured.
But this ability to destroy superpositions simply by peeking at them makes systems that depend on this property fragile. That has been a stumbling block for would-be quantum computer scientists, who need quantum states to keep it together long enough to do calculations.
 Gentle measurement Researchers had suggested it should be possible, in principle, to make measurements that are "gentle" enough not to destroy the superposition (http://www.newscientist.com/article/mg21028104.700-quantum-probes-that-wont-kill-schrodingers-cat.html). The idea was to measure something less direct than whether the bit is a 1 or a 0 – the equivalent of looking at Schrödinger's cat through blurry glasses. This wouldn't allow you to gain a "strong" piece of information – whether the cat was alive or dead – but you might be able to detect other properties.
Now, R. Vijay (http://physics.berkeley.edu/research/siddiqi/people.html) of the University of California, Berkeley, and colleagues have managed to create a working equivalent of those blurry glasses. "We only partially open the box," says Vijay.
The team started with a tiny superconducting circuit commonly used as a qubit in quantum computers, and put it in a superposition by cycling its state between 0 and 1 so that it repeatedly hit all the possible mixtures of states.
Next, the team measured the frequency of this oscillation. This is inherently a weaker measurement than determining whether the bit took on the value of 1 or 0 at any point, so the thought was that it might be possible to do this without forcing the qubit to choose between a 1 or a 0. However, it also introduced a complication.
 Quantum pacemaker Even though the measurement was gentle enough not to destroy the quantum superposition, the measurement did randomly change the oscillation rate. This couldn't be predicted, but the team was able to make the measurement very quickly, allowing the researchers to inject an equal but opposite change into the system that returned the qubit's frequency to the value it would have had if it had not been measured at all.
This feedback is similar to what happens in a pacemaker: if the system drifts too far from the desired state, whether that's a steady heartbeat or a superposition of ones and zeros, you can nudge it back towards where it should be.
Vijay's team was not the first to come up with this idea of using feedback to probe a quantum system, but the limiting factor in the past had been that measurements weak enough to preserve the system gave signals too small to detect and correct, while bigger measurements introduced noise into the system that was too big to control.
 Error correction Vijay and colleagues used a new kind of amplifier that let them turn up the signal without contaminating it. They found that their qubit stayed in its oscillating state for the entire run of the experiment. That was only about a hundredth of a second – but, crucially, it meant that the qubit had survived the measuring process.
"This demonstration shows we are almost there, in terms of being able to implement quantum error controls," Vijay says. Such controls could be used to prolong the superpositions of qubits in quantum computing, he says, by automatically nudging qubits that were about to collapse.
The result is not perfect, points out Howard Wiseman (http://www.ict.griffith.edu.au/wiseman/) of Griffith University in Brisbane, Australia, in an article accompanying the team's paper. "But compared with the no-feedback result of complete unpredictability within several microseconds, the observed stabilization of the qubit's cycling is a big step forward in the feedback control of an individual qubit."
Journal reference: Nature (http://www.nature.com/nature/), DOI: 10.1038/nature11505
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Mica Milovanovic on 06-10-2012, 11:07:43
Naravoučenije: sve radi polagano, u rukavicama, i isplatiće ti se...


Mi Srbi bi radije pobili sve mačke... Meho, naravno, ne bi...
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 08-10-2012, 13:22:55
Kad naučnik kaže "almost there" dođe mi da zaplačem od sreće i ponosa  8-)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 13-10-2012, 09:37:24
I Ajnštajn posrće:
 
Einstein's math may also describe faster-than-light velocities (http://www.csmonitor.com/Science/2012/1010/Einstein-s-math-may-also-describe-faster-than-light-velocities)
 
Quote

Although Einstein's theories suggest nothing can move faster than the speed of light, two scientists have extended his equations to show what would happen if faster-than-light travel were possible.
 
 
Despite an apparent prohibition on such travel by Einstein’s theory of special relativity (http://www.space.com/17661-theory-general-relativity.html), the scientists said the theory actually lends itself easily to a description of velocities that exceed the speed of light.
"We started thinking about it, and we think this is a very natural extension of Einstein's equations," said applied mathematician James Hill (http://www.csmonitor.com/tags/topic/James+Hill), who co-authored the new paper with his University of Adelaide (http://www.csmonitor.com/tags/topic/The+University+of+Adelaide), Australia (http://www.csmonitor.com/tags/topic/Australia), colleague Barry Cox. The paper was published Oct. 3 in the journal Proceedings of the Royal Society A (http://www.csmonitor.com/tags/topic/Proceedings+of+the+Royal+Society+A): Mathematical and Physical Sciences.
  Are you scientifically literate? Take our quiz (http://www.csmonitor.com/Science/2011/1209/Are-you-scientifically-literate-Take-our-quiz) Special relativity, proposed by Albert Einstein (http://www.space.com/15524-albert-einstein.html) in 1905, showed how concepts like speed are all relative: A moving observer will measure the speed of an object to be different than a stationary observer will. Furthermore, relativity revealed the concept of time dilation, which says that the faster you go, the more time seems to slow down. Thus, the crew of a speeding spaceship might perceive their trip to another planet to take two weeks, while people left behind on Earth would observe their passage taking 20 years.
Yet special relativity breaks down if two people's relative velocity, the difference between their respective speeds, approaches the speed of light. Now, Hill and Cox have extended the theory to accommodate an infinite relative velocity. [Top 10 Implications of Faster-Than-Light Neutrinos (http://www.livescience.com/16214-implications-faster-light-neutrinos.html)]
Interestingly, neither the original Einstein equations, nor the new, extended theory can describe massive objects moving at the speed of light (http://www.livescience.com/16248-speed-light-special-relativity-neutrinos.html) itself. Here, both sets of equations break down into mathematical singularities, where physical properties can't be defined.
"The actual business of going through the speed of light is not defined," Hill told LiveScience (http://www.csmonitor.com/tags/topic/LiveScience.com). "The theory we've come up with is simply for velocities greater than the speed of light."
In effect, the singularity divides the universe into two: a world where everything moves slower than the speed of light, and a world where everything moves faster. The laws of physics in these two realms could turn out to be quite different.
In some ways, the hidden world beyond the speed of light looks to be a strange one indeed. Hill and Cox's equations suggest, for example, that as a spaceship traveling at super-light speeds accelerated faster and faster, it would lose more and more mass, until at infinite velocity, its mass became zero.
"It's very suggestive that the whole game is different once you go faster than light," Hill said.
Despite the singularity, Hill is not ready to accept that the speed of light is an insurmountable wall. He compared it to crossing the sound barrier. Before Chuck Yeager (http://www.csmonitor.com/tags/topic/Chuck+Yeager) became the first person to travel faster than the speed of sound (http://www.space.com/16709-breaking-the-sound-barrier.html) in 1947, many experts questioned whether it could be done. Scientists worried that the plane would disintegrate, or the human body wouldn't survive. Neither turned out to be true.
Fears of crossing the light barrier may be similarly unfounded, Hill said.
"I think it's only a matter of time," he said. "Human ingenuity being what it is, it's going to happen, but maybe it will involve a transportation mechanism entirely different from anything presently envisaged."
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 13-10-2012, 09:48:59
Mnogo ga komplikuju. Konstante vremenom postaju nepouzdane. Ha! Ovo je komplikovanije od oligopolije!
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Lord Kufer on 13-10-2012, 10:57:31
A ako se čestica kreće unutar svoje zapremine...???

Ovi plaćenici pojma nemaju. Ja mislim da su previše plaćeni.

"a transportation mechanism entirely different from anything presently envisaged"

Odavno viđeno.  xyxy
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 16-10-2012, 10:11:51
Nije striktno u temi, ali mrzi me da smišljam gde ovo da stavim:
 
  ‘Point of no return’ found (http://news.harvard.edu/gazette/story/2012/10/point-of-no-return-found/) Peering to the edge of a black hole (http://news.harvard.edu/gazette/story/2012/10/point-of-no-return-found/) 
Quote

Using a continent-spanning telescope, an international team of astronomers has peered to the edge of a black hole at the center of a distant galaxy. For the first time, they have measured the black hole’s “point of no return” — the closest distance that matter can approach before being irretrievably pulled into the black hole.
A black hole is a region in space where the pull of gravity is so strong that nothing, not even light, can escape. Its boundary is known as the event horizon.
“Once objects fall through the event horizon, they’re lost forever,” says lead author Shep Doeleman, assistant director at the MIT Haystack Observatory (http://www.haystack.mit.edu/) and research associate at the Harvard-Smithsonian Center for Astrophysics (http://www.cfa.harvard.edu/) (CfA). “It’s an exit door from our universe. You walk through that door, you’re not coming back.”
The team examined the black hole at the center of a giant elliptical galaxy called Messier 87 (M87), which is located about 50 million light-years from Earth. The black hole is 6 billion times more massive than the sun. It’s surrounded by an accretion disk of gas swirling toward the black hole’s maw. Although the black hole is invisible, the accretion disk is hot enough to glow.
“Even though this black hole is far away, it’s so big that its apparent size on the sky is about the same as the black hole at the center of the Milky Way,” says co-author Jonathan Weintroub (https://www.cfa.harvard.edu/~jweintro/) of the CfA. “That makes it an ideal target for study.”
According to Einstein’s theory of general relativity, a black hole’s mass and spin determine how close material can orbit before becoming unstable and falling in toward the event horizon. The team was able to measure this innermost stable orbit and found that it’s only 5.5 times the size of the black hole’s event horizon. This size suggests that the accretion disk is spinning in the same direction as the black hole.
The observations were made by linking together radio telescopes in Hawaii, Arizona, and California to create a virtual telescope called the Event Horizon Telescope (http://www.eventhorizontelescope.org/), or EHT. The EHT is capable of seeing details 2,000 times finer than the Hubble Space Telescope (http://hubblesite.org/).
The team plans to expand its telescope array, adding radio dishes in Chile, Europe, Mexico, Greenland, and the South Pole, in order to obtain even more detailed pictures of black holes in the future.
The work is being published in Science Express (http://www.sciencemag.org/content/early/recent).
 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 22-10-2012, 18:08:29
I Njutn je pao, i to od srbske ruke:
 
Formula tačnija od Njutnove (http://www.politika.rs/rubrike/Drustvo/Formula-tacnija-od-Njutnove.lt.html)
 
Quote

Veljko Vujičić objašnjava kako je ponudio bolje rešenje Zakona o gravitaciji od onog koji je dao čuveni Englez i da su njegove rezultate podržale mnoge svetske institucije
 
 
  Gotovo 15 godina rada i istraživanja bilo je potrebno Veljku Vujičiću, članu Srpske akademije nauka i umetnosti (SANU) i nekadašnjem dekanu Matematičkog fakulteta u Beogradu, da kako je zaključeno na mnogobrojnim međunarodnim simpozijuma, ponudi rešenje Zakona o gravitaciji bolje od onoga koje je 1686. godine dao Isak Njutn. Srpski matematičar, u razgovoru za „Politiku”, otkriva kako se zainteresovao za nebesku mehaniku, na koji način je oborio tvrdnje čuvenog engleskog naučnika i govori kako se tokom svog istraživanja suočavao sa ogovaranjima iako niko od onih koji su to činili nije ponudio održive matematičke dokaze za svoje tvrdnje.
– Moje interesovanje za nebesku mehaniku počelo je još za vreme studiranja, odnosno kada sam na Prirodno-matematičkom fakultetu učio i polagao ispit iz istoimenog predmeta. Magistrirao sam na temu „Kretanje tela promenljive mase po autoparalelama”, a taj rad kasnije je prihvaćen i štampan u Zborniku radova SANU. Ubrzo potom odbranio sam doktorsku disertaciju na temu „Kretanje tela promenljive mase i njegova stabilnost”, a u međuvremenu sam boravio na Katedri za teorijsku mehaniku Matematičkog fakulteta moskovskog Univerziteta „Lomonosov”. Iste godine kada sam doktorirao izabran sam za docenta na beogradskom Prirodno-matematičkom fakultetu. Znanje koje sam stekao tokom svih tih godina dozvoljava mi da kažem da sam već tada bio dobro „zagazio” u oblast nebeske mehanike – govori za „Politiku” profesor Vujičić.
Na pitanje kada i kako je odlučio da se „pozabavi” Njutnovim zakonom, odnosno njegovim menjanjem, profesor veli da je to „malo duža priča”. Priznaje da mu ni na kraj pameti nije bilo da menja najveći zakon prirode.
– Duže od tri stotine godina najistaknutiji filozofi prirode, fizičari i matematičari uvažavali su taj zakon. Nisam mogao ni da pomislim da menjam Zakon o međusobnom dejstvu dva tela u vasioni. Ta izmena „iznikla” je sama po sebi iz moje modifikacije klasične analitičke mehanike. U njoj sam zapazio da Zakon o održanju i promeni energije nije tačan za mehaničke sisteme sa promenljivim vezama. Saopštio sam to na seminaru za mehaniku Matematičkog instituta SANU, a potom i na Svetskom kongresu mehanike, a moje izlaganje objavljeno je u mnogim stranim naučnim časopisima – objašnjava srpski matematičar.
Kako je njegova teorija protivrečila predavanjima, radovima i knjigama njegovih kolega, bilo je, kako kaže, logično da počnu osporavanja.
– U želji da svoje tvrdnje neoborivo dokažem, rešio sam da ih primenim na primeru Njutnovog zakona gravitacije. Posle prvog pokušaja, priznajem, usledilo je razočarenje jer nisam dobio formulu Njutnovog zakona. Tek kada sam tome dodao Kopernikove hipoteze i zakone dobio sam traženu Njutnovu formu. To je značilo da je moja formula opštija i tačnija od one koju je dao čuveni Englez. To je potvrđeno na Trećem nternacionalnom simpozijumu klasične i nebeske mehanike, koji je održan u organizaciji Ruske akademije nauka, njenog kompjuterskog centra, Moskovskog državnog Univerziteta „Lomonosov” – navodi Vujičić.
Na sledećem, Četvrtom internacionalnom simpozijumu, takođe u organizaciji najuglednijih institucija, u naučnom komitetu od desetak imena našlo se i ime našeg sagovornika i njegova formula sile gravitacije.
– Opšte je poznato iz prakse i osnovnih znanja iz mehanike, kao i sporta, da će se predmet, kada ga vučete sa dve suprotne strane, kretati ka jačoj. Stručnije rečeno, predmet će se kretati u smeru veće sile. Slična je situacija i sa Mesecom, koji se kreće oko Zemlje. Kada se Mesec nađe između Sunca i Zemlje, račun pokazuje da je sila, računata po Njutnovoj formuli, približno dva i po puta veća od sile kojom Zemlja dejstvuje na Mesec. To je paradoks. Kada se računa po mojoj formuli, dobija se da je sila Zemlje, koja dejstvuje na Mesec, gotovo četiri puta veća od sile Sunca. Ovaj dokaz je objavljen u jednom od najprestižnijih svetskih matematičkih naučnih časopisa – objasnio je profesor.
Dugogodišnji rad i istraživanja otvorila su srpskom profesoru matematike mnoga vrata: član je Američke akademije za mehaniku, Evropske akademije nauka, Internacionalne akademije nelinearnih nauka...
Ceo svoj život posvetio je matematici. Ni u 83. godini, koliko ima, nije mu teško da pomaže učenicima. Tako će, kaže, biti sve dok ga zdravlje služi.
– Matematika je čudna, uđe u krv i na poseban način obeleži život – kaže na kraju profesor Vujičić.
----------------------------------------------------------------------
Saradnja sa NASOM
S obzirom na naučne kvalifikacije koje ime, Vujičić je pozvan da sarađuje sa američkom svemirskom agencijom NASA. Prilikom posete američkoj agenciji, srpskog profesora je jedan od tamošnjih načelnika pitao ima li „crveni karton”.
– Iznenadio sam se jer je posedovanje „crvenog kartona” značilo da znam neke od najstrože čuvanih tajni. Bio je oduševljen mojom teorijom o gravitaciji koja se razlikovala od one koju je postavio Njutn, a pohvalio je i moje matematičko znanje – kaže Vujačić.
  Miroslava Derikonjić objavljeno: 22.10.2012. 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 17-02-2013, 22:20:08
http://www.robertlanzabiocentrism.com/is-death-an-illusion-evidence-suggests-death-isnt-the-end/ (http://www.robertlanzabiocentrism.com/is-death-an-illusion-evidence-suggests-death-isnt-the-end/)
Is Death An Illusion? Evidence Suggests Death Isn’t the End (http://www.robertlanzabiocentrism.com/is-death-an-illusion-evidence-suggests-death-isnt-the-end/)

Consider the famous two-slit experiment. When scientists watch a particle pass through two slits in a barrier, the particle behaves like a bullet and goes through one slit or the other. But if you don’t watch, it acts like a wave and can go through both slits at the same time. So how can a particle change its behavior depending on whether you watch it or not? The answer is simple – reality is a process that involves your consciousness.

BBC Horizon 2011 What is Reality HDTV (http://www.dailymotion.com/video/xkvoa0)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 17-02-2013, 23:29:26
Lepa emisija, ali se smrt ne spominje ni u kakvom kontekstu, pa ni da je iluzija. Jedino što bi se moglo interpretirati kao "iluzija" je teorija da su fenomeni koji se dešavaju u ovom svemiru zapravo projekcije nečega što se dešava izvan svemira. U tom smislu čitav svemir je projekcija, i stoga iluzija, ali to nema veze specijalno sa smrću.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 17-02-2013, 23:30:44
ta, to je teorija svega. ima veze sa svačime, a najviše sa eksperimentom koji sam citirala.  :)
i najviše sa smrću;)

pa paralelne dimenzije? umreš u ovoj, u drugoj ne.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 17-02-2013, 23:39:42
Ovo je emisija o fizici, a smrt spada u metafiziku. Eksperiment se spominje u emisiji, ali nema spomena o smrti. Nema zaključaka o smrti. Nema primisli o smrti. Nema veze sa smrću. Kad povezuješ smrt i ovu emisiju činiš nonsens, i to me iritira. Molim te zato da staneš.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 18-02-2013, 00:14:15
 :-x

mac, reaguješ iz ega, a danas mi je dosta ljudi koji tako reaguju.

ako nisi u stanju da vidiš vezu koju vidim ja, mislim da bi bilo lepo da prećutiš, a ne da pišeš nadmene poruke i govoriš mi da sam počinila nonsens. isto i ja mogu da kažem za tebe, jer ne vidiš očiglednu vezu (niti si, izgleda, pročitao lordov tekst (koji se bavi istim temama kao dokumentarac, gde je smrt samo povod, način da se čitaoci privuku da pročitaju tekst), niti si shvatio dokumentarac).

pročitao si naslov teksta, odgledao film, pomislio kako se smrt nigde ne pominje i rešio da mi to natrljaš na nos. površno i pomalo bezobrazno, moram da ti kažem.


deo teksta koji nisi pročitao:


Quote
Until we recognize the universe in our heads, attempts to understand reality will remain a road to nowhere.
Consider the weather ‘outside’: You see a blue sky, but the cells in your brain could be changed so the sky looks green or red. In fact, with a little genetic engineering we could probably make everything that is red vibrate or make a noise, or even make you want to have sex like with some birds. You think its bright out, but your brain circuits could be changed so it looks dark out. You think it feels hot and humid, but to a tropical frog it would feel cold and dry. This logic applies to virtually everything. Bottom line: What you see could not be present without your consciousness.
In truth, you can’t see anything through the bone that surrounds your brain. Your eyes are not portals to the world. Everything you see and experience right now – even your body – is a whirl of information occurring in your mind. According to biocentrism, space and time aren’t the hard, cold objects we think. Wave your hand through the air – if you take everything away, what’s left? Nothing. The same thing applies for time. Space and time are simply the tools for putting everything together.
Consider the famous two-slit experiment. When scientists watch a particle pass through two slits in a barrier, the particle behaves like a bullet and goes through one slit or the other. But if you don’t watch, it acts like a wave and can go through both slits at the same time. So how can a particle change its behavior depending on whether you watch it or not? The answer is simple – reality is a process that involves your consciousness.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 18-02-2013, 00:37:31
Da si stavila samo link ne bih ništa rekao, ali postavila i emisiju. Povezala si ih. Na linku nema videa, znači ti si to uradila. Naterala si me da potrošim ceo sat proveravajući kako je moguće da ozbiljni ljudi pričaju o metafizičkom pojmu u emisiji o fizici. Gle čuda, to se nije desilo. Nisam uludo potrošio vreme, dobra je emisija, ali nema veze sa tekstom nekog biologa koja kaže da je u biologiji ključ za teorija svega. Neću bre da ćutim, kad nema logike.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 18-02-2013, 00:56:34
A pogledajmo i šta drugi kažu o dr. Robertu Lanzi:

http://www.rationalape.com/2011/01/no-criticism-in-lanzaland.html (http://www.rationalape.com/2011/01/no-criticism-in-lanzaland.html)
Lanza cenzuriše kritičke komentare na svom blogu. Pročitaj šta je obrisao, jer i ja mislim isto što tu piše.

http://nirmukta.com/2009/12/14/biocentrism-demystified-a-response-to-deepak-chopra-and-robert-lanzas-notion-of-a-conscious-universe/ (http://nirmukta.com/2009/12/14/biocentrism-demystified-a-response-to-deepak-chopra-and-robert-lanzas-notion-of-a-conscious-universe/)
Prilično detaljna analiza celog tog biocentrizma. Lanza pogrešno interpretira fizičke fenomene, kao pravi nju-ejdževac.

http://www.wired.com/wiredscience/2007/03/robert_lanza_do/ (http://www.wired.com/wiredscience/2007/03/robert_lanza_do/)
Novinar Wireda poštuje Lanzu kao biologa, ali kad Lanza počne da iznosi teorije o tome da je realnost konstrukt naše kolektivne mašte, ili šta god, sve što može da izusti je "Dude! What?"

Nije Lanza baš neki autoritet za fiziku.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 18-02-2013, 00:59:51
ozbiljni ljudi pričaju o metafizičkom pojmu u emisiji o fizici.

 :-x :-x :-x

ma daj, mac. lepo sam ti natuknula da pročitaš tekst koji je lord postovao. još sam ti i ceo isečak, koji ima direktne veze sa emisijom, citirala. šta ja imam sa tim što ti ne kapiraš??  :-x


lanzu je postavio lord, a ne ja. ja sam linkovala bbc-jev dokumentarac i pronašla vezu. govori se o (poreklu, prirodi) realnosti i u jednom i u drugom.


i lepo sam ti rekla da je smrt samo način da se privuku čitaoci i zato je lanza tako nazvao tekst. da nisi zaslepljen svojim egom toliko, možda bi i mogao da uočiš trag kritike na lanzin račun.  :roll:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 18-02-2013, 01:14:20
Stalno spominješ taj ego, ne znam otkud to. Ja tebi nikad nisam delio epitete, jer to je za mene balast u komunikaciji.

Sad više ne znam, da li ti kritikuješ ili podržavaš teoriju biocentrizma Roberta Lanze? Teraš me da čitam teoriju svega od biologa, kao da ga podržavaš, a ovamo pričaš o tragovima kritike. Na kojoj si ti poziciji?
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 18-02-2013, 01:36:53
i meni je optužba za nonsens balast u komunikaciji. šta je to ako nije etiketa?

prepotentnost u komunikaciji, takođe.

ne pravi se nevinašce, mac.


ni tekst nema direktne veze sa naslovom.

i, na kraju, moja pozicija u celoj priči je da nije moja krivica što ti ne kapiraš.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 24-02-2013, 14:03:07
Bio sam malo zaludan, pa sam našao u emisiji deo koji se tiče našeg eksperimenta. Deo počinje od 17:45 (http://www.dailymotion.com/video/xkvoa0_bbc-horizon-2011-what-is-reality-hdtv_tech&start=1072). Prvo ide opis i objašnjenje. Imamo dva proreza i pojedinačne fotone, i čovek bi očekivao dve trake svetlosti na ploči, ali nisu dve nego su tri (narator kasnije kaže "multiple stripes", ali u svakom slučaju nisu dve). U emisiji su predstavili kao da je bog zna kako začuđujuće, i sam fizičar se čudi zbog tri trake. To se oni čude zbog laika, i onih koji ne znaju ništa o kvantnoj fizici. To će postati jasno kad fizičar da svoj poslednji komentar. Ali, sad idemo dalje.

Sad stavljamo detektore pre proreza. To počinje od 21:30. Narator objašnjava da kad staviš detektore onda su dve trake, kad ukloniš detektore onda je više traka, i primećuje "Rather astonishingly it seems that we can change the way the reality behaves just by looking at it". Da li su ljudi posmatrali foton? Ne, detektor je posmatrao. Da li ljudi uopšte mogu da vide foton? Ne, čitava aparatura je dobro skrivena od dnevne svetlosti i ljudskih pogleda. I ne samo to, nego čak nije ni fizičar napravio taj komentar nego narator. Ali, sad idemo dalje.

Šta kaže Nemac, fizičar? Prvo kaže da ne znamo šta se tačno dešava na putanji fotona, "We cannot describe that with our everyday language". Ono što je prećutano je da možemo opisati jezikom kvantne fizike (videti sledeći pasus). Zatim je prepričao raspravu između Ajnštajna i Bora o tome kako je nemoguće dokazati da Mesec postoji ili ne postoji kad ga niko ne gleda. Ali nije spomenuo oči, jer fizičari ne rade s očima nego s idejama i aparaturama. Kako treba interpretirati to "gledanje Meseca"? Pa, ako ostatak svemira nema informaciju o Mesecu, ni preko fotona (elektro magnetne sile), ni preko gravitacione sile, ni preko ičega drugog što fizičari uzimaju u obzir (a to je bukvalno sve), i time je Mesec potpuno de fakto izolovan od ostatka svemira, onda da li Mesec postoji? Takav uslov je udaljen od pukog posmatranja Meseca ljudskim očima, kao nebo od zemlje.

Šta dalje kaže fizičar? Ono što sam i ja pričao, samo treba razumeti. "Quantum physics is an exiting theory because it is extremely precise, it is mathematically beautiful and it describes everything. It just doesn't make sense". Fizičar je upravo rekao da kvantna teorija objašnjava navodnu misteriju fotona i proreza. "It describes everything". A onda je i rekao da je objašnjenje toliko laicima neobično, da nema smisla. Ali nema smisla samo laicima. Kvantnim fizičarima ima smisla.

D... Ti si rekla da fizičar kaže isto što i Robert Lanza. To naprosto nije istina. Objasni se sad.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Stipan on 24-02-2013, 14:17:35
(https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-ash3/539639_223006361174142_2031026133_n.jpg)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 24-02-2013, 14:26:17
Pa, ako ostatak svemira nema informaciju o Mesecu, ni preko fotona (elektro magnetne sile), ni preko gravitacione sile, ni preko ičega drugog što fizičari uzimaju u obzir (a to je bukvalno sve), i time je Mesec potpuno de fakto izolovan od ostatka svemira, onda da li Mesec postoji? Takav uslov je udaljen od pukog posmatranja Meseca ljudskim očima, kao nebo od zemlje.

Šta dalje kaže fizičar? Ono što sam i ja pričao, samo treba razumeti. "Quantum physics is an exiting theory because it is extremely precise, it is mathematically beautiful and it describes everything. It just doesn't make sense". Fizičar je upravo rekao da kvantna teorija objašnjava navodnu misteriju fotona i proreza. "It describes everything". A onda je i rekao da je objašnjenje toliko laicima neobično, da nema smisla. Ali nema smisla samo laicima. Kvantnim fizičarima ima smisla.

D... Ti si rekla da fizičar kaže isto što i Robert Lanza. To naprosto nije istina. Objasni se sad.

I ovaj fizičar dekonstruiše realnost na isti način kao i Lanza (i ne samo on). Ja sam u toj dekonstrukciji videla vezu. Postojanje meseca zavisi od toga da li ga gledamo. The Moon is not there when nobody is looking.
To je isto što i kada gledamo u foton - ponaša se drugačije, nego kada ne gledamo.

Sada ja ne umem da ti objasnim bolje, moraćeš da se potrudiš još.

Što se tiče "smislenosti" kvantne fizike, to si ti protumačio da ima smisla fizičarima, ja ne mislim da je fizičar to rekao. Mislim da je rekao da nema smisla kada treba da objasni pojave van polja na kojima zakoni kvantne fizike važe. Odnosno, nekada zakoni važe, a nekada ne (kao i u slučaju fotona). Zato nema smisla. A ne - nema smisla laicima. Nisu svi laici toliko glupi, niti su (svi) fizičari superiorno inteligentni vanzemaljci, pa da samo oni razumeju. To ti je, nekako, vrlo smešan zaključak- Laici ne razumeju, a fizičari da, dakle D. ti i ja ne razumemo, ali to ne znači da ja nisam u pravu.  :lol:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 24-02-2013, 14:31:28
Pa ne mogu oni u deset minuta da objasne te kvantne zakone, za to moraš u škole da ideš. I naravno, kvantni zakoni upravo važe u slučaju fotona, to jest važe svuda i uvek, ali su u slučaju fotona najuočljiviji. Lepo je fizičar rekao "it describes everything", i tu ja nemam više ništa ni da dodam ni da oduzmem. Ko sluša razumeće.

A vidim i dalje stojiš na uverenju da je ljudsko oko to koje uobličuje svemir. I posle svega napisanog. Pa dobro, bar će drugi moći da donesu svoj sud.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 24-02-2013, 14:33:34
"it describes everything"

 xrofl

ma daj, mac...  :( ti veruješ da je u univerzumu sve objašnjeno? pa, kako sad da raspravljam sa tobom?
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 24-02-2013, 14:36:36
A vidim i dalje stojiš na uverenju da je ljudsko oko to koje uobličuje svemir.

Po 100. put. Interpretirala sam tekst i dokumentarac. Ti ih tumačiš potpuno drugačije. Da, i tekst i dokumentarac pričaju o dekonstrulciji realnosti, tako da ona zavisi od ljudske svesti. Ja to ne tvrdim, ja to ne mogu da znam. Ja sam samo opisala tekst i dokumentarac, jer si me ti na to naterao. Nisi video vezu koju sam ja videla, pa sam ti pojasnila vezu. To je samo još jedna teorija "svega".  :lol:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 24-02-2013, 15:10:18
"it describes everything"

 xrofl

ma daj, mac...  :( ti veruješ da je u univerzumu sve objašnjeno? pa, kako sad da raspravljam sa tobom?

Zar se it describes everything ne odnosi na partikularni eksperiment i njegove nalaze? Ne na život, univerzum i sve ostalo.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 24-02-2013, 15:22:36
Ma, Meho, pusti Maca. Valjda će isplivati. Ako ne ispliva, ja ću ga udaviti.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 24-02-2013, 15:30:36

Zar se it describes everything ne odnosi na partikularni eksperiment i njegove nalaze? Ne na život, univerzum i sve ostalo.

Pitajmo to mac-a. Tekst i dokumentarac objašnjavaju realnost. Dakle, vrlo približno objašnjenju univerzuma i svega ostalog.

Nije fer da mi se bilo ko nadmeno obraća, kada me ne razume. Ili ne razume tekst i dokumentarac i ono o čemu govore. Zato je cela frka i nastala.

Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: tomat on 24-02-2013, 16:55:27
Tekst i dokumentarac objašnjavaju realnost. Dakle, vrlo približno objašnjenju univerzuma i svega ostalog.

dokumentarac sam gledao pre nekog vremena (pre nego si ga ti linkovala ovde), a tekst (pretpostavljam da misliš na tekst koji je Lord Kufer postavio) sam ponovo pročitao, i u tekstu ne vidim ni jedan deo koji "objašnjava" realnost. ono pitanje da li je nebo crveno ili plavo mi deluje suludo, čovek može da ga vidi kao crveno i plavo, ali to je samo percepcija realnosti, ne znam šta je time hteo da dokaže. takođe nije jasno na šta misli kada kaže "watch". da li misli na čulno posmatranje, ili naučno posmatranje koje može da uključuje i neke detektore, merne isntrumente i slično?

nisam ranije čuo za Lanzu, pa sam probao da se informišem (ne previše detaljno, moram priznati, ali i ovo što sam pronašao može biti dovoljno). njegove ideje fizičari (pa i medicinari) uglavnom kritikuju. najčešća zamerka je da njegove ideje zanemaruju napretke ostvarene u modernoj fizici, kao i da biocentrizam ne može da obezbedi predviđanja koja su proverljiva. te ideje vide kao neprecizne metafore, dok neki smatraju da predstavljaju interesantnu folozofiju (opet, tu se onda neki filozofi bune jer misle da biocentrizan ne zadovoljava kriterijume neophodne da bi se nešto proglasilo filozofskom teorijom). podršku mu pružaju nju ejdž gurui, koji kažu da je biocentrizam u skladu sa drevnim mudrostima.

ako me sećanje ne vara, ni dokumentarac ne "objašnjava" realnost, već samo iznosi neke ideje i potencijalna objašnjenja. mislim, to je debelo otvorena tema, i bilo bi vrhunsko dostignuće kada bi dokumentarni film uspeo sve to da objasni.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 24-02-2013, 18:13:12
Ja sam razumeo da si u emisiji pronašla argument u korist biocentrizma. Da li sam to pogrešno razumeo? Ako sam to dobro razumeo onda sam tebe razumeo, i nisi u pravu kad kažeš da te ne razumem. Sad smo trenutno u fazi da ti niti tvrdiš da ljudska svest definiše svemir, niti tvrdiš da ne definiše, ali ono što sigurno znaš je da Bor to tvrdi, citirajući anegdotu sa Mesecom. Bor nije rekao to što ti misliš da je rekao. U rečniku kvantnih fizičara posmatranje nije isto što i u rečniku laika. U rečniku kvantnih fizičara kad god dve čestice utiču jedna na drugu one jedna drugu posmatraju, i u tom smislu svemir sve vreme posmatra sam sebe. Problem je što nigde na internetu ne mogu da pronađem objašnjenje "posmatranja".

Zato predlažem da formulišemo pitanje i postavimo ga na physics.stackexchange.com . Sajt postoji upravo da bi ljudi dobili odgovore na takva pitanja. Ovo je pitanje koje bih ja postavio:

In the debate between Albert Einstein and Niels Bohr this question arose: "Do you really think the moon isn't there if you aren't looking at it?". What is the nature of process of "looking at the moon"? What is the nature of observation? Are human conscious and human eyes required to observe the moon? Is human required for the moon to be observed? When the moon is not observed?

Da li se slažeš da bi dobar odgovor na ova pitanja potvrdio ili opovrgao vezu između biocentrizma i Mesečeve anegdote, a time i vezu između biocentrizma i emisije?
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Джон Рейнольдс on 24-02-2013, 18:23:18
Postojanje meseca zavisi od toga da li ga gledamo. The Moon is not there when nobody is looking.

Постоји ли твој мозак кад га нико не гледа? Било који унутрашњи орган?
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Stipan on 24-02-2013, 18:49:20
Baš i nije fer udarati po nekome ko nije u stanju da se brani, zar ne?
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Джон Рейнольдс on 24-02-2013, 18:51:10
Добила је бан на само 24 часа, одговориће кад се врати. И нема никаквог ударања. Моје питање је сасвим валидно у контексту ове приче, а и Маково.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 06-03-2013, 09:52:55
Idemo dalje sa rušenjem Hajzenberga:
 
Getting Around the Uncertainty Principle: Physicists Make First Direct Measurements of Polarization States of Light (http://www.sciencedaily.com/releases/2013/03/130303154958.htm)
 
 
Quote

Mar. 3, 2013 — Researchers at the University of Rochester and the University of Ottawa have applied a recently developed technique to directly measure for the first time the polarization states of light. Their work both overcomes some important challenges of Heisenberg's famous Uncertainty Principle and also is applicable to qubits, the building blocks of quantum information theory.
 
They report their results in a paper published this week in Nature Photonics.
The direct measurement technique was first developed in 2011 by scientists at the National Research Council, Canada, to measure the wavefunction -- a way of determining the state of a quantum system.
Such direct measurements of the wavefunction had long seemed impossible because of a key tenet of the uncertainty principle -- the idea that certain properties of a quantum system could be known only poorly if certain other related properties were known with precision. The ability to make these measurements directly challenges the idea that full understanding of a quantum system could never come from direct observation.
The Rochester/Ottawa researchers, led by Robert Boyd, who has appointments at both universities, measured the polarization states of light -- the directions in which the electric and magnetic fields of the light oscillate. Their key result, like that of the team that pioneered direct measurement, is that it is possible to measure key related variables, known as "conjugate" variables, of a quantum particle or state directly. The polarization states of light can be used to encode information, which is why they can be the basis of qubits in quantum information applications.
"The ability to perform direct measurement of the quantum wavefunction has important future implications for quantum information science," explained Boyd, Canada Excellence Research Chair in Quantum Nonlinear Optics at the University of Ottawa and Professor of Optics and Physics at the University of Rochester. "Ongoing work in our group involves applying this technique to other systems, for example, measuring the form of a "mixed" (as opposed to a pure) quantum state."
Previously, a technique called quantum tomography has allowed researchers to measure the information contained in these quantum states, but only indirectly. Quantum tomography requires intensive post-processing of the data, and this is a time-consuming process that is not required in the direct measurement technique. Thus, in principle, the new technique provides the same information as quantum tomography but in significantly less time.
"The key to characterizing any quantum system is gathering information about conjugate variables," said co-author Jonathan Leach, who is now a lecturer at Heriot-Watt University, UK. "The reason it wasn't thought possible to measure two conjugate variables directly was because measuring one would destroy the wavefunction before the other one could be measured."
The direct measurement technique employs a "trick" to measure the first property in such a way that the system is not disturbed significantly and information about the second property can still be obtained. This careful measurement relies on the "weak measurement" of the first property followed by a "strong measurement" of the second property.
First described 25 years ago, weak measurement requires that the coupling between the system and what is used to measure it be, as its name suggests, "weak," which means that the system is barely disturbed in the measurement process. The downside of this type of measurement is that a single measurement only provides a small amount of information, and to get an accurate readout, the process has to be repeated multiple times and the average taken.
Boyd and his colleagues used the position and momentum of the light as the indicator of the polarization state. To couple the polarization to the spatial degree of freedom they used birefringent crystals: when light goes through such a crystal, there is a spatial separation introduced for different polarizations. For example, if light is made of a combination of horizontally and vertically polarized component, the positions of the individual components will spread out when it goes through the crystal according to its polarization. The thickness of the crystal can control the strength of the measurement, weak or strong, and determine the degree of separation, correspondingly small or large.
In this experiment, Boyd and his colleagues passed polarized light through two crystals of differing thicknesses: the first, a very thin crystal that "weakly" measures the horizontal and vertical polarization state; the second, a much thicker crystal that "strongly" measures the diagonal and anti-diagonal polarization state. As the first measurement was performed weakly, the system is not significantly disturbed, and therefore, information gained from the second measurement was still valid. This process is repeated several times to build up accurate statistics. Putting all of this together gives a full, direct characterization of the polarization states of the light.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 06-03-2013, 10:17:48
Sad ispade da oni ne posmatraju istu česticu u više merenja. Možda sam nešto propustio, ali rekao bih da Hajzenbergov princip nije narušen ako u različitim merenjima mere različite čestice da bi dobili prosek.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 06-03-2013, 10:29:34
Da, pa koliko ja umem da se razaberem, zaista ne mere istu česticu, nego isti talas i to tako da talasna funkcija od prvog merenja ostane netaknuta/ nekolabirana... Tu su negde...
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 06-03-2013, 10:40:23
Što se, bre, mučite? Lepše je - neizvesno. xrofl
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 02-08-2013, 10:24:32
Nothing to See Here: Demoting the Uncertainty Principle (http://opinionator.blogs.nytimes.com/2013/07/21/nothing-to-see-here-demoting-the-uncertainty-principle/?_r=0)

Quote
“You’ve observed the robbers. They know it. That will change their actions,” says Charlie Eppes, the math savant who helps detectives on television’s “Numbers.” Eppes claims that this insight follows from quantum physics, in particular, Werner Heisenberg’s infamous “uncertainty principle.” Not all mischaracterizations of Heisenberg’s principle are as innocent as Eppes’s. The film “What the Bleep Do We Know!?” uses it to justify many articles of faith in New Age philosophy. Asserting that observing water molecules changes their molecular structure, the film reasons that since we are 90 percent water, physics therefore tells us that we can fundamentally change our nature via mental energy. Fundamentally inaccurate uses of the principle are also common in the academy, especially among social theorists, who often argue that it undermines science’s claims to objectivity and completeness. As Jim Holt has written, “No scientific idea from the last century is more fetishized, abused and misunderstood — by the vulgar and the learned alike — than Heisenberg’s uncertainty principle.”
Why exactly is the uncertainty principle so misused? No doubt our sensationalist and mystery-mongering culture is partly responsible. But much of the blame should be reserved for the founders of quantum physics themselves, Heisenberg and Niels Bohr. Though neither physicist would have sanctioned the above nonsense, it’s easy to imagine how such misapprehensions arise, given the things they do say about the principle, and especially the central place they both give to the concept of measurement.



Heisenberg vividly explained uncertainty with the example of taking a picture of an electron. To photograph an electron’s position – its location in space – one needs to reflect light off the particle. But bouncing light off an electron imparts energy to it, causing it to move, thereby making uncertain its velocity. To know velocity with certainty would then require another measurement. And so on. While this “disturbance” picture of measurement is intuitive – and no doubt what inspires the common understanding exemplified in “Numbers” – it leaves the reason for uncertainty mysterious. Measurement always disturbs, yet that didn’t stop classical physicists from in principle knowing position and velocity simultaneously.
For this reason Heisenberg supplemented this picture with a theory in which measurement figures prominently. It’s not simply that we can’t simultaneously measure definite values of position and momentum, he thought. It’s that before measurement those values don’t simultaneously exist. The act of observation brings into existence the properties of the world. Here we find the seeds of the claims made by some social theorists and found in “What the Bleep Do We Know!?” If reality depends on interaction with us, it’s natural to suppose that objectivity is undermined and that we, from the outside, make reality, possibly with some kind of mental energy.



Bohr, for his part, explained uncertainty by pointing out that answering certain questions necessitates not answering others. To measure position, we need a stationary measuring object, like a fixed photographic plate. This plate defines a fixed frame of reference. To measure velocity, by contrast, we need an apparatus that allows for some recoil, and hence moveable parts. This experiment requires a movable frame. Testing one therefore means not testing the other. Here we find inspiration for the idea that the principle shows that science can never answer everything.
¶But as interpretations of the principle, both views are baffling, most of all for the undue weight they give to the idea of measurement.
¶To understand what the uncertainty principle actually says, one needs to understand the broader physical theory in which it figures: quantum mechanics. It’s a complex theory, but its basic structure is simple. It represents physical systems – particles, cats, planets – with abstract quantum states. These quantum states provide the chances for various things happening. Think of quantum mechanics as an oddsmaker. You consult the theory, and it provides the odds of something definite happening. You ask, “Oddsmaker, what are the chances of finding this particle’s location in this interval?” and the equations of the theory answer, “25 percent.” Or “Oddsmaker, what are the chances of finding the particle’s energy in this range?” and they answer, “50 percent.”
¶The quantum oddsmaker can answer these questions for every conceivable property of the system. Sometimes it really narrows down what might happen: for instance, “There is a 100 percent chance the particle is located here, and zero percent chance elsewhere.” Other times it spreads out its chances to varying degrees: “There is a 1 percent chance the particle is located here, a 2 percent change it is located there, a 1 percent chance over there and so on.”
¶The uncertainty principle simply says that for some pairs of questions to the oddsmaker, the answers may be interrelated. Famously, the answer to the question of a particle’s position is constrained by the answer to the question of its velocity, and vice versa. In particular, if we have a huge ensemble of systems each prepared in the same quantum state, the more the position is narrowed down, the less the velocity is, and vice versa. In other words, the oddsmaker is stingy: it won’t give us good odds on both position and velocity at once.
¶Note that nowhere in my explanation of the principle did I mention anything about measurement. The principle is about quantum states and what odds follow from these states. To add the notion of measurement is to import extra content. And as the great physicist John S. Bell has said, formulations of quantum mechanics invoking measurement as basic are “unprofessionally vague and ambiguous.”
¶After all, why is a concept as fuzzy as measurement part of a fundamental theory? Interactions abound. What qualifies some as measurements? Inasmuch as disturbance is related to uncertainty, it’s hardly surprising that observing something causes it to change, since one observes by interacting. But a clear and complete physical theory should describe the physical interaction in its own terms.
¶Today there are several interpretations of quantum mechanics that do just that. Each gives its own account of interactions, and hence gives different meaning to the principle.
¶Consider the theory invented by the physicists Louis de Broglie and David Bohm, commonly referred to as the de Broglie-Bohm view. It supplements the quantum state with particles that always have determinate positions, contra Heisenberg. Measurement interactions are simply a species of particle interaction. Uncertainty still exists. The laws of motion of this theory imply that one can’t know everything, for example, that no perfectly accurate measurement of the particle’s velocity exists.
¶This is still surprising and nonclassical, yes, but the limitation to our knowledge is only temporary. It’s perfectly compatible with the uncertainty principle as it functions in this theory that I measure position exactly and then later calculate the system’s velocity exactly. But the bigger point is that because of the underlying physical picture, we here know exactly why uncertainty exists.



Other interpretations exist. For example, there are the “collapse” theories associated with the physicist Giancarlo Ghirardi. In these theories the quantum state abruptly changes its development (“collapses”) when big things interact with small things. Here fields of mass interact with one another. And in the “many worlds” picture of the physicist Hugh Everett III, all the possibilities given odds by the oddsmaker come to fruition, but in parallel worlds. Here the abstract quantum state is regarded as physical, and interactions are connections that develop between different bits of this strange reality.
¶All of these interpretations have their pros and cons, but in none do observers play a fundamental role. You and I are big clumps or aspects of the basic stuff. Measurement is simply a type of interaction among those types of stuff, no different than a basketball’s redirection when bounced off a patch of uneven gym floor.
¶Once one removes the “unprofessional vagueness” surrounding the notion of measurement in quantum physics, the principle falls out as a clear corollary of quantum physics. Weirdness remains, of course. The stingy quantum oddsmaker is genuinely odd. But all the truly wild claims – that observers are metaphysically important, that objectivity is impossible, that we posses a special kind of mental energy – are the result of foggy interpretations made even less sharp by those wanting to validate their pet metaphysical claims with quantum physics.
¶To prevent future temptation to misuse, I urge that we demote the uncertainty principle. If Pluto can be reclassified as a dwarf planet, then surely we can do something similar here. Going forward, let’s agree to call the uncertainty principle the “uncertainty relations” or even the less provocative “quantum standard deviation constraints.” Not many people outside of a lab are likely to invoke a principle with a name like this.
¶And that’s probably a good thing.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 27-09-2013, 09:53:45
Mislim da je ovaj topik prikladno mesto pošto smo na njemu imali više primera skepticističkog odnosa prema naučnim "istinama" a, reklo bi se bez pravog shvatanja šta u nauci "istina" podrazumeva i sa jednim impliciranim sentimentom da komentar laika koji se interesuje za temu i komentar stručnjaka koji provodi godine u temi nekako imaju istu težinu.

Naime, Popular Science, magazin koji postoji skoro vek i po je odlučio da ukine komentarisanje tekstova na svom sajtu. Pre neki dan sam na topik "Mehmete, reaguj" okačio zanimljivu studiju evolucije Internet komentara u kojoj se diskutuje o tome je li trenutni način komentarisanja (to da su komentari ispod glavnog teksta i da je time svako ko komentariše po difoltu postavljen u inferioran odnos u poređenju sa samim autorom) zapravo uzrok toga da komentari budu nabijeni gnevom i resantimanom (mada se i tu priznaje da je autor često neko ko je posvetio mnogo vremena i truda materiji a komentatori kako koji) i da li bi zamenjivanje komentara koji idu hronološki ispod teksta, anotacijama u samom tekstu koje bi se odnosile na partikularne delove teksta bilo bolje jer bi ljude nateralo da se bave konkretnim stvarima itd.

E, sad, Popular Science, videćete dole, veli da im je preko kurca ne samo čišćenja sekcije za komentare od spambotova i trolova, nego i od stalnog dotoka lupetanja ljudi koji misle da o naučnim temama mogu da pričaju bez prolaska kroz materiju, bez usvajanja znanja i disciplinovanog kritičkog odnosa prema istima, dakle ljudi koji misle da je skepticizam isto što i nasumičnost.

I, dok ja razumem njihov sentiment, mislim da je malo i opasno da magazin koji slavi nauku, naizgled beži od kritičkog diskursa i diskutovanja koje bi moglo u pitanje dovesti njegove tvrdnje. Mislim da bi ulaganje više napora u moderisanje bilo bolje rešenje ali nije da sam ja knjigovođa Popular Sciencea... Da jesam, verovatno bih sugerisao da se pokuša sa uvođenjem kolektivnog moderiranja po uzoru na Slashdot, ali eto...

Why We're Shutting Off Our Comments  (http://www.popsci.com/science/article/2013-09/why-were-shutting-our-comments)



Quote
Starting today, PopularScience.com will no longer accept comments on new articles. Here's why.

Comments can be bad for science. That's why, here at PopularScience.com, we're shutting them off.
It wasn't a decision we made lightly. As the news arm of a 141-year-old science and technology magazine, we are as committed to fostering lively, intellectual debate as we are to spreading the word of science far and wide. The problem is when trolls and spambots overwhelm the former, diminishing (http://www.popsci.com/science/article/2013-06/president-obama-finally-does-something-about-climate-change#comments) our ability (http://www.popsci.com/science/article/2013-06/first-its-kind-study-tracks-women-who-couldnt-get-abortions-when-they-wanted-them#comments) to do the latter.
That is not to suggest that we are the only website in the world that attracts vexing commenters. Far from it (http://www.motherjones.com/environment/2013/05/video-meet-climate-trolls). Nor is it to suggest that all, or even close to all, of our commenters are shrill, boorish specimens of the lower internet phyla. We have many delightful, thought-provoking commenters (http://www.popsci.com/science/article/2013-08/argument-against-algebra#comment-175743).
But even a fractious minority wields enough power to skew a reader's perception of a story, recent research suggests. In one study led by University of Wisconsin-Madison professor Dominique Brossard, 1,183 Americans read a fake blog post on nanotechnology and revealed in survey questions how they felt about the subject (are they wary of the benefits or supportive?). Then, through a randomly assigned condition, they read either epithet- and insult-laden comments ("If you don't see the benefits of using nanotechnology in these kinds of products, you're an idiot" ) or civil comments. The results, as Brossard and coauthor Dietram A. Scheufele wrote (http://www.nytimes.com/2013/03/03/opinion/sunday/this-story-stinks.html?_r=0) in a New York Times op-ed: Uncivil comments not only polarized readers, but they often changed a participant's interpretation of the news story itself.  In the civil group, those who initially did or did not support the technology — whom we identified with preliminary survey questions — continued to feel the same way after reading the comments. Those exposed to rude comments, however, ended up with a much more polarized understanding of the risks connected with the technology.  Simply including an ad hominem attack in a reader comment was enough to make study participants think the downside of the reported technology was greater than they'd previously thought. Another, similarly designed study found that just firmly worded (but not uncivil) disagreements between commenters impacted readers' perception of science.
If you carry out those results to their logical end--commenters shape public opinion; public opinion shapes public policy; public policy shapes how and whether and what research gets funded--you start to see why we feel compelled to hit the "off" switch.


A politically motivated, decades-long war on expertise has eroded the popular consensus (http://www.nytimes.com/2013/08/22/opinion/welcome-to-the-age-of-denial.html) on a wide variety of scientifically validated topics. Everything, from evolution to the origins of climate change, is mistakenly up for grabs again. Scientific certainty is just another thing for two people to "debate" on television. And because comments sections tend to be a grotesque reflection of the media culture surrounding them, the cynical work of undermining bedrock scientific doctrine is now being done beneath our own stories, within a website devoted to championing science.
There are plenty of other ways to talk back to us, and to each other: through Twitter, Facebook, Google+, Pinterest, livechats, email, and more. We also plan to open the comments section on select articles that lend themselves to vigorous and intelligent discussion. We hope you'll chime in with your brightest thoughts. Don't do it for us. Do it for science.
Suzanne LaBarre is the online content director of Popular Science. Email suzanne.labarre at popsci dot com.


Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: zakk on 27-09-2013, 10:58:07
pa onda i mi da spalimo znak sagite odma...
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 27-09-2013, 11:29:50
 xptit
pa onda i mi da spalimo znak sagite odma...

 
A što?  :shock: Nije valjda da ovde nešto ne valja?  :-? Otkud sad to odjedared? *treptrep* Da ti nije malko to hard to larboard fenomen? Sve mi se javlja da se ovde nekad nešto drugo mislilo… a i radilo… kako ono beše… “valjaju paprike i na džak kad se kupuju”, a?  :mrgreen: 
Al’ dobro, bolje da nije nikom ni važno, a ne bi ni valjalo da danas nekog grize savest, nedajbože. Lakše spalit ceo forum, sad kad nije za one koji vole u kafanu na stolovi da tvituju.  :evil: :evil:   :lol:
 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: zakk on 27-09-2013, 12:00:31
U svakoj šali ima zrnce zbilje, ali ovo je ipak šala, dakle, opusti se...  :roll:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 27-09-2013, 12:25:25
 Aman… pa čega to neopuštenog ima u mom pokušaju da ti skrenem pažnju kako se šegačiš  sa situacijom na koju skoro da posredni kopirajt polažeš? To je kao kad Mehu uhvati da dramakviniše što se ljudi ne ponašaju u skladu sa petom im decenijom trajanja… missim, kamaun pipl!  :roll:
 
 
A što se same afere tiče, jeste da je malko polarizovala ljude na fb, ali pretegli su izgleda argumenti u podršku. ‘Isključivanje ludila’ je ne samo validna nego i obavezna odbrana diskursa a moderacija (ma kako strikntna i ažurna) po svojoj prirodi nije adekvatna alatka u tom konkretnom naporu: moderator ne samo da ne može da isključi ludilo (u većini slučajeva neće ni da ga prepozna na vreme, ionako), nego naprosto mora da razmotri sve priloge u svom mehanizmu procenjivanja, otud – moderator svim prilozima jednako pristupa, jednako ih procenjuje i jednako razmatra, to bar do odluke o njihovom ukljanjanju. To ga čini neselektivnim, naravno, pa otud i beskorisnim. A da i ne govorim o delikatnim situacijama u kojima se mora razmotriti i sasvim trezven i lucidan post kojim neko zaludan odgovara ludaku/provokatoru… to je najgora od svih dilema, da li to brisati ili ne. Zato, ovo što PS radi je, po meni, naidealnija opcija.
 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Mica Milovanovic on 27-09-2013, 15:11:45
Ja razumem tvoj gnev, jer bih i sam često poželeo da pobrišem dve trećine postova sa ZS-a, ali moraš da priznaš da nije isto moderisanje ZS-a i PS-a. Ovo je, ipak forum. Ne važe isti principi...
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 27-09-2013, 18:59:55
To o principima je već stvar tačke gledišta, dozvolićeš. Govorila sam o generalnom očuvanju diskursa, to bilo kog tematskog, pa zašto ne i ovog, na kraju krajeva? Koju to tačno svrhu ima bilo kakvo podsticanje učesnika koji očigledno ne vladaju ni zdravim razumom, a kamoli tematikom razgovora? Ja mogu da dozvolim mogućnost da se to radi u svrhu zabave, to od neke prizemnije vrste - i ja sebi zabave nalazim tamo gde neko pametniji ne bi - ali ako je već tako, onda bar ne budimo licemeri da se kasnije nad upravo takvom situacijom kobajagi zgražamo. Popravite to što možete, a što ne možete, pa to onda barem ignorišite, nije ovde niko slep pa da ne vidi nivo fekalije čiju su produkciju baš vajni upirači prstom najizdašnije producirali, to između svih nas grešnih ostalih. Kakav je to fazon da se ovde svraća samo sa podjebljivo-duhovitim onelinerima?


A ako o direktnom moderisanju već govorimo, onda bi isto tako fer bilo priznati da je upravo ovo forum najgadnije moderisan od sviju za koje znam: ovo je forum iza čije silne i surove moderacije ne leži nikakav prepoznatljiv mehanizam, niti bilo kakva meni prepoznatljiva logika, to van njihove prosto trenutačne (znači, intuitivne, pa stoga i slepački kratkoročne) samovolje.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Mica Milovanovic on 27-09-2013, 20:04:31
Mož' biti da si u pravu. Ipak, učestalost moderacije je toliko mala da se to relativno slabo oseća...
Reči: "silne" i "surove" su možda preterane...
Ali, ostavimo to ličnom utisku. Ne bih da polemišem po ovom pitanju i doprinosim zabavi dokonih...
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 27-09-2013, 20:19:43
Mož' biti da si u pravu. Ipak, učestalost moderacije je toliko mala da se to relativno slabo oseća...



E da, to mi kaže čovek kojem nikada niti jedan post sa foruma nije bio uklonjen - to ako ne računamo sve one postove koji su uklonjeni zajedno sa celim topicima, jelte, ali na te rane nećemo okeansku so da sada sipamo - pa se stoga sad tebi i otvara to pitanje strogosti moderacije. A pošto si ti - ti, a ja sam samo ja, ostavićemo mogućnost da si ti u svim postovima bio u pravu, a ja sam u mnogima bila u krivu. Bolje to nego da brojimo bilo šta drugo.


Sa ostalim navodima u tvom postu se apsolutno slažem i računam da baš zato nama dvoma i ne treba fenomen moderacije, jer eto, mi oboje znamo to što znamo, mada očigledno nismo jednako u tom znanju bogatiji.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 04-10-2013, 09:53:17
Dalje dileme vezane za komentarisanje naučnih pisanija po Internetu:

Closing Commenting (http://scienceblogs.com/gregladen/2013/10/02/closing-commenting/)

Quote
  Popular Science, one of the longest running and, well, popular, magazines that deals with science has a website (http://www.popsci.com/). Last Tuesday, on-line editor Suzanne LaBarre announced that Popular Science would no longer have comment sections on most of its pages.  The reason sited was that “Comments can be bad for science.”  She noted (http://www.popsci.com/science/article/2013-09/why-were-shutting-our-comments):
 
A politically motivated, decades-long war on expertise has eroded the popular consensus on a wide variety of scientifically validated topics. Everything, from evolution to the origins of climate change, is mistakenly up for grabs again. Scientific certainty is just another thing for two people to “debate” on television. And because comments sections tend to be a grotesque reflection of the media culture surrounding them, the cynical work of undermining bedrock scientific doctrine is now being done beneath our own stories, within a website devoted to championing science.
She is absolutely correct.  It seems, in fact, that attacking science in the comment sections of blogs and web sites is a cottage industry practiced vigorously by a very active minority of readers (we hope). And it may well be effective.  Last January, Chris Mooney wrote:
 
Everybody who’s written or blogged about climate change on a prominent website (or, even worse, spoken about it on YouTube) knows the drill. Shortly after you post, the menagerie of trolls arrives. They’re predominantly climate deniers, and they start in immediately arguing over the content and attacking the science—sometimes by slinging insults and even occasional obscenities.
Chris talks about a study (http://www.motherjones.com/environment/2013/01/you-idiot-course-trolls-comments-make-you-believe-science-less) done by researchers at George Mason University Center for Climate Change Communication (and others) that showed that these negative comments can be effective in ruining readers’ perception of the validity of science written about on line.   
 
The study did not examine online climate change trolls directly—but there is good reason to think that the effects of their obnoxious behavior will, if anything, be worse. … When it comes to climate change… “the controversy that you see in comments falls on more fertile ground, and resonates more with an established set of values that the reader may bring to the table,” explains study coauthor Dietram Scheufele, … If commenters have stronger emotions and more of a stake, it stands to reason that the polarizing effect of their insults may be even stronger—although, to be sure, this needs to be studied.
… This is not your father’s media environment any longer. In the golden oldie days of media, newspaper articles were consumed in the context of…other newspaper articles. But now, adds Scheufele, it’s like “reading the news article in the middle of the town square, with people screaming in my ear what I should believe about it.”
(Click through to CM’s post to get the link to that study.)
Chris told me “It is indeed possible to moderate comments to make them productive, but it is a huge amount of work. So I’m not that surprised that Popular Science opted not to do it.”
Will Oremus writing at Slate disagrees. He notes (http://www.slate.com/blogs/future_tense/2013/09/25/popular_science_says_comments_bad_for_science_shuts_them_off_bad_move.html):
 
Sure, some very important scientific questions are pretty much settled … But LaBarre’s metaphors conjure an image of science as an ancient and immovable stone fortress, from which the anointed few (Popular Science staff writers, say) may cast pearls in the direction of the masses below, but which might crumble to dust if the teeming throngs aren’t kept at bay. This conception is antithetical to the spirit of free inquiry that has always driven scientific discovery.
And here, in Will Oremus’s comment (and elsewhere) I see a flaw. The assumption implicit (or not so implicit) in Oremus’s commentary in Slate is that comments contribute to the science directly, by becoming part of the “spirit of free inquiry.” And I’m sure this is a feeling shared by many of the comment trolls of whom we are speaking.
The problem is, this is largely a made up fantasy.  There are two distinct things going on here. One is science, which involves free inquiry and lots of communication among scientists, and the other is public understanding of science, which is very important because it is a key part of the process of translating science knowledge into science policy, especially in a society that thinks of itself as a democracy. 
The comment trolls are not ruining science.  They are ruining public perception of science.  The commentary on web sites and blog posts is not part of the science conversation that produces scientific results (or, if so, rarely). 
I wrote an opinion piece for The Scientist expressing this view, and it was put up this morning. Please go and have a look:  Opinion: Part of the Conversation? On whether online comments help or hurt science (http://www.the-scientist.com/?articles.view/articleNo/37743/title/Opinion--Part-of-the-Conversation-/).
If you have a comment on any of this, please feel free to add it to the page at The Scientist, or below, or both.  I don’t have any control over the comment section at The Scientist, but here on this blog, have at it, even if you are a troll, as long as you are not a spam bot (and I can tell the difference, usually). 
 

Evo i celog drugog Gregovog članka:



Opinion: Part of the Conversation? (http://www.the-scientist.com/?articles.view/articleNo/37743/title/Opinion--Part-of-the-Conversation-/)



Quote

Where in science do we find free inquiry, vigorous debate, open and frank discussion of research, and productive—if sometimes acrimonious—conversations about methods, data, findings, interpretation, and implications? Most of these conversations happen in the comment sections of blogs and other websites, right?
 
 Actually, no.
 
 These conversations happen elsewhere. For example, many research labs hold weekly meetings that all members attend. There are e-mail lists used by groups of scientists working at diverse institutions to hash out their methods, share data, and challenge one another’s interpretations. Then there are more formal settings, such as conferences, where some give talks while others prowl the hallways, cafeterias, local pubs, and hotel lounges getting in touch with colleagues, exchanging ideas, making plans, and renewing their contacts with fellow scientists. And there are many other fora that are much better suited to discussing science than the comment sections that accompany most blog posts and news reports. Arguably, peer review is the ultimate conversation in science.
 While notes left on blogs and websites are not part of this formalized process, some people do have meaningful discussions of scientific issues in the comment sections of these sites. These conversations can be quite interesting and informative, but they have virtually nothing to do with how science is done. Some scientists engage in online commenting now and then, but when they do, it is almost always to lend their support to science when a reported finding is challenged by anti-science trolls.
 
 I’ve written many blog posts that report on scientific findings. In doing so, I often send a link to the researchers involved in the work, inviting them to participate in the comments. They almost never do, though when they have, I’ve never seen the resulting conversation replicate a discussion that might occur within the science community.
 
 Recently, PopularScience.com—the website of the eponymous magazine—decided to shut down commenting (http://www.popsci.com/science/article/2013-09/why-were-shutting-our-comments) on most of its pages. Popular Science said its comment sections had become polluted with trolls and spambots. While the publication could have spent additional resources policing, cleaning up, and even redirecting the conversations on those pages, its staff instead elected to eliminate this public forum.
  Some have complained, suggesting that the commentary on these pages—or on blogs and websites more generally—is somehow part of the scientific process, and that closing out comments will have a negative effect on inquiry. But removing the comment boxes from these web pages will have little to no effect on what scientists are doing. To my mind, Popular Science is not doing science any harm.     Even so, while science may not be at risk, public understanding of science certainly is. Non-scientists with a thirst for scientific knowledge read websites like Popular Science, The Scientist, and ScienceBlogs, and indeed, members of the general public can learn and engage in the comment sections of these sites. But if the comments have become infested with trolls, then that’s all been ruined and there is not much hope of advancing the general understanding of science by preserving such a forum. Troll-infested fora negatively impact the public side of scientific discourse. We should not encourage—and certainly should not protect—virtual soapboxes for anti-science blather.     As a blogger, I understand how difficult managing online comments can be. A couple of years ago, I got strict with commenting on my blog in an effort to shun the science denialists. I let the occasional questionable comment through, but made it clear my blog would not be a platform for people engaged in what I regard as a nefarious activity: diverting progress by messing with our single most important resource—knowledge. When I implemented that rule, I did not see a drop in my readership. Rather, I received numerous appreciative e-mails, and significantly reduced my use of antacids. I suspect the Popular Science editors are experiencing a similar sense of relief now.     Online discourse is a good thing, and it has become part of our Internet Culture, but there is no rule that says that every page on this World Wide Web needs a comment box at the bottom of it.     Greg Laden is a biological anthropologist and science communicator who has done research in the evolution of human diet and ecology. His blog  (http://scienceblogs.com/gregladen/)is hosted by ScienceBlogs.com.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 04-10-2013, 09:58:26
Daily Tech, pak ima suprotno mišljenje i mada se u ovom tekstu insistira da naučnik ne mora ni u šta da veruje jer on uvek samo posmatra realnost, što nije baš sasvim istina u najširem smislu, članak je ipak zdravo pročitati.

 
Editorial: PopSci Kills Comments, Blames Global Warming, Evolution (http://www.dailytech.com/Editorial+PopSci+Kills+Comments+Blames+Global+Warming+Evolution/article33437.htm)


Quote
Comments interfere with preaching a "scientific doctrine" (presumably a religion of sorts), according to PopSci

 First they came for the BoingBoing comments (http://boingboing.net/2013/06/28/in-case-you-missed-a-roundup.html), then they came for the Popular Science comments (http://www.popsci.com/science/article/2013-09/why-were-shutting-our-comments?src=SOC&dom=tw), then they came for... wait, that pretty much sums up the current state of affairs.  After BoingBoing opted to scrap its in-article comments for a forum in a few months back in June, PopSci just announced its decision to follow in suit with an article entitled "Why We're Shutting Off Our Comments".  This remarkable act of reader censorship is backed by a number of questionable assertions -- most notably the notion that reader comments undermine the preaching of a "scientific doctrine" and that "comments are bad for science." 
 
 (The New York Times has also scaled back comments (http://6thfloor.blogs.nytimes.com/2013/09/20/comments-on-comments/?_r=0), disabling them entirely in some pieces.)
 
 I. Censorship, the Tired Retreat of the Thin Skinned
 
 These decisions may smack some as subjective or even malicious.  After all comments are arguably the digital age response to print's "letter to the editor" -- and they often contain criticisms of the article ranging from grammatical erorrs to factual oversights.  Some may view the decision to ban comments as a form of censorship, a means for writers to escape any sort of visible accountability among their audience.
 
 And while moderation of extreme trolling is at times necessary, comments provide an essential outlet for user opinion.




But PopSci argues that the evil of comments outweighs their merits.  It says that it has been ovewhelmed by "trolls and spambots (http://www.dailytech.com/Arizona+Internet+Trolling+Bill+HB+2549+Causes+Privacy+Uproar+Lawmakers+Making+Changes+/article24384.htm)" and its editor Suzanne LaBarre writes: 
 Comments can be bad for science. That's why, here at PopularScience.com, we're shutting them off.
 And since the blog is about science they at least attempt to back their conclusion with a scientific study -- a journal paper published by Dominique Brossard (http://lsc.wisc.edu/people/faculty/dominique-brossard/) a Life Sciences Communication (http://lsc.wisc.edu/) professor at the Univ. of Wisconsin-Madison (http://www.wisc.edu/).  Published in the February 2013 edition (http://onlinelibrary.wiley.com/doi/10.1111/jcc4.12009/full) of the peer-reviewed Journal of Computer-Mediated Communications, Professor Brossard's study involved perceptions of a fictious nanotechnology article (http://www.dailytech.com/It+Cuts+Both+Ways+American+Majority+Deems+Nanotechnology+Immoral/article10822.htm), which people were asked to react to. 
 
 People reacted neutrally when comments were disabled, but even when comments were generally positive their reactions did not noticeably improved.  However, when the reader feedback took on a "less civil" tone with people questioning the merits of nanotechnology, user perception of the publication itself (not just the topic discussed) took a decidedly negative turn.
 
 II. PopSci Complains That Comments Interfere With Its Ability to "Indoctrinate" Readers
 
 PopSci piece also in a roundabout way suggests it had to revoke its users' commenting rights due to their criticisms of studies on global warming.  It writes: 
 A politically motivated, decades-long war on expertise has eroded the popular consensus on a wide variety of scientifically validated topics. Everything, from evolution to the origins of climate change, is mistakenly up for grabs again. Scientific certainty is just another thing for two people to "debate" on television.
 
 And because comments sections tend to be a grotesque reflection of the media culture surrounding them, the cynical work of undermining bedrock scientific doctrine is now being done beneath our own stories, within a website devoted to championing science.

 She cites an editorial (http://www.nytimes.com/2013/08/22/opinion/welcome-to-the-age-of-denial.html) in The New York Times voicing similar complaints.



But it is Ms. LaBarre's use of the phrase "scientific doctrine" which should is most interesting, and perhaps telling.  The root word of indoctrination -- brainwashing with a rigid set set of beliefs -- is "doctrine".  Indeed the Wikipedia entry for "doctrine" states:  Doctrine (from Latin: doctrina) is a codification of beliefs or a body of teachings or instructions, taught principles or positions, as the body of teachings in a branch of knowledge or belief system. The Greek analogue is the etymology of catechism.[1]
 Often doctrine specifically connotes a corpus of religious dogma as it is promulgated by a church, but not necessarily: doctrine is also used to refer to a principle of law...

 And Google Inc.'s (GOOG (http://www.nasdaq.com/symbol/GOOG)) built in dictionary describes doctrine as: 
 a belief or set of beliefs held and taught by a church, political party, or other group.
 Science has little to do with beliefs.  Science is the process of observation, of collecting hard, repeatable evidence.  Belief is unnecessary to a scientist who does their job right, as they are simply studying reality.
 
 The phrase seems decidedly odd as coming from a science publication: after all isn't open, informed debate the root of all science?  Since when has indoctrination -- peddling of a set of rigid, unquestioning beliefs (http://www.dailytech.com/Top+Physics+Professor+Resigns+From+Post+Denouncing+Global+Warming+Fraud/article19879.htm), most often associated with religion (http://www.dailytech.com/Study+Indicates+Evolution+Disbelief+is+Fueled+by+Fear+of+the+Uncertain/article19743.htm) -- become part of the scientific process?

 
 Perhaps lack of critical feedback, user bickering, and spam may indeed improve the perception of PopSci.  But it's hard to imagine Socrates or Plato, were they alive today, shutting the door to public commentary.  After all, as journalists we all have to remember we aren't actually doing science -- at least not at our news jobs -- we're simply trying to represent it in a clear and concise form that the public can understand and enjoy.



While PopSci writes "we have many delightful, thought-provoking commenters," it's hard to escape the impression that its editors think themselves greater science minds than their readership.  Perhaps that's why they're so eager to "indoctrinate" readers (quite literally what Ms. LaBarre says is the site's goals) with their superior wisdom (i.e. interpretations) of science.
 
 But here at DailyTech we take a different view.  We reject censorship and believe in free expression.
 
 We welcome all opinions from the novice to the professional.  We welcome respectful criticism of our authors, our articles, and the material therein, in a public place for all to see.  We don't believe doctrines and indoctrination have a place in open scientific discussion.
 
 At the same time we acknowledge that comments -- criticism, trolling, and more -- are a painful burden at times.  But it is a burden we choose to bear because we must.  Perhaps it will hurt our readers' impressions of our site.  But journalism and science are founded upon open discourse and a receptiveness to feedback.  Once you lose that, you risk rapid loss of your accountability and credibility.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 04-10-2013, 10:43:27
 Heh… ovaj Daily Tech editorijal post meni zapravo totalno ilustruje problem: kanda je malko isuviše vitrioličan po svom tonu, pa se zbog toga još lakše gubi ona ionako tanka linija između argumenta i manipulacije. A i pančlajn je tu pristigao baš kao poslednja kap da ga sasvim sjuri u manipulaciju: “But journalism and science are founded upon open discourse and a receptiveness to feedback.  Once you lose that, you risk rapid loss of your accountability and credibility.” Mda.  Ajde što su receptivnost na fidbek u novinarstvu i nauci baš babe i žabe, sve i ako se makar u istoj diskursnoj vodi brčkaju, ali bogami je i svakom normalnom kristalno jasno da je otvoreni diskurs jedno, a nekompetentno komentarisanje nešto sasvim drugo. Novinarstvo skoro da počiva na potrošačkom fidbeku a nauka bogami baš i ne, teško da se naučne teze potvrđuju ili osporavaju korisničkim komentarima, biće da tu ipak ima neka druga procedura. A i insinuacija o ‘PS malicioznom cenzoršipu’ je baš zdravo maliciozna, pošto je čak i laiku očigledno da ova vrst kontrolisanja internetske konverzacije neće nauditi kredibilitetu same nauke, nego samo izvesnog vida popularizacije nauke ( a i to je otvoreno pitanje, ja čak ne mislim ni da će uopšte nauditi, naprotiv), a to uopšte nije isto.
Ne znam ko to iskreno očekuje da će se išta merljivo korisno izvući iz laičkih komentara na sajtu, a oni čiji bi komentari mogli biti korisni, pa, ti teško da će ih baš tako prosipati na open discourse internet sajt.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 04-10-2013, 10:58:44
pošto je čak i laiku očigledno da ova vrst kontrolisanja internetske konverzacije neće nauditi kredibilitetu same nauke, nego samo izvesnog vida popularizacije nauke

Pa, to. To je srž rasprave, čini mi se.

S druge strane, ja sam gore već u originalnom postu rekao da mislim da je rešenje u boljoj moderaciji (eventualno automoderaciji od strane samog čitalaštva) jer ona omogućuje da rasprava bude struktuirana dobro, pa makar i najpopularniji komentari bili drsko nenaučni. To onda barem pokazuje šta svet o čemu misli i koje su teze koje publicistika onda treba da uzme u obzir u daljem radu.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 04-10-2013, 11:17:40
 Generalno govoreći, i u nekom idealnom svetu, bio bi potpuno u pravu. Ali u izostanku toga, već je urednica naglasila u čemu je problem: štetnost takve konkretno onlajn situacije po pravilu nadmaši njen eventualni benefit, tako da je upravo taj finalni skor bio razlog donošenju njena konkretne odluke. E sad, ako sa jedne strane imaš merljiv i konkretan učinak a sa druge strane imaš generalnu odbranu principa popularizacije i njenog specifičnog diskursa… šta ja znam, meni je njena odluka ipak logičnija, valjda zato jer je smatram korisnijom.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 04-10-2013, 11:39:46
Da, mislim da je kod mene u pitanju to da branim princip kao svetinju i da podrazumevam da komentari kakvi god bili ne mogu da "oštete" originalni članak jer sumnjam da ih više od 10% čitalaca uopšte pogleda. Ali to je samo mišljenje, naravno.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 04-10-2013, 12:00:09
 Kad odrasteš, shvatićeš da je đavo u detaljima konteksta.   :evil:
Ali sad na ozbiljniju notu - i ja sebe smatram poslednjom osobom koja bi posegla za cenzurom, otud i pravim vrednosnu razliku između moderacije (koju zastupaš ti) i embarga (kojem se sve više priklanjam ja):  a ako se bez moderacije baš nikako ne može, onda mi bolja tišina. Čujem ponekad kako ljudi mrtvi-ozbiljni izjavljuju bedastoće primerenije mračnom četrnaestom veku i eto, bolja mi tišina. (Znaš za onu scenu iz WWZ kada na biciklima tiho idu da napune avion gorivom a onda mu nesretniku zazvrnda mobilni? To je to, to je naprosto zdravorazumski ustupak, da se isključi mobilni, jer se mora. )
Ali okej je meni ako ti hoćeš da braniš baš taj princip kao svetinju, neko valjda i to mora da radi, a ja odoh sad da budem malo i korisna.    :)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 04-10-2013, 12:11:50
Razumem to da je čoveku bolja tišina nego da sluša lupetanja, naravno. Samo sam valjda skloniji tome da je bitno i da se čuju lupetanja jer onda znaš šta ljudi misle i kako da nekom drugom prilikom formulišeš svoje teze itd. Pogotovo što pričamo baš o publicistici koja treba da poplariše nauku. Ali naravno da to zahteva napor za koji ne može čovek uvek da bude raspoložen...
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 05-10-2013, 08:28:49
I sa druge strane, ne treba da nas iznenadi što i američki naučnici rade isto što i naši: napišu "naučni" rad prepun očiglednih besmislica sa očigledno izmišljenim referencama a onda gledaju da li će urednici "naučnih" publikacija da ih objave. U našem slučaju (kako je to na ovom topiku dokumentovao Gul (http://www.znaksagite.com/diskusije/index.php/topic,13215.msg522338.html#msg522338)) radilo se samo o slanju jednom rumunjskom magazinu. U američkom slučaju, čovek je poslao rad na preko trista adresa i na više od pola je objavljen:
 Who's Afraid of Peer Review? (http://www.sciencemag.org/content/342/6154/60.full)
 
Quote
A spoof paper concocted by Science reveals little or no scrutiny at many open-access journals.
 
On 4 July, good news arrived in the inbox of Ocorrafoo Cobange, a biologist at the Wassee Institute of Medicine in Asmara. It was the official letter of acceptance for a paper he had submitted 2 months earlier to the Journal of Natural Pharmaceuticals, describing the anticancer properties of a chemical that Cobange had extracted from a lichen.
 
In fact, it should have been promptly rejected. Any reviewer with more than a high-school knowledge of chemistry and the ability to understand a basic data plot should have spotted the paper's short-comings immediately. Its experiments are so hopelessly flawed that the results are meaningless.
 
I know because I wrote the paper. Ocorrafoo Cobange does not exist, nor does the Wassee Institute of Medicine. Over the past 10 months, I have submitted 304 versions of the wonder drug paper to open-access journals. More than half of the journals accepted the paper, failing to notice its fatal flaws. Beyond that headline result, the data from this sting operation reveal the contours of an emerging Wild West in academic publishing.
 
 
From humble and idealistic beginnings a decade ago, open-access scientific journals have mushroomed into a global industry, driven by author publication fees rather than traditional subscriptions. Most of the players are murky. The identity and location of the journals' editors, as well as the financial workings of their publishers, are often purposefully obscured. But Science's investigation casts a powerful light. Internet Protocol (IP) address traces within the raw headers of e-mails sent by journal editors betray their locations. Invoices for publication fees reveal a network of bank accounts based mostly in the developing world. And the acceptances and rejections of the paper provide the first global snapshot of peer review across the open-access scientific enterprise.
 
One might have expected credible peer review at the Journal of Natural Pharmaceuticals. It describes itself as "a peer reviewed journal aiming to communicate high quality research articles, short communications, and reviews in the field of natural products with desired pharmacological activities." The editors and advisory board members are pharmaceutical science professors at universities around the world.
 
The journal is one of more than 270 owned by Medknow, a company based in Mumbai, India, and one of the largest open-access publishers. According to Medknow's website, more than 2 million of its articles are downloaded by researchers every month. Medknow was bought for an undisclosed sum in 2011 by Wolters Kluwer, a multinational firm headquartered in the Netherlands and one of the world's leading purveyors of medical information with annual revenues of nearly $5 billion.
 
But the editorial team of the Journal of Natural Pharmaceuticals, headed by Editor-in-Chief Ilkay Orhan, a professor of pharmacy at Eastern Mediterranean University in Gazimagosa, Cyprus, asked the fictional Cobange for only superficial changes to the paper—different reference formats and a longer abstract—before accepting it 51 days later. The paper's scientific content was never mentioned. In an e-mail to Science, managing editor Mueen Ahmed, a professor of pharmacy at King Faisal University in Al-Hasa, Saudi Arabia, states that he will permanently shut down the journal by the end of the year. "I am really sorry for this," he says. Orhan says that for the past 2 years, he had left the journal's operation entirely to staff led by Ahmed. (Ahmed confirms this.) "I should've been more careful," Orhan says.
 
Acceptance was the norm, not the exception. The paper was accepted by journals hosted by industry titans Sage and Elsevier. The paper was accepted by journals published by prestigious academic institutions such as Kobe University in Japan. It was accepted by scholarly society journals. It was even accepted by journals for which the paper's topic was utterly inappropriate, such as the Journal of Experimental & Clinical Assisted Reproduction.
 
The rejections tell a story of their own. Some open-access journals that have been criticized for poor quality control provided the most rigorous peer review of all. For example, the flagship journal of the Public Library of Science, PLOS ONE, was the only journal that called attention to the paper's potential ethical problems, such as its lack of documentation about the treatment of animals used to generate cells for the experiment. The journal meticulously checked with the fictional authors that this and other prerequisites of a proper scientific study were met before sending it out for review. PLOS ONE rejected the paper 2 weeks later on the basis of its scientific quality.
  Down the rabbit hole The story begins in July 2012, when the Science editorial staff forwarded to me an e-mail thread from David Roos, a biologist at the University of Pennsylvania. The thread detailed the publication woes of Aline Noutcha, a biologist at the University of Port Harcourt in Nigeria. She had taken part in a research workshop run by Roos in Mali in January last year and had been trying to publish her study of Culex quinquefasciatus, a mosquito that carries West Nile virus and other pathogens.
Noutcha had submitted the paper to an open-access journal called Public Health Research. She says that she believed that publication would be free. A colleague at her university had just published a paper for free in another journal from the same publisher: Scientific & Academic Publishing Co. (SAP), whose website does not mention fees. After Noutcha's paper was accepted, she says, she was asked to pay a $150 publication fee: a 50% discount because she is based in Nigeria. Like many developing world scientists, Noutcha does not have a credit card, and international bank transfers are complicated and costly. She eventually convinced a friend in the United States to pay a fee further reduced to $90 on her behalf, and the paper was published. 
 Roos complained that this was part of a trend of deceptive open-access journals "parasitizing the scientific research community." Intrigued, I looked into Scientific & Academic Publishing. According to its website, "SAP serves the world's research and scholarly communities, and aims to be one of the largest publishers for professional and scholarly societies." Its list includes nearly 200 journals, and I randomly chose one for a closer look. The American Journal of Polymer Science describes itself as "a continuous forum for the dissemination of thoroughly peer-reviewed, fundamental, international research into the preparation and properties of macromolecules." Plugging the text into an Internet search engine, I quickly found that portions had been cut and pasted from the website of the Journal of Polymer Science, a respected journal published by Wiley since 1946.
I began to wonder if there really is anything American about the American Journal of Polymer Science. SAP's website claims that the journal is published out of Los Angeles. The street address appears to be no more than the intersection of two highways, and no phone numbers are listed.
I contacted some of the people listed as the journal's editors and reviewers. The few who replied said they have had little contact with SAP. Maria Raimo, a chemist at the Institute of Chemistry and Technology of Polymers in Naples, Italy, had received an e-mail invitation to be a reviewer 4 months earlier. To that point, she had received a single paper—one so poor that "I thought it was a joke," she says.
Despite her remonstrations to the then–editor-in-chief, a person of unknown affiliation called David Thomas, the journal published the paper. Raimo says she asked to be removed from the masthead. More than a year later, the paper is still online and the journal still lists Raimo as a reviewer.
After months of e-mailing the editors of SAP, I finally received a response. Someone named Charles Duke reiterated—in broken English—that SAP is an American publisher based in California. His e-mail arrived at 3 a.m., Eastern time.
To replicate Noutcha's experience, I decided to submit a paper of my own to an SAP journal. And to get the lay of this shadowy publishing landscape, I would have to replicate the experiment across the entire open-access world.
   The targets The Who's Who of credible open-access journals is the Directory of Open Access Journals (DOAJ). Created 10 years ago by Lars Bjørnshauge, a library scientist at Lund University in Sweden, the DOAJ has grown rapidly, with about 1000 titles added last year alone. Without revealing my plan, I asked DOAJ staff members how journals make it onto their list. "The title must first be suggested to us through a form on our website," explained DOAJ's Linnéa Stenson. "If a journal hasn't published enough, we contact the editor or publisher and ask them to come back to us when the title has published more content." Before listing a journal, they review it based on information provided by the publisher. On 2 October 2012, when I launched my sting, the DOAJ contained 8250 journals and abundant metadata for each one, such as the name and URL of the publisher, the year it was founded, and the topics it covers.
There is another list—one that journals fear. It is curated by Jeffrey Beall, a library scientist at the University of Colorado, Denver. His list is a single page on the Internet that names and shames what he calls "predatory" publishers. The term is a catchall for what Beall views as unprofessional practices, from undisclosed charges and poorly defined editorial hierarchy to poor English—criteria that critics say stack the deck against non-U.S. publishers.
Like Batman, Beall is mistrusted by many of those he aims to protect. "What he's doing is extremely valuable," says Paul Ginsparg, a physicist at Cornell University who founded arXiv, the preprint server that has become a key publishing platform for many areas of physics. "But he's a little bit too trigger-happy."
I asked Beall how he got into academic crime-fighting. The problem "just became too bad to ignore," he replied. The population "exploded" last year, he said. Beall counted 59 predatory open-access publishers in March 2012. That figure had doubled 3 months later, and the rate has continued to far outstrip DOAJ's growth.
To generate a comprehensive list of journals for my investigation, I filtered the DOAJ, eliminating those not published in English and those without standard open-access fees. I was left with 2054 journals associated with 438 publishers. Beall's list, which I scraped from his website on 4 October 2012, named 181 publishers. The overlap was 35 publishers, meaning that one in five of Beall's "predatory" publishers had managed to get at least one of their journals into the DOAJ.
I further whittled the list by striking off publishers lacking a general interest scientific journal or at least one biological, chemical, or medical title. The final list of targets came to 304 open-access publishers: 167 from the DOAJ, 121 from Beall's list, and 16 that were listed by both. (Links to all the publishers, papers, and correspondence are available online at http://scim.ag/OA-Sting (http://scim.ag/OA-Sting).)
   The bait The goal was to create a credible but mundane scientific paper, one with such grave errors that a competent peer reviewer should easily identify it as flawed and unpublishable. Submitting identical papers to hundreds of journals would be asking for trouble. But the papers had to be similar enough that the outcomes between journals could be comparable. So I created a scientific version of Mad Libs.
The paper took this form: Molecule X from lichen species Y inhibits the growth of cancer cell Z. To substitute for those variables, I created a database of molecules, lichens, and cancer cell lines and wrote a computer program to generate hundreds of unique papers. Other than those differences, the scientific content of each paper is identical.
The fictitious authors are affiliated with fictitious African institutions. I generated the authors, such as Ocorrafoo M. L. Cobange, by randomly permuting African first and last names harvested from online databases, and then randomly adding middle initials. For the affiliations, such as the Wassee Institute of Medicine, I randomly combined Swahili words and African names with generic institutional words and African capital cities. My hope was that using developing world authors and institutions would arouse less suspicion if a curious editor were to find nothing about them on the Internet.
The papers describe a simple test of whether cancer cells grow more slowly in a test tube when treated with increasing concentrations of a molecule. In a second experiment, the cells were also treated with increasing doses of radiation to simulate cancer radiotherapy. The data are the same across papers, and so are the conclusions: The molecule is a powerful inhibitor of cancer cell growth, and it increases the sensitivity of cancer cells to radiotherapy.
There are numerous red flags in the papers, with the most obvious in the first data plot. The graph's caption claims that it shows a "dose-dependent" effect on cell growth—the paper's linchpin result—but the data clearly show the opposite. The molecule is tested across a staggering five orders of magnitude of concentrations, all the way down to picomolar levels. And yet, the effect on the cells is modest and identical at every concentration.
One glance at the paper's Materials & Methods section reveals the obvious explanation for this outlandish result. The molecule was dissolved in a buffer containing an unusually large amount of ethanol. The control group of cells should have been treated with the same buffer, but they were not. Thus, the molecule's observed "effect" on cell growth is nothing more than the well-known cytotoxic effect of alcohol.
The second experiment is more outrageous. The control cells were not exposed to any radiation at all. So the observed "interactive effect" is nothing more than the standard inhibition of cell growth by radiation. Indeed, it would be impossible to conclude anything from this experiment.
To ensure that the papers were both fatally flawed and credible submissions, two independent groups of molecular biologists at Harvard University volunteered to be virtual peer reviewers. Their first reaction, based on their experience reviewing papers from developing world authors, was that my native English might raise suspicions. So I translated the paper into French with Google Translate, and then translated the result back into English. After correcting the worst mistranslations, the result was a grammatically correct paper with the idiom of a non-native speaker.
The researchers also helped me fine-tune the scientific flaws so that they were both obvious and "boringly bad." For example, in early drafts, the data were so unexplainably weird that they became "interesting"—perhaps suggesting the glimmer of a scientific breakthrough. I dialed those down to the sort of common blunders that a peer reviewer should easily interdict.
The paper's final statement should chill any reviewer who reads that far. "In the next step, we will prove that molecule X is effective against cancer in animal and human. We conclude that molecule X is a promising new drug for the combined-modality treatment of cancer." If the scientific errors aren't motivation enough to reject the paper, its apparent advocacy of bypassing clinical trials certainly should be.
   The sting Between January and August of 2013, I submitted papers at a rate of about 10 per week: one paper to a single journal for each publisher. I chose journals that most closely matched the paper's subject. First choice would be a journal of pharmaceutical science or cancer biology, followed by general medicine, biology, or chemistry. In the beginning, I used several Yahoo e-mail addresses for the submission process, before eventually creating my own e-mail service domain, afra-mail.com, to automate submission.
A handful of publishers required a fee be paid up front for paper submission. I struck them off the target list. The rest use the standard open-access "gold" model: The author pays a fee if the paper is published.
If a journal rejected the paper, that was the end of the line. If a journal sent review comments that asked for changes to layout or format, I complied and resubmitted. If a review addressed any of the paper's serious scientific problems, I sent the editor a "revised" version that was superficially improved—a few more photos of lichens, fancier formatting, extra details on methodology—but without changing any of the fatal scientific flaws.
After a journal accepted a paper, I sent a standard e-mail to the editor: "Unfortunately, while revising our manuscript we discovered an embarrassing mistake. We see now that there is a serious flaw in our experiment which invalidates the conclusions." I then withdrew the paper.
   The results By the time Science went to press, 157 of the journals had accepted the paper and 98 had rejected it. Of the remaining 49 journals, 29 seem to be derelict: websites abandoned by their creators. Editors from the other 20 had e-mailed the fictitious corresponding authors stating that the paper was still under review; those, too, are excluded from this analysis. Acceptance took 40 days on average, compared to 24 days to elicit a rejection.
Of the 255 papers that underwent the entire editing process to acceptance or rejection, about 60% of the final decisions occurred with no sign of peer review. For rejections, that's good news: It means that the journal's quality control was high enough that the editor examined the paper and declined it rather than send it out for review. But for acceptances, it likely means that the paper was rubber-stamped without being read by anyone.
Of the 106 journals that discernibly performed any review, 70% ultimately accepted the paper. Most reviews focused exclusively on the paper's layout, formatting, and language. This sting did not waste the time of many legitimate peer reviewers. Only 36 of the 304 submissions generated review comments recognizing any of the paper's scientific problems. And 16 of those papers were accepted by the editors despite the damning reviews.
The results show that Beall is good at spotting publishers with poor quality control: For the publishers on his list that completed the review process, 82% accepted the paper. Of course that also means that almost one in five on his list did the right thing—at least with my submission. A bigger surprise is that for DOAJ publishers that completed the review process, 45% accepted the bogus paper. "I find it hard to believe," says Bjørnshauge, the DOAJ founder. "We have been working with the community to draft new tighter criteria for inclusion." Beall, meanwhile, notes that in the year since this sting began, "the number of predatory publishers and predatory journals has continued to escalate at a rapid pace."
A striking picture emerges from the global distribution of open-access publishers, editors, and bank accounts. Most of the publishing operations cloak their true geographic location. They create journals with names like the American Journal of Medical and Dental Sciences or the European Journal of Chemistry to imitate—and in some cases, literally clone—those of Western academic publishers. But the locations revealed by IP addresses and bank invoices are continents away: Those two journals are published from Pakistan and Turkey, respectively, and both accepted the paper. The editor-in-chief of the European Journal of Chemistry, Hakan Arslan, a professor of chemistry at Mersin University in Turkey, does not see this as a failure of peer review but rather a breakdown in trust. When a paper is submitted, he writes in an e-mail, "We believe that your article is original and [all of] your supplied information is correct." The American Journal of Medical and Dental Sciences did not respond to e-mails.
About one-third of the journals targeted in this sting are based in India—overtly or as revealed by the location of editors and bank accounts—making it the world's largest base for open-access publishing; and among the India-based journals in my sample, 64 accepted the fatally flawed papers and only 15 rejected it. 26 rejections. (Explore a global wiring diagram of open-access publishing at http://scim.ag/OA-Sting (http://scim.ag/OA-Sting).)
But even when editors and bank accounts are in the developing world, the company that ultimately reaps the profits may be based in the United States or Europe. In some cases, academic publishing powerhouses sit at the top of the chain.
Journals published by Elsevier, Wolters Kluwer, and Sage all accepted my bogus paper. Wolters Kluwer Health, the division responsible for the Medknow journals, "is committed to rigorous adherence to the peer-review processes and policies that comply with the latest recommendations of the International Committee of Medical Journal Editors and the World Association of Medical Editors," a Wolters Kluwer representative states in an e-mail. "We have taken immediate action and closed down the Journal of Natural Pharmaceuticals."
In 2012, Sage was named the Independent Publishers Guild Academic and Professional Publisher of the Year. The Sage publication that accepted my bogus paper is the Journal of International Medical Research. Without asking for any changes to the paper's scientific content, the journal sent an acceptance letter and an invoice for $3100. "I take full responsibility for the fact that this spoof paper slipped through the editing process," writes Editor-in-Chief Malcolm Lader, a professor of pschopharmacology at King's College London and a fellow of the Royal Society of Psychiatrists, in an e-mail. He notes, however, that acceptance would not have guaranteed publication: "The publishers requested payment because the second phase, the technical editing, is detailed and expensive. … Papers can still be rejected at this stage if inconsistencies are not clarified to the satisfaction of the journal." Lader argues that this sting has a broader, detrimental effect as well. "An element of trust must necessarily exist in research including that carried out in disadvantaged countries," he writes. "Your activities here detract from that trust."
The Elsevier journal that accepted the paper, Drug Invention Today, is not actually owned by Elsevier, says Tom Reller, vice president for Elsevier global corporate relations: "We publish it for someone else." In an e-mail to Science, the person listed on the journal's website as editor-in-chief, Raghavendra Kulkarni, a professor of pharmacy at the BLDEA College of Pharmacy in Bijapur, India, stated that he has "not had access to [the] editorial process by Elsevier" since April, when the journal's owner "started working on [the] editorial process." "We apply a set of criteria to all journals before they are hosted on the Elsevier platform," Reller says. As a result of the sting, he says, "we will conduct another review."
The editor-in-chief of the Kobe Journal of Medical Sciences, Shun-ichi Nakamura, a professor of medicine at Kobe University in Japan, did not respond to e-mails. But his assistant, Reiko Kharbas, writes that "Upon receiving the letter of acceptance, Dr. Obalanefah withdrew the paper," referring to the standard final e-mail I sent to journals that accepted the paper. "Therefore, the letter of acceptance we have sent … has no effect whatsoever."
Other publishers are glad to have dodged the bullet. "It is a relief to know that our system is working," says Paul Peters, chief strategy officer of Hindawi, an open-access publisher in Cairo. Hindawi is an enormous operation: a 1000-strong editorial staff handling more than 25,000 articles per year from 559 journals. When Hindawi began expanding into open-access publishing in 2004, Peters admits, "we looked amateurish." But since then, he says, "publication ethics" has been their mantra. Peer reviewers at one Hindawi journal, Chemotherapy Research and Practice, rejected my paper after identifying its glaring faults. An editor recommended I try another Hindawi journal, ISRN Oncology; it, too, rejected my submission.
   Coda From the start of this sting, I have conferred with a small group of scientists who care deeply about open access. Some say that the open-access model itself is not to blame for the poor quality control revealed by Science's investigation. If I had targeted traditional, subscription-based journals, Roos told me, "I strongly suspect you would get the same result."* But open access has multiplied that underclass of journals, and the number of papers they publish. "Everyone agrees that open-access is a good thing," Roos says. "The question is how to achieve it."
The most basic obligation of a scientific journal is to perform peer review, arXiv founder Ginsparg says. He laments that a large proportion of open-access scientific publishers "clearly are not doing that." Ensuring that journals honor their obligation is a challenge that the scientific community must rise to. "Journals without quality control are destructive, especially for developing world countries where governments and universities are filling up with people with bogus scientific credentials," Ginsparg says.
As for the publisher that got Aline Noutcha to pony up a publication fee, the IP addresses in the e-mails from Scientific & Academic Publishing reveal that the operation is based in China, and the invoice they sent me asked for a direct transfer of $200 to a Hong Kong bank account.
The invoice arrived with good news: After a science-free review process, one of their journals—the International Journal of Cancer and Tumor—accepted the paper. Posing as lead author Alimo Atoa, I requested that it be withdrawn. I received a final message that reads like a surreal love letter from one fictional character to another:
Dear Alimo Atoa,
We fully respect your choice and withdraw your artilce.
If you are ready to publish your paper,please let me know and i will be at your service at any time.
Sincerely yours, Grace Groovy
* Correction on 3 Oct. 2013: This sentence was clarified to better reflect Roos's view.
 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 05-10-2013, 08:57:35
Toliko o naučnim publikacijama i rejtingu. Međutim, stvarnost je daleko komplikovanija. Toliko da se i ponuđeni link mora smatrati provokacijom, a ne informacijom.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 05-10-2013, 10:55:20
Provo.. kacijom???  :shock: :shock:
 
Dobro, ajde.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 05-10-2013, 11:08:21
Link je provokacija, a ne tvoja ponuda.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Father Jape on 06-10-2013, 08:10:14
Evo na jednom mestu više odgovora i diskusija koje je ovo što Meho posla provociralo:

http://languagelog.ldc.upenn.edu/nll/?p=7584 (http://languagelog.ldc.upenn.edu/nll/?p=7584)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 06-10-2013, 08:28:17

...
Samo sam valjda skloniji tome da je bitno i da se čuju lupetanja jer onda znaš šta ljudi misle i kako da nekom drugom prilikom formulišeš svoje teze itd.


Tu se (i zbog toga) ne nalazimo: sa principom se ne samo slažem, nego ga i primenjujem, koliko je u mojoj skromnoj moći. Ali fokus je ovde na očuvanju diskursa, a taj fokus nameće primat lateralnosti. Nije problem razgovarati sa čovekom koji naprosto zastupa drugačije mišljenje, to bazirano na specifičnostima perspektive i interesa; ako išta, to je izazov upravo vredan komunikacije, kao što se i iz priloženog jasno vidi.  :wink:  Ali lateralni minimum je neophodan, to kako u informisanosti, tako i zrelosti sagovornika. U tom slučaju, mi ne možemo više da govorimo o "lupetanjima", nego o neophodnoj različitosti stavova, koja je upravo baza suvisle razmene, a time i preduslov svake sadržajne konverzacije. "Lupetanje", s druge strane, nema tu lateralnu privilegiju, pa se stoga i ne može (ne sme, dodala bih, čisto preciznosti radi) uvažavati kao kredibilan ritort, to bar gledano iz perspektive očuvanja diskursa.


Ili, da uprostim: možeš se ti sa budalom natezati do sudnjeg dana u podne, ali on iz te konverzacije neće izaći ništa pametniji, dok ćeš ti izaći ili gluplji ili umorniji. Trećeg ishoda ja tu ne vidim, ako isključimo zabavni aspekt kao takav.


No, naravno, to je samo moje lično mišljenje, koje ti ne namećem (to bar ne sada i ne ovde, za ostatak mog obraćanja priznajem da često ima maliciozni aspekt, no to je upravo rezultat gore navedenih procena, tako da tu nema pomoći ni meni, a kamoli tebi), naravno, nego ga samo podrobnije objašnjavam, to u svrhu potpunijeg razumevanja. 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 06-10-2013, 08:36:50
Razumem i uvažavam, no vraćam se na priču da govorimo o publikacijama koje popularišu nauku, pa mislim da je korisno da znaju i kad deo njihovog čitalaštva lupeta jer se onda popularisanje može dizajnirati tako da preemptivno odgovori na lupetanje, itd.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 06-10-2013, 08:41:54
Budalama ne treba popularizovati nauku, nego kondome.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 06-10-2013, 08:43:40
 :lol: :lol: :lol: :lol:  Pričaš o mom dayjobu.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 06-10-2013, 08:48:15
Pa zašto onda na forumu rasplićeš ta dobročinstva zbog kojih ti je mesto u raju već bukirano?  :mrgreen:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 06-10-2013, 08:53:09
Mogu smo da citiram pokojnog Davora Bobića: U raju je lepo, al' u paklu je ekipa.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 06-10-2013, 08:59:02
 :lol: :lol: :lol:  a dobro onda, sad me znatno manje grize savest što tako često na prsa primaš one for the tim.  :evil:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: angel011 on 06-10-2013, 13:03:59
Budalama ne treba popularizovati nauku, nego kondome.


 xrofl


Ili sterilizaciju?  :lol:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 06-10-2013, 13:16:28
I mačke sterilišemo iz potrebe, iako ih volimo. Ako živo biće ne može samo da se ponaša u skladu sa svojom okolinom i svojim mogućnostima, onda okolina mora da se brani.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Josephine on 06-10-2013, 13:36:38
Elita.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 06-10-2013, 14:10:21
Dobro, od preporuke korišćenja kontracepcije do nasilne sterilizacije je ipak korak pogolem, nemojmo ih poistovećivati.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 12-10-2013, 09:24:20
Evo daljih čudesa na temu "slabog merenja" odnosno takvog posmatranja kvantnog sistema da posmatrač ne poremeti isti:
 Physicists snatch a peep into quantum paradox (http://www.nature.com/news/physicists-snatch-a-peep-into-quantum-paradox-1.13899)
Quote
Measurement-induced collapse of quantum wavefunction captured in slow motion.
 
 
It is the most fundamental, and yet also the strangest postulate of the theory of quantum mechanics: the idea that a quantum system will catastrophically collapse from a blend of several possible quantum states to just one the moment it is measured by an experimentalist.
 
In textbooks on quantum mechanics, the collapse is depicted as sudden and irreversible. It is also extremely counterintuitive. Researchers have struggled to understand how a measurement can profoundly alter the state that an object is in, rather than just allowing us to learn about an objective reality.
                                                            
A new experiment1 (http://www.nature.com/news/physicists-snatch-a-peep-into-quantum-paradox-1.13899#b1)sheds some light on this question through the use of weak measurements — indirect probes of quantum systems that tweak a wavefunction slightly while providing partial information about its state, avoiding a sudden collapse.
                                                            
Atomic and solid-state physicist Kater Murch of the University of California, Berkeley, and his colleagues performed a series of weak measurements on a superconducting circuit that was in a superposition — a combination of two quantum states. They did this by monitoring microwaves that had passed through a box containing the circuit, based on the fact that the circuit's electrical oscillations alter the state of the microwaves as they pass through the box. Over a couple of microseconds, those weak measurements captured snapshots of the state of the circuit as it gradually changed from a superposition to just one of the states within that superposition — as if charting the collapse of a quantum wavefunction in slow motion.
                                                            
Although equivalent experiments have been done on the quantum states of photons of light, this is the first time such work has been done in a typically noisier solid-state system. “It demonstrates how much progress we’ve made in the solid state in the past 10 years,” says Murch. “Finally, systems are so pure that we can rival experiments in photons.”
                                                            Slow-motion movie                                                            
The team also found that decoherence, the process by which noise in the environment causes quantum states to decay, can be minimized by repeated weak measurements. Murch says that the microwaves used to probe the superconducting circuit can be thought of as its environment because they are the predominant thing interacting with it. By monitoring the environment, the fluctuations in the microwaves become a known quantity rather than a source of unknown noise.
 
 That enables the quantum state to remain pure, as Murch and his demonstrated — a finding that has a practical consequence. Quantum bits used for computation can be encoded in the state of a superconducting circuit, as they were in the present experiment, but they can also be made from the quantum state of a trapped ion or of an impurity in a crystal. Being able to sustain the coherence of a quantum bit in a solid-state system by making weak measurements ought to be possible in other experimental hardware too. “It’s a very general idea,” says quantum theorist Andrew Jordan at the University of Rochester, New York.
Theorist Alexander Korotkov of the University of California, Riverside, adds that the measurements can be thought of as a kind of 'quantum steering' that helps to keep the system evolving along a quantum path, casting light on the intrinsically gradual nature of any measurement process. "In real life nothing happens instantaneously,” he says.
   Nature doi:10.1038/nature.2013.13899 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 20-10-2013, 07:56:53
... a evo i tačke, samo ne znam da li je stavljena na rečenicu ili na "i"...  :lol:





http://www.laboratoryequipment.com/news/2013/10/physicists-prove-heisenberg-right (http://www.laboratoryequipment.com/news/2013/10/physicists-prove-heisenberg-right)




Physicists Prove Heisenberg Right





Fri, 10/18/2013 - 7:00am[
(http://www.laboratoryequipment.com/sites/laboratoryequipment.com/files/styles/large/public/101813_heisenberg.jpg?itok=qiuu3l2P)




An international team of scientists has provided proof of a key feature of quantum physics – Heisenberg's error-disturbance relation — more than 80 years after it was first suggested.

One of the basic concepts in the world of quantum mechanics is that it is impossible to observe physical objects without affecting them in a significant way; there can be no measurement without disturbance.
In a paper in 1927, Werner Heisenberg, one of the architects of the fundamental theories of modern physics, claimed that this fact could be expressed as an uncertainty relation, describing a reciprocal relation between the accuracy in position and the disturbance in momentum. However, he did not supply any evidence for the theory which was largely based on intuition.


Now Prof. Paul Busch of the Univ. of York, Prof. Pekka Lahti of the Univ. of Turku, Finland and Prof. Reinhard Werner of Leibniz Universität Hannover, Germany have finally provided a precise formulation and proof of the error-disturbance relation in an article published today in the journal Physical Review Letters.


Their work has important implications for the developing field of quantum cryptography and computing, as it reaffirms that quantum-encrypted messages can be transmitted securely since an eavesdropper would necessarily disturb the system carrying the message and this could be detected.


Busch, from York's Department of Mathematics, says, "While the slogan 'no measurement without disturbance' has established itself under the name Heisenberg effect in the consciousness of the scientifically interested public, a precise statement of this fundamental feature of the quantum world has remained elusive, and serious attempts at rigorous formulations of it as a consequence of quantum theory have led to seemingly conflicting preliminary results.


"We have shown that despite recent claims to the contrary, Heisenberg-type inequalities can be proven that describe a trade-off between the precision of a position measurement and the necessary resulting disturbance of momentum and vice-versa."


The research involved the scientists considering how simultaneous measurements of a particle's position and momentum are calibrated. They defined the errors in these measurements as the spreads in the distributions of the outcomes in situations where either the position or the momentum of the particle is well defined. They found that these errors for combined position and momentum measurements obey Heisenberg's principle.


Werner says, "Since I was a student I have been wondering what could be meant by an 'uncontrollable' disturbance of momentum in Heisenberg's Gedanken experiment. In our theorem this is now clear: not only does the momentum change, there is also no way to retrieve it from the post measurement state."


Lahti adds, "It is impressive to witness how the intuitions of the great masters from the very early stage of the development of the then brand new theory turn out to be true."
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 21-10-2013, 09:06:32
nego, posto smo na ovaj topik vec stavljali aktuelne kontroverze po pitanju popularizacije nauke i kojecega, evo jos jedne kontroverze koja polarizuje laicki a bogami i naucni domen jednako:
 
 
(http://www.slate.com/content/dam/slate/articles/health_and_science/new_scientist/2013/10/131018_NEWSCI_GoldenRiceInventor.jpg.CROP.original-original.jpg)
 
 
 
Photo by Erik de Castro/Reuters
 Ingo Potrykus (http://www.goldenrice.org/Content1-Who/who_Ingo.php) is a co-inventor of golden rice (http://www.goldenrice.org/index.php), which is genetically engineered to combat blindness and death in children (http://www.who.int/nutrition/topics/vad/en/index.html) by supplying 60 percent of the vitamin A they need in a typical daily helping of rice. His project has been opposed from the outset by environmental groups.Andy Coghlan: Why did you develop golden rice?
Ingo Potrykus: I got involved because I'm concerned about food security. I realized it's not just about calories, but also about the quality of food. I started working on it in the early 1990s with Peter Beyer (http://www.bioss.uni-freiburg.de/cms/92.html). We started on the problem of iron deficiency, but that work didn't pan out, so we switched to tackling vitamin A deficiency.By 1999 we had solved the problem (http://www.sciencemag.org/content/287/5451/303.abstract?sid=4846b67d-5c56-4daf-b02f-22473571f0c1). It was a surprise it worked because from the outset it looked totally crazy.                          Advertisement
  AC: But environmental groups, including Greenpeace, opposed it?
IP: They were against it from the beginning. They said it was fool's gold because children would need to eat several kilograms of it to get their daily requirement (http://www.newscientist.com/article/dn408-moral-maze.html). Children only eat around 300 to 400 grams a day. We worked out that Greenpeace wasn’t right, and that the rice contained enough to meet children's needs, but we couldn't prove that because we didn't then have data from an actual trial.One of the cleverest tricks of the anti-GMO movement is to link GMOs so closely to Monsanto. AC: That didn't kill off the project, though?
IP: Indeed no. The next big step was in 2005 when a group at biotech company Syngenta replaced one of the genes intended to produce beta carotene. The original gene, which makes an enzyme called phytoene synthase, came from the narcissus flower, and they replaced it with one from maize that is far more efficient. It produced 20 times more beta carotene (http://www.newscientist.com/article/dn7196-new-golden-rice-carries-far-more-vitamin.html), the molecule from carrots that combines with a second molecule of itself once inside our bodies to make a molecule of vitamin A. It was a big success.But again, we couldn't prove we had enough to meet children's needs, so the Greenpeace myth about golden rice being useless lived on. They continued to say that the problem was solvable by other means.AC: Do they have a point? Why couldn't children just be given vitamin A capsules, or other foods that contain it?
IP: The capsules are already being given through programs of the World Health Organization (http://www.who.int/vmnis/vitamina/en/) and charities such as Helen Keller International (http://www.hki.org/reducing-malnutrition/vitamin-a-supplementation/). They've been running the programs for 15 years, but they cost tens of millions of dollars a year. The problem is that besides the expense, you need the infrastructure to distribute the capsules. We're aiming for people who can't be reached this way, poor farmers in remote places.As for the possibility of eating foods that supply vitamin A, such as liver, leafy green vegetables, and eggs, the people we're targeting are too poor to buy them. Some kitchen garden projects provide them, but despite these interventions we still have 6,000 children dying every day. These are not enough. Our aim is to complement, not replace, these programs.AC: There's a project in Uganda and Mozambique (http://www.newscientist.com/article/mg21528784.200-nutrientboosted-foods-protect-against-blindness.html) to combat vitamin A deficiency by supplying sweet potatoes conventionally bred to contain extra beta carotene. Over two years it doubled vitamin A intake in women and children (http://www.harvestplus.org/content/uganda-and-mozambique) compared with those who ate conventional sweet potatoes. Could this be done with rice?
IP: Sweet potatoes naturally contain beta carotene, so you can use traditional breeding to improve the content. Rice contains no beta carotene, so it's impossible to introduce it without genetic engineering. Because the sweet potato project does not involve genetic modification, Greenpeace doesn't complain about it despite the aim being identical to ours. But the experience with sweet potatoes shows that what we're trying to achieve with rice is realistic. As soon as people get the potatoes, it improves their vitamin A status.AC: So where has the project got to now?
IP: It took a long time, but by conventional breeding we bred our new golden rice with varieties to suit individual tastes in different countries. This is now completed in the Philippines, Indonesia, India, China, Vietnam, and elsewhere in Asia.AC: Is it always golden, and what does it taste like?
IP: It always has a beautiful yellow color, and it tastes just the same as usual. Because it's an integral part of the data needed to satisfy regulation authorities, professional taste panels have also tested it.


 
ostatak je ovde  (http://www.slate.com/articles/health_and_science/new_scientist/2013/10/golden_rice_inventor_ingo_potrykus_greenpeace_and_others_wicked_for_opposition.html)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 21-10-2013, 09:21:09
Treba se fokusirati na ovaj deo teksta:


Ingo Potrykus is a co-inventor of golden rice,

Pronalazači su skloni da budu i vlasnici i da eksploatišu svoje vlasništvo. Po svaku cenu.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 21-10-2013, 09:40:05
Pa, to se podrazumeva, a ja nalazim i da je to ne samo normalno, nego i u skladu sa generalnim zakonom o vlasnistvu: pronalazac jeste vlasnik patenta, ili je (u nekim slucajevima) vlasnik onaj ko mu je taj proces finansirao.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 21-10-2013, 09:48:17
Ne bih ja dalje o etici GMO proizvoda u okviru Hajzenberga.

Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 22-10-2013, 08:59:40
I The Economist ima šta da kaže na ime nauke koja je počela suviše da veruje, premalo da proverava:

How science goes wrong (http://www.economist.com/news/leaders/21588069-scientific-research-has-changed-world-now-it-needs-change-itself-how-science-goes-wrong)


Quote
Scientific research has changed the world. Now it needs to change itself



A SIMPLE idea underpins science: “trust, but verify”. Results should always be subject to challenge from experiment. That simple but powerful idea has generated a vast body of knowledge. Since its birth in the 17th century, modern science has changed the world beyond recognition, and overwhelmingly for the better.
But success can breed complacency. Modern scientists are doing too much trusting and not enough verifying—to the detriment of the whole of science, and of humanity.


Too many of the findings that fill the academic ether are the result of shoddy experiments or poor analysis (see article (http://www.economist.com/news/briefing/21588057-scientists-think-science-self-correcting-alarming-degree-it-not-trouble)). A rule of thumb among biotechnology venture-capitalists is that half of published research cannot be replicated. Even that may be optimistic. Last year researchers at one biotech firm, Amgen, found they could reproduce just six of 53 “landmark” studies in cancer research. Earlier, a group at Bayer, a drug company, managed to repeat just a quarter of 67 similarly important papers. A leading computer scientist frets that three-quarters of papers in his subfield are bunk. In 2000-10 roughly 80,000 patients took part in clinical trials based on research that was later retracted because of mistakes or improprieties.
What a load of rubbish
Even when flawed research does not put people’s lives at risk—and much of it is too far from the market to do so—it squanders money and the efforts of some of the world’s best minds. The opportunity costs of stymied progress are hard to quantify, but they are likely to be vast. And they could be rising.
One reason is the competitiveness of science. In the 1950s, when modern academic research took shape after its successes in the second world war, it was still a rarefied pastime. The entire club of scientists numbered a few hundred thousand. As their ranks have swelled, to 6m-7m active researchers on the latest reckoning, scientists have lost their taste for self-policing and quality control. The obligation to “publish or perish” has come to rule over academic life. Competition for jobs is cut-throat. Full professors in America earned on average $135,000 in 2012—more than judges did. Every year six freshly minted PhDs vie for every academic post. Nowadays verification (the replication of other people’s results) does little to advance a researcher’s career. And without verification, dubious findings live on to mislead.
Careerism also encourages exaggeration and the cherry-picking of results. In order to safeguard their exclusivity, the leading journals impose high rejection rates: in excess of 90% of submitted manuscripts. The most striking findings have the greatest chance of making it onto the page. Little wonder that one in three researchers knows of a colleague who has pepped up a paper by, say, excluding inconvenient data from results “based on a gut feeling”. And as more research teams around the world work on a problem, the odds shorten that at least one will fall prey to an honest confusion between the sweet signal of a genuine discovery and a freak of the statistical noise. Such spurious correlations are often recorded in journals eager for startling papers. If they touch on drinking wine, going senile or letting children play video games, they may well command the front pages of newspapers, too.
Conversely, failures to prove a hypothesis are rarely even offered for publication, let alone accepted. “Negative results” now account for only 14% of published papers, down from 30% in 1990. Yet knowing what is false is as important to science as knowing what is true. The failure to report failures means that researchers waste money and effort exploring blind alleys already investigated by other scientists.
The hallowed process of peer review is not all it is cracked up to be, either. When a prominent medical journal ran research past other experts in the field, it found that most of the reviewers failed to spot mistakes it had deliberately inserted into papers, even after being told they were being tested.
If it’s broke, fix it
All this makes a shaky foundation for an enterprise dedicated to discovering the truth about the world. What might be done to shore it up? One priority should be for all disciplines to follow the example of those that have done most to tighten standards. A start would be getting to grips with statistics, especially in the growing number of fields that sift through untold oodles of data looking for patterns. Geneticists have done this, and turned an early torrent of specious results from genome sequencing into a trickle of truly significant ones.
Ideally, research protocols should be registered in advance and monitored in virtual notebooks. This would curb the temptation to fiddle with the experiment’s design midstream so as to make the results look more substantial than they are. (It is already meant to happen in clinical trials of drugs, but compliance is patchy.) Where possible, trial data also should be open for other researchers to inspect and test.


The most enlightened journals are already becoming less averse to humdrum papers. Some government funding agencies, including America’s National Institutes of Health, which dish out $30 billion on research each year, are working out how best to encourage replication. And growing numbers of scientists, especially young ones, understand statistics. But these trends need to go much further. Journals should allocate space for “uninteresting” work, and grant-givers should set aside money to pay for it. Peer review should be tightened—or perhaps dispensed with altogether, in favour of post-publication evaluation in the form of appended comments. That system has worked well in recent years in physics and mathematics. Lastly, policymakers should ensure that institutions using public money also respect the rules.
Science still commands enormous—if sometimes bemused—respect. But its privileged status is founded on the capacity to be right most of the time and to correct its mistakes when it gets things wrong. And it is not as if the universe is short of genuine mysteries to keep generations of scientists hard at work. The false trails laid down by shoddy research are an unforgivable barrier to understanding.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 23-10-2013, 07:48:18


Quote
And it is not as if the universe is short of genuine mysteries to keep generations of scientists hard at work. The false trails laid down by shoddy research are an unforgivable barrier to understanding.
Word.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: PTY on 28-10-2013, 13:57:54
i jos: http://www.latimes.com/business/la-fi-hiltzik-20131027,0,1228881.column#axzz2iwz1aoLh (http://www.latimes.com/business/la-fi-hiltzik-20131027,0,1228881.column#axzz2iwz1aoLh)



Quote

Science has lost its way, at a big cost to humanity



Researchers are rewarded for splashy findings, not for double-checking accuracy. So many scientists looking for cures to diseases have been building on ideas that aren't even true.

In today's world, brimful as it is with opinion and falsehoods masquerading as facts, you'd think the one place you can depend on for verifiable facts is science.

You'd be wrong. Many billions of dollars' worth of wrong.

A few years ago, scientists at the Thousand Oaks biotech firm Amgen set out to double-check the results of 53 landmark papers in their fields of cancer research and blood biology.

The idea was to make sure that research on which Amgen was spending millions of development dollars still held up. They figured that a few of the studies would fail the test — that the original results couldn't be reproduced because the findings were especially novel or described fresh therapeutic approaches.

But what they found was startling: Of the 53 landmark papers, only six could be proved valid.

"Even knowing the limitations of preclinical research," observed C. Glenn Begley, then Amgen's head of global cancer research, "this was a shocking result."

Unfortunately, it wasn't unique. A group at Bayer HealthCare in Germany similarly found that only 25% of published papers on which it was basing R&D projects could be validated, suggesting that projects in which the firm had sunk huge resources should be abandoned. Whole fields of research, including some in which patients were already participating in clinical trials, are based on science that hasn't been, and possibly can't be, validated.

"The thing that should scare people is that so many of these important published studies turn out to be wrong when they're investigated further," says Michael Eisen, a biologist at UC Berkeley and the Howard Hughes Medical Institute. The Economist recently estimated spending on biomedical R&D in industrialized countries at $59 billion a year. That's how much could be at risk from faulty fundamental research.

Eisen says the more important flaw in the publication model is that the drive to land a paper in a top journal — Nature and Science lead the list — encourages researchers to hype their results, especially in the life sciences. Peer review, in which a paper is checked out by eminent scientists before publication, isn't a safeguard. Eisen says the unpaid reviewers seldom have the time or inclination to examine a study enough to unearth errors or flaws.

"The journals want the papers that make the sexiest claims," he says. "And scientists believe that the way you succeed is having splashy papers in Science or Nature — it's not bad for them if a paper turns out to be wrong, if it's gotten a lot of attention."

Eisen is a pioneer in open-access scientific publishing, which aims to overturn the traditional model in which leading journals pay nothing for papers often based on publicly funded research, then charge enormous subscription fees to universities and researchers to read them.

But concern about what is emerging as a crisis in science extends beyond the open-access movement. It's reached the National Institutes of Health, which last week launched a project to remake its researchers' approach to publication. Its new PubMed Commons system allows qualified scientists to post ongoing comments about published papers. The goal is to wean scientists from the idea that a cursory, one-time peer review is enough to validate a research study, and substitute a process of continuing scrutiny, so that poor research can be identified quickly and good research can be picked out of the crowd and find a wider audience.

PubMed Commons is an effort to counteract the "perverse incentives" in scientific research and publishing, says David J. Lipman, director of NIH's National Center for Biotechnology Information, which is sponsoring the venture.

The Commons is currently in its pilot phase, during which only registered users among the cadre of researchers whose work appears in PubMed — NCBI's clearinghouse for citations from biomedical journals and online sources — can post comments and read them. Once the full system is launched, possibly within weeks, commenters still will have to be members of that select group, but the comments will be public.

Science and Nature both acknowledge that peer review is imperfect. Science's executive editor, Monica Bradford, told me by email that her journal, which is published by the American Assn. for the Advancement of Science, understands that for papers based on large volumes of statistical data — where cherry-picking or flawed interpretation can contribute to erroneous conclusions — "increased vigilance is required." Nature says that it now commissions expert statisticians to examine data in some papers.

But they both defend pre-publication peer review as an essential element in the scientific process — a "reasonable and fair" process, Bradford says.

Yet there's been some push-back by the prestige journals against the idea that they're encouraging flawed work — and that their business model amounts to profiteering. Earlier this month, Science published a piece by journalist John Bohannon about what happened when he sent a spoof paper with flaws that could have been noticed by a high school chemistry student to 304 open-access chemistry journals (those that charge researchers to publish their papers, but make them available for free). It was accepted by more than half of them.

One that didn't bite was PloS One, an online open-access journal sponsored by the Public Library of Science, which Eisen co-founded. In fact, PloS One was among the few journals that identified the fake paper's methodological and ethical flaws.

What was curious, however, was that although Bohannon asserted that his sting showed how the open-access movement was part of "an emerging Wild West in academic publishing," it was the traditionalist Science that published the most dubious recent academic paper of all.

This was a 2010 paper by then-NASA biochemist Felisa Wolfe-Simon and colleagues claiming that they had found bacteria growing in Mono Lake that were uniquely able to subsist on arsenic and even used arsenic to build the backbone of their DNA.

The publication in Science was accompanied by a breathless press release and press conference sponsored by NASA, which had an institutional interest in promoting the idea of alternative life forms. But almost immediately it was debunked by other scientists for spectacularly poor methodology and an invalid conclusion. Wolfe-Simon, who didn't respond to a request for comment last week, has defended her interpretation of her results as "viable." She hasn't withdrawn the paper, nor has Science, which has published numerous critiques of the work. Wolfe-Simon is now associated with the prestigious Lawrence Berkeley National Laboratory.

To Eisen, the Wolfe-Simon affair represents the "perfect storm of scientists obsessed with making a big splash and issuing press releases" — the natural outcome of a system in which there's no career gain in trying to replicate and validate previous work, as important as that process is for the advancement of science.

"A paper that actually shows a previous paper is true would never get published in an important journal," he says, "and it would be almost impossible to get that work funded."

However, the real threat to research and development doesn't come from one-time events like the arsenic study, but from the dissemination of findings that look plausible on the surface but don't stand up to scrutiny, as Begley and his Amgen colleagues found.

The demand for sexy results, combined with indifferent follow-up, means that billions of dollars in worldwide resources devoted to finding and developing remedies for the diseases that afflict us all is being thrown down a rathole. NIH and the rest of the scientific community are just now waking up to the realization that science has lost its way, and it may take years to get back on the right path.

Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 09-12-2013, 10:06:28
Dalje na slične teme. Peter Higgs, koga sigurno pamtimo po takvim hitovima kao što je Higsov bozon, u Guardianu veli da ne veruje da bi njega danas ijedan univerzitet zaposlio jer nije (nikad bio) dovoljno produktivan po današnjim merilima. On smatra da se danas, zbog, jelte, manje-više tržišnog pristupa akademizmu, od naučnika očekuje da objavljuju mnogo radova a da to onda njemu ne bi nikad dalo dovoljno vremena da se zaista pošteno posveti određenoj temi. Veli i da bi ga njegov univerzitet verovatno otpustio 1980. godine, zbog niske produktivnosti, da nije bio nominovan za Nobelovu nagradu...

Peter Higgs: I wouldn't be productive enough for today's academic system (http://www.theguardian.com/science/2013/dec/06/peter-higgs-boson-academic-system)



Quote

  Peter Higgs (http://www.theguardian.com/science/peterhiggs), the British physicist who gave his name to the Higgs boson (http://www.theguardian.com/science/higgs-boson), believes no university would employ him in today's academic system because he would not be considered "productive" enough.
The emeritus professor at Edinburgh University, who says he has never sent an email, browsed the internet or even made a mobile phone call, published fewer than 10 papers after his groundbreaking work, which identified the mechanism by which subatomic material acquires mass, was published in 1964.
He doubts a similar breakthrough could be achieved in today's academic culture, because of the expectations on academics to collaborate and keep churning out papers. He said: "It's difficult to imagine how I would ever have enough peace and quiet in the present sort of climate to do what I did in 1964."
Speaking to the Guardian en route to Stockholm to receive the 2013 Nobel prize for science, Higgs, 84, said he would almost certainly have been sacked had he not been nominated for the Nobel in 1980.
Edinburgh University's authorities then took the view, he later learned, that he "might get a Nobel prize – and if he doesn't we can always get rid of him".
Higgs said he became "an embarrassment to the department when they did research assessment exercises". A message would go around the department saying: "Please give a list of your recent publications." Higgs said: "I would send back a statement: 'None.' "
By the time he retired in 1996, he was uncomfortable with the new academic culture. "After I retired it was quite a long time before I went back to my department. I thought I was well out of it. It wasn't my way of doing things any more. Today I wouldn't get an academic job. It's as simple as that. I don't think I would be regarded as productive enough."
Higgs revealed that his career had also been jeopardised by his disagreements in the 1960s and 70s with the then principal, Michael Swann, who went on to chair the BBC. Higgs objected to Swann's handling of student protests and to the university's shareholdings in South African companies during the apartheid regime. "[Swann] didn't understand the issues, and denounced the student leaders."
He regrets that the particle he identified in 1964 became known as the "God particle".
He said: "Some people get confused between the science and the theology. They claim that what happened at Cern (http://www.theguardian.com/science/cern) proves the existence of God."
An atheist since the age of 10, he fears the nickname "reinforces confused thinking in the heads of people who are already thinking in a confused way. If they believe that story about creation in seven days, are they being intelligent?"
He also revealed that he turned down a knighthood in 1999. "I'm rather cynical about the way the honours system is used, frankly. A whole lot of the honours system is used for political purposes by the government in power."
He has not yet decided which way he will vote in the referendum on Scottish independence (http://www.theguardian.com/politics/scottish-independence). "My attitude would depend a little bit on how much progress the lunatic right of the Conservative party makes in trying to get us out of Europe (http://www.theguardian.com/world/europe-news). If the UK were threatening to withdraw from Europe, I would certainly want Scotland (http://www.theguardian.com/uk/scotland) to be out of that."
He has never been tempted to buy a television, but was persuaded to watch The Big Bang Theory last year, and said he wasn't impressed.
 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 09-12-2013, 10:38:06
Ha, evo mi ga istomišljenik. Bogme, ja skoro ko Kepler. Kao priznanje posvećujem Higsu svoju kratku radioničku priču: "Pisac nepoznatog dela i Higsov bozon".
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: tomat on 12-12-2013, 22:55:43
Simulations back up theory that Universe is a hologram


A ten-dimensional theory of gravity makes the same predictions as standard quantum physics in fewer dimensions.[/color][/font][/size]
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[/font][/color][/size][/color]
Quote
[/size]A team of physicists has provided some of the clearest evidence yet that our Universe could be just one big projection.[/color]
[/size]
[/color][/size]In 1997, theoretical physicist Juan Maldacena proposed1 (http://www.nature.com/news/simulations-back-up-theory-that-universe-is-a-hologram-1.14328#b1)[/size] that an audacious model of the Universe in which gravity arises from infinitesimally thin, vibrating strings could be reinterpreted in terms of well-established physics. The mathematically intricate world of strings, which exist in nine dimensions of space plus one of time, would be merely a hologram: the real action would play out in a simpler, flatter cosmos where there is no gravity.[/size]Maldacena's idea thrilled physicists because it offered a way to put the popular but still unproven theory of strings on solid footing — and because it solved apparent inconsistencies between quantum physics and Einstein's theory of gravity. It provided physicists with a mathematical Rosetta stone, a 'duality', that allowed them to translate back and forth between the two languages, and solve problems in one model that seemed intractable in the other and vice versa. But although the validity of Maldacena's ideas has pretty much been taken for granted ever since, a rigorous proof has been elusive.[/color]
In two papers posted on the arXiv repository, Yoshifumi Hyakutake of Ibaraki University in Japan and his colleagues now provide, if not an actual proof, at least compelling evidence that Maldacena’s conjecture is true.
In one paper[/size]2 (http://www.nature.com/news/simulations-back-up-theory-that-universe-is-a-hologram-1.14328#b2)[/size], Hyakutake computes the internal energy of a black hole, the position of its event horizon (the boundary between the black hole and the rest of the Universe), its entropy and other properties based on the predictions of string theory as well as the effects of so-called virtual particles that continuously pop into and out of existence. In the other3 (http://www.nature.com/news/simulations-back-up-theory-that-universe-is-a-hologram-1.14328#b3)[/size], he and his collaborators calculate the internal energy of the corresponding lower-dimensional cosmos with no gravity. The two computer calculations match.
“It seems to be a correct computation,” says Maldacena, who is now at the Institute for Advanced Study in Princeton, New Jersey and who did not contribute to the team's work.
Regime changeThe findings “are an interesting way to test many ideas in quantum gravity and string theory”, Maldacena adds. The two papers, he notes, are the culmination of a series of articles contributed by the Japanese team over the past few years. “The whole sequence of papers is very nice because it tests the dual [nature of the universes] in regimes where there are no analytic tests.”
“They have numerically confirmed, perhaps for the first time, something we were fairly sure had to be true, but was still a conjecture — namely that the thermodynamics of certain black holes can be reproduced from a lower-dimensional universe,” says Leonard Susskind, a theoretical physicist at Stanford University in California who was among the first theoreticians to explore the idea of holographic universes.
Neither of the model universes explored by the Japanese team resembles our own, Maldacena notes. The cosmos with a black hole has ten dimensions, with eight of them forming an eight-dimensional sphere. The lower-dimensional, gravity-free one has but a single dimension, and its menagerie of quantum particles resembles a group of idealized springs, or harmonic oscillators, attached to one another.
Nevertheless, says Maldacena, the numerical proof that these two seemingly disparate worlds are actually identical gives hope that the gravitational properties of our Universe can one day be explained by a simpler cosmos purely in terms of quantum theory.Nature doi:10.1038/nature.2013.14328
[/size][size=78%][[/size][/size][/color]/[/font][/color][/size][size=78%]quote][/size]
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[/size]http://www.nature.com/news/simulations-back-up-theory-that-universe-is-a-hologram-1.14328[size=78%]

edit: nešto se ovo kopipejstovanje zakomplikovalo, vidi kakav haos je ispao. nije ovo bilo ovako ranije.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 23-02-2014, 09:00:51
Sto se tice bakterija, jako mi je tesko, ali moram da stanem na kuferovu stranu...
Ja sam svoje rodjene sjebao, verovatno antibioticima, i sada imam puno problema...


U poslednjem broju Economista ima dobar clanak o tome...


[size=78%]http://www.economist.com/node/21560523 (http://www.economist.com/node/21560523)[/size]




Super članak!


Evo još malo o bakterijama koje nam (možda) utiču na kognitivne procese:


Body bacteria: Can your gut bugs make you smarter? (http://www.bbc.com/future/story/20140221-can-gut-bugs-make-you-smarter)
 
Quote
The bacteria in our guts can influence the working of the mind, says Frank Swain. So could they be upgraded to enhance brainpower?   
 
I have some startling news: you are not human. At least, by some counts. While you are indeed made up of billions of human cells working in remarkable concert, these are easily outnumbered by the bacterial cells that live on and in you (http://www.bbc.com/future/story/20120412-the-beasts-inside-you) – your microbiome. There are ten of them for every one of your own cells, and they add an extra two kilograms (4.4lbs) to your body.
Far from being freeloading passengers, many of these microbes actively help digest food and prevent infection. And now evidence is emerging that these tiny organisms may also have a profound impact on the brain too. They are a living augmentation of your body – and like any enhancement, this means they could, in principle, be upgraded. So, could you hack your microbiome to make yourself healthier, happier, and smarter too?
According to John Cryan, this isn’t as far-fetched as it sounds. As a professor of anatomy and neuroscience at University College Cork, he specialises in the relationship between the brain and the gut. One of his early experiments showed the diversity of bacteria living in the gut was greatly diminished in mice suffering from early life stress. This finding inspired him to investigate the connection between the microbiome and the brain.
The bacterial microbiota in the gut helps normal brain development, says Cryan. “If you don’t have microbiota you have major changes in brain structure and function, and then also in behaviour.” In a pioneering study, a Japanese research team showed that mice raised without any gut bacteria had an exaggerated physical response to stress, releasing more hormone than mice that had a full complement of bacteria. However, this effect could be reduced in bacteria-free mice by repopulating their gut with Bifidobacterium infantis, one of the major symbiotic bacteria found in the gut. Cryan’s team built on this finding, showing that this effect could be reproduced even in healthy mice. “We took healthy mice and fed them Lactobacillus [another common gut bacteria), and we showed that these animals had a reduced stress response and reduced anxiety-related behaviours.”
 
But why should bacteria in the gut affect the brain? There are several different ways that messages can be sent from one organ to the other. It can be hormones or immune cells via the bloodstream, or by impulses along the vagus nerve, which stretches from the brain to intertwine closely with the gut. Through these pathways, actions in one produce effects in the other.
So how might you go about altering your microbiome to do a spot of brain-hacking? Cryan’s team works on several fronts, investigating the potential to manage stress, pain, obesity and cognition through the gut. “We have unpublished data showing that probiotics can enhance learning in animal models,” he tells me. His team tested the effects of two strains of bacteria, finding that one improved cognition in mice. His team is now embarking on human trials, to see if healthy volunteers can have their cognitive abilities enhanced or modulated by tweaking the gut microbiome.
Another method of adjusting the bacterial profile of your gut is to undergo a transplant that involves taking faecal material from a donor’s intestine – often a close relative – and implanting into a recipient via enema infusion. This unorthodox treatment has been shown to successfully treat infections caused by pathogenic bacteria colonising the gut.
Brain boost
Thankfully, Cryan has a far more appetising method on offer.  “Diet is perhaps the biggest factor in shaping the composition of the microbiome,” he says. A study by University College Cork researchers published in Nature in 2012 (http://www.nature.com/nature/journal/v488/n7410/full/nature11319.html?WT.ec_id=NATURE-20120809) followed 200 elderly people over the course of two years, as they transitioned into different environments such as nursing homes. The researchers found that their subjects’ health – frailty, cognition, and immune system – all correlated with their microbiome. From bacterial population alone, researchers could tell if a patient was a long-stay patient in a nursing home, or short-stay, or living in the general community. These changes were a direct reflection of their diet in these different environments. “A diverse diet gives you a diverse microbiome that gives you a better health outcome,” says Cryan.
Beyond a healthy and varied diet, though, it still remains to be discovered whether certain food combinations could alter the microbiome to produce a cognitive boost. In fact, Cryan recommends that claims from probiotic supplements of brain-boosting ought to be taken with a pinch of salt for now. “Unless the studies have been done, one can assume they’re not going to have any effect on mental health,” he says. Still, he’s optimistic about the future. “The field right now is evolving very strongly and quickly. There’s a lot of important research to be done. It’s still early days.”
Hacking the brain often conjures up ideas of electrical hardware such as implants and trans-cranial stimulators. But it might be the case that a simple change in diet can shift your brain up a gear. The transhumanists and body hackers who believe that technology is the sole way to improve human ability would do well to pay as much attention to the living augmentation that already resides in their gut.
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Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 23-02-2014, 09:11:36
A, evo i još o tome kako istraživanja i merenja nastoje da budu varljivija nego što bismo voleli:
 
  Lab equipment may take on a mind of its own to trick scientists (http://scienceblog.com/70583/lab-equipment-may-take-on-a-mind-of-its-own-to-trick-scientists/)
 
Quote
MIT researchers propose using distant quasars to test Bell’s theorem
In a paper published this week in the journal Physical Review Letters, MIT researchers propose an experiment that may close the last major loophole of Bell’s inequality — a 50-year-old theorem that, if violated by experiments, would mean that our universe is based not on the textbook laws of classical physics, but on the less-tangible probabilities of quantum mechanics.
 
Such a quantum view would allow for seemingly counterintuitive phenomena such as entanglement, in which the measurement of one particle instantly affects another, even if those entangled particles are at opposite ends of the universe. Among other things, entanglement — a quantum feature Albert Einstein skeptically referred to as “spooky action at a distance”— seems to suggest that entangled particles can affect each other instantly, faster than the speed of light.
 
In 1964, physicist John Bell took on this seeming disparity between classical physics and quantum mechanics, stating that if the universe is based on classical physics, the measurement of one entangled particle should not affect the measurement of the other — a theory, known as locality, in which there is a limit to how correlated two particles can be. Bell devised a mathematical formula for locality, and presented scenarios that violated this formula, instead following predictions of quantum mechanics.
 
Since then, physicists have tested Bell’s theorem by measuring the properties of entangled quantum particles in the laboratory. Essentially all of these experiments have shown that such particles are correlated more strongly than would be expected under the laws of classical physics — findings that support quantum mechanics.
 
However, scientists have also identified several major loopholes in Bell’s theorem. These suggest that while the outcomes of such experiments may appear to support the predictions of quantum mechanics, they may actually reflect unknown “hidden variables” that give the illusion of a quantum outcome, but can still be explained in classical terms.
 
Though two major loopholes have since been closed, a third remains; physicists refer to it as “setting independence,” or more provocatively, “free will.” This loophole proposes that a particle detector’s settings may “conspire” with events in the shared causal past of the detectors themselves to determine which properties of the particle to measure — a scenario that, however far-fetched, implies that a physicist running the experiment does not have complete free will in choosing each detector’s setting. Such a scenario would result in biased measurements, suggesting that two particles are correlated more than they actually are, and giving more weight to quantum mechanics than classical physics.
 
“It sounds creepy, but people realized that’s a logical possibility that hasn’t been closed yet,” says MIT’s David Kaiser, the Germeshausen Professor of the History of Science and senior lecturer in the Department of Physics. “Before we make the leap to say the equations of quantum theory tell us the world is inescapably crazy and bizarre, have we closed every conceivable logical loophole, even if they may not seem plausible in the world we know today?”
 
Now Kaiser, along with MIT postdoc Andrew Friedman and Jason Gallicchio of the University of Chicago, have proposed an experiment to close this third loophole by determining a particle detector’s settings using some of the oldest light in the universe: distant quasars, or galactic nuclei, which formed billions of years ago.
 
The idea, essentially, is that if two quasars on opposite sides of the sky are sufficiently distant from each other, they would have been out of causal contact since the Big Bang some 14 billion years ago, with no possible means of any third party communicating with both of them since the beginning of the universe — an ideal scenario for determining each particle detector’s settings.
 
As Kaiser explains it, an experiment would go something like this: A laboratory setup would consist of a particle generator, such as a radioactive atom that spits out pairs of entangled particles. One detector measures a property of particle A, while another detector does the same for particle B. A split second after the particles are generated, but just before the detectors are set, scientists would use telescopic observations of distant quasars to determine which properties each detector will measure of a respective particle. In other words, quasar A determines the settings to detect particle A, and quasar B sets the detector for particle B.
 
The researchers reason that since each detector’s setting is determined by sources that have had no communication or shared history since the beginning of the universe, it would be virtually impossible for these detectors to “conspire” with anything in their shared past to give a biased measurement; the experimental setup could therefore close the “free will” loophole. If, after multiple measurements with this experimental setup, scientists found that the measurements of the particles were correlated more than predicted by the laws of classical physics, Kaiser says, then the universe as we see it must be based instead on quantum mechanics.
 
“I think it’s fair to say this [loophole] is the final frontier, logically speaking, that stands between this enormously impressive accumulated experimental evidence and the interpretation of that evidence saying the world is governed by quantum mechanics,” Kaiser says.
 
Now that the researchers have put forth an experimental approach, they hope that others will perform actual experiments, using observations of distant quasars.
 
“At first, we didn’t know if our setup would require constellations of futuristic space satellites, or 1,000-meter telescopes on the dark side of the moon,” Friedman says. “So we were naturally delighted when we discovered, much to our surprise, that our experiment was both feasible in the real world with present technology, and interesting enough to our experimentalist collaborators who actually want to make it happen in the next few years.”
   
Adds Kaiser, “We’ve said, ‘Let’s go for broke — let’s use the history of the cosmos since the Big Bang, darn it.’ And it is very exciting that it’s actually feasible.”
   
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 23-02-2014, 09:21:08
Nisam čitao link, ali mi je poznato da laboratorijska oprema zna da bude zajebana. Posebno kad počne da daje rezultate koji se istraživaču "dopadaju".
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Albedo 0 on 23-02-2014, 11:47:19
pusti to, daj ove bakterije za inteligenciju! 8-)

Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: scallop on 23-02-2014, 12:04:30
Ti fale?
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Albedo 0 on 23-02-2014, 12:08:19
od sada pijem flonivin svaki dan! 8-)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Karl Rosman on 23-02-2014, 12:11:37
Da izbalansiras bakterije? Sranje i inteligenciju?

But, why?
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Albedo 0 on 23-02-2014, 12:40:26
od viška ne boli dupe!
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Karl Rosman on 23-02-2014, 12:52:11
od viška ne boli dupe!
Uh. Nisam bas siguran, ali verujem ti na rec!  :)


Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Albedo 0 on 23-02-2014, 13:03:54
inače, kad već pričamo o dopingu, jel tačno da se na ETF-u koristio kokain za vrijeme ispitnog roka? 8-)

Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 06-04-2014, 07:41:24
Dilema zašto kvantne procese ne vidimo na makroskopskom planu je dugo lomila mozgove poštenog sveta. E, sad, neki tvrde da imaju predlog rešenja:
 
 The Astounding Link Between the P≠NP Problem and the Quantum Nature of Universe (https://medium.com/the-physics-arxiv-blog/7ef5eea6fd7a)
 
Quote
With some straightforward logic, one theorist has shown that macroscopic quantum objects cannot exist if P≠NP, which suddenly explains one of the greatest mysteries in physics
 
The paradox of Schrodinger’s cat is a thought experiment dreamed up to explore one of the great mysteries of quantum mechanics—why we don’t see its strange and puzzling behaviour in the macroscopic world.
The paradox is simple to state. It involves a cat, a flask of poison and a source of radiation; all contained within a sealed box. If a monitor in the box detects radioactivity, the flask is shattered, releasing the poison and killing the cat.
 
 
The paradox comes about because the radioactive decay is a quantum process and so in a superposition of states until observed. The radioactive atom is both decayed and undecayed at the same time.
But that means the cat must also be in a superposition of alive and dead states until the box is open and the system is observed. In other words, the cat must be both dead and alive at the same time.
Nobody knows why we don’t observe these kinds of strange superpositions in the macroscopic world. For some reason, quantum mechanics just doesn’t work on that scale. And therein lies the mystery, one of the greatest in science.
But that mystery may now be solved thanks to the extraordinary work of Arkady Bolotin at Ben-Gurion University in Israel. He says the key is to think of Schrodinger’s cat as a problem of computational complexity theory. When he does that, it melts away.
First some background. The equation that describes the behaviour of quantum particles is called Schrodinger’s equation. It is relatively straightforward to solve for simple systems such as a single quantum particle in a box and predicts that these systems exist in a quantum superposition of states.
In principle, it ought to be possible to use Schrödinger’s equation to describe any object regardless of its size, perhaps even the universe itself. This equation predicts that the system being modelled exists in a superposition of states, even though this is never experienced in our macroscopic world.
The problem is that the equation says nothing about how large an object needs to be before it obeys Newtonian mechanics rather than the quantum variety.
Now Bolotin thinks he knows why there is a limit and where it lies. He says there is an implicit assumption when physicists say that Schrödinger’s equation can describe macroscopic systems. This assumption is that the equations can be solved in a reasonable amount of time to produce an answer.
That’s certainly true of simple systems but physicists well know that calculating the quantum properties of more complex systems is hugely difficult. The world’s most powerful supercomputers cough and splutter when asked to handle systems consisting of more than a few thousand quantum particles.
That leads Bolotin to ask a perfectly reasonable question. What if there is no way to solve Schrödinger’s equation for macroscopic systems in a reasonable period of time? “If it were so, then quantum theoretical constructions like “a quantum state of a macroscopic object” or “the wave function of the universe” would be nothing more than nontestable empty abstractions,” he says.
He then goes on to prove that this is exactly the case, with one important proviso: that P ≠ NP. Here’s how he does it.
His first step is to restate Schrödinger’s equation as a problem of computational complexity. For a simple system, the equation can be solved by an ordinary computer in a reasonable time, so it falls into class of computational problems known as NP.
Bolotin then goes on to show that the problem of solving the Schrödinger equation is at least as hard or harder than any problem in the NP class. This makes it equivalent to many other head-scratchers such as the travelling salesman problem. Computational complexity theorists call these problems NP-hard.
What’s interesting about NP-hard problems is that they are mathematically equivalent. So a solution for one automatically implies a solution for them all. The biggest question in computational complexity theory (and perhaps in all of physics, if the computational complexity theorists are to be believed), is whether they can be solved in this way or not.
 
(http://i59.tinypic.com/2oy05.png)
 The class of problems that can be solved quickly and efficiently is called P. So the statement that NP-hard problems can also be solved quickly and efficiently is the famous P=NP equation.
But since nobody has found such a solution, the general belief is that they cannot be solved in this way. Or as computational complexity theorists put it: P ≠ NP. Nobody has yet proved this, but most theorists would bet their bottom dollar that it is true.
Schrödinger’s equation has a direct bearing on this. If the equation can be quickly and efficiently solved in all cases, including for vast macroscopic states, then it must be possible to solve all other NP-hard problems in the same way. That is equivalent to saying that P=NP.
But if P is not equal to NP, as most experts believe, then there is a limit to the size the quantum system can be. Indeed, that is exactly what physicists observe.
Bolotin goes on to flesh this out with some numbers. If P ≠ NP and there is no efficient algorithm for solving Schrödinger’s equation, then there is only one way of finding a solution, which is a brute force search.
In the travelling salesman problem of finding the shortest way of visiting a number of cities, the brute force solution involves measuring the length of all permutations of routes and then seeing which is shortest. That’s straightforward for a small number of cities but rapidly becomes difficult for large numbers of them.
Exactly the same is true of Schrödinger’s equation. It’s straightforward for a small number of quantum particles but for a macroscopic system, it becomes a monster.
Macroscopic systems are made up of a number of constituent particles about equal to Avogadro’s number, which is 10^24.
So the number of elementary operations needed to exactly solve this equation would be equal to 2^10^24. That’s a big number!
To put it in context, Bolotin imagines a computer capable of solving it over a reasonable running time of, say, a year. Such a computer would need to execute each elementary operation on a timescale of the order of 10^(-3x10^23) seconds.
This time scale is so short that it is difficult to imagine. But to put it in context, Bolotin says there would be little difference between running such a computer over one year and, say, one hundred billion years (10^18 seconds), which is several times longer than the age of the universe.
What’s more, this time scale is considerably shorter than the Planck timescale, which is roughly equal to 10^-43 seconds. It’s simply not possible to measure or detect change on a scale shorter than this. So even if there was a device capable of doing this kind of calculating, there would be no way of detecting that it had done anything.
“So, unless the laws of physics (as we understand them today) were wrong, no computer would ever be able to execute [this number of] operations in any reasonable amount time,” concludes Bolotin.
In other words, macroscopic systems cannot be quantum in nature. Or as Bolotin puts it: “For anyone living in the real physical world (of limited computational resources) the Schrodinger equation will turn out to be simply unsolvable for macroscopic objects.”
That’s a fascinating piece of logic in a remarkably clear and well written paper. It also raises an interesting avenue for experiment. Physicists have become increasingly skilled at creating conditions in which ever larger objects demonstrate quantum behaviour.
The largest quantum object so far—a vibrating silicon springboard —contained around 1 trillion atoms (10^15), significantly less than Avogadro’s number. But Bolotin’s work suggests a clear size limit.
So in theory, these kinds of experiments provide a way to probe the computational limits of the universe. What’s needed, of course, is a clear prediction from his theory that allows it to be tested experimentally.
There is also a puzzle. There are well known quantum states that do contain Avogadro’s number of particles: these include superfluids, supeconductors, lasers and so on. It would be interesting to see Bolotin’s treatment of these from the point of view of computational complexity.
In these situations, all the particles occupy the same ground state, which presumably significantly reduces the complexity. But by how much? Does his approach have anything to say about how big these states can become?
Beyond that, the questions come thick and fast. What of the transition between quantum and classical states—how does that happen in terms of computational complexity? What of the collapse of stars, which are definitely classical objects, into black holes, which may be quantum ones?
And how does the universe decide whether a system is going to be quantum or not? What is the mechanism by which computational complexity exerts its influence over nature? And so on…
The computational complexity theorist Scott Aaronson has long argued (http://arxiv.org/abs/1108.1791) that the most interesting problems in physics are intricately linked with his discipline. And Bolotin’s new work shows why. It’s just possible that computational complexity theory could be quantum physics’ next big thing.
Ref: arxiv.org/abs/1403.7686 (http://arxiv.org/abs/1403.7686) : Computational Solution to Quantum Foundational Problems

Follow the Physics arXiv Blog by hitting the Follow button below, on Twitter at @arxivblog (https://twitter.com/arxivblog) and now also on Facebook (https://www.facebook.com/pages/The-Physics-Arxiv-Blog/211397089067055)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 26-06-2014, 09:15:45
Meni je veoma teško da se ovde razaberem, ali evo nekih indicija da je brzina svetlosti možda malo manja nego što smo se slagali poslednjih stotinak godina. Pošto ima masa grafikona u tekstu, ne kopiram ga, samo link:


First Evidence Of A Correction To The Speed of Light (https://medium.com/the-physics-arxiv-blog/first-evidence-of-a-correction-to-the-speed-of-light-65c61311b08a)





Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Father Jape on 26-06-2014, 13:03:16
http://www.ted.com/talks/naomi_oreskes_why_we_should_believe_in_science (http://www.ted.com/talks/naomi_oreskes_why_we_should_believe_in_science)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 09-10-2014, 09:41:35
Uspešna teleportacija više kvantnih vrednosti fotona:


https://medium.com/the-physics-arxiv-blog/first-teleportation-of-multiple-quantum-properties-of-a-single-photon-7c1e61598565


Ovo sigurno znači da smo na KORAK od kvantne komunikacije!!!!!!!!!!!  :-| :-| :-| :-| :-| :-| :-| :-|
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Mica Milovanovic on 09-10-2014, 09:58:54
Skote, gde si sad kad si mi najpotrebniji za teleportaciju?
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 31-10-2014, 10:28:46
How Could Quantum Physics Get Stranger? Shattered Wave Functions (http://motherboard.vice.com/read/how-could-quantum-physics-get-weirder-shattered-wavefunctions)



Quote
A team of physicists based at Brown University has succeeded in shattering a quantum wave function. That near-mythical representation of indeterminate reality, in which an unmeasured particle is able to occupy many states simultaneously, can be dissected into many parts. This dissection, which is described this week in the Journal of Low Temperature Physics (http://link.springer.com/article/10.1007/s10909-014-1224-3), has the potential to turn how we view the quantum world on its head.
 When we say some element of the quantum world occupies many states at once, what’s really being referred to is the element’s wave function. A wave function can be viewed as a space occupied simultaneously by many different possibilities or degrees of freedom.
 If a particle could be in position (x,y,z) in three-dimensional space, there are probabilities that it could specifically be at (x1,y1,z1) or (x2,y2,z2) and so forth, and this is represented in the wave function, which is all of these possibilities added together. Even what we’d normally (deterministically) consider empty space has a wave function and, as such, contains very real possibilities of not being empty. Sometimes this manifests as real “virtual” particles.
 Visually, we might imagine a particle in its undisturbed state looking more like a cloud than a point in space. Imagine tracing out all of your movements for a couple of weeks or months on a map or satellite image. It might look a bit like that cloud, only instead of describing past events, the electron cloud would describe precisely right now. Weird, eh? What makes it even cooler is that a bunch of particles can share these states at the same time, effectively becoming instances of the same particle. And so: entanglement.
 It’s possible to strip away all of this indeterminateness. To do so is actually quite easy; wave functions are very fragile, subject to a “collapse” in which all of those possibilities become just a single particle at a single point at a single time. That’s what happens when a macroscopic human attempts to measure a quantum mechanical system: The wave drops away and all that’s left is a boring, well-defined thing.


 What the Brown researchers, led by physicist Humphrey Maris, found is that it’s possible to take a wave function and isolate it into different parts. So, if our electron has some probability of being in position (x1,y1,z1) and another probability of being in position (x2,y2,z2), those two probabilities can be isolated from each other, cordoned off like quantum crime scenes. According to Maris and his team, this can be achieved (and has been achieved) using tiny bubbles of helium as physical “traps.”
 “We are trapping the chance of finding the electron, not pieces of the electron,” Maris said in a statement provided by Brown University (https://news.brown.edu/articles/2014/10/electron). “It’s a little like a lottery. When lottery tickets are sold, everyone who buys a ticket gets a piece of paper. So all these people are holding a chance and you can consider that the chances are spread all over the place. But there is only one prize—one electron—and where that prize will go is determined later.”
 Maris is chasing a fairly old mystery with this work. In experiments dating back to the 1960s, physicists have observed a very peculiar behavior of electrons in supercooled baths of helium. When an electron enters the bath, it acts to repel the surrounding helium atoms, forming its own little bubble or cavity in the process. These bubbles then drift slowly downwards toward the bottom of the bath and a waiting detector. The bubbles should all be the same size and, thus, should fall at the same rate. Yet, something much stranger happens.
 The electron bubbles aren’t the first things to hit the detector in this experimental setup. Before they arrive as anticipated, the detector begins registering a series of mystery objects. This has been repeated many times over the years and explanations have included impurities in the helium bath or the possibility of electrons coupling to the helium atoms, which would then register negative charges at the detector.
 The Brown team argues that the only explanation that fits is their solution, a sort of fission reaction that breaks apart the electron wave function into roughly the same sizes of the mystery objects detected above. So, it’s not new and different objects hitting the detector first, it’s just different aspects or relics of the same electron, slivers of that cloud of possibilities. That an electron (or other particle) can be in many places at the same time is strange enough, but the notion that those possibilities can be captured and shuttled away adds a whole new twist.
 Ultimately, the wave function isn’t a physical thing. It’s mathematics that describe a phenomenon. So, it’s not as if in these extra bubbles we might find some “part” of an electron. The electron, upon measurement, will be in precisely one bubble. Or that would be the case if we assume the helium itself isn’t capable of causing the same sort of disturbance as a human measurement, causing its own wave function collapse with its own sort of “measurement.”
 “No one is sure what actually constitutes a measurement,” Maris said. “Perhaps physicists can agree that someone with a Ph.D. wearing a white coat sitting in the lab of a famous university can make measurements. But what about somebody who really isn’t sure what they are doing? Is consciousness required? We don’t really know.”
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 11-12-2014, 12:36:49
Ovo možda i nije idealan topik za ovaj članak al eto ga:



2 Futures Can Explain Time's Mysterious Past  (http://www.scientificamerican.com/article/2-futures-can-explain-time-s-mysterious-past/)





Quote
New theories suggest the big bang was not the beginning, and that we may live in the past of a parallel universe


Physicists have a problem with time.
 
 Whether through Newton’s gravitation, Maxwell’s electrodynamics, Einstein’s special and general relativity or quantum mechanics, all the equations that best describe our universe work perfectly if time flows forward or backward.
 
 Of course the world we experience is entirely different. The universe is expanding, not contracting. Stars emit light rather than absorb it, and radioactive atoms decay rather than reassemble. Omelets don’t transform back to unbroken eggs and cigarettes never coalesce from smoke and ashes. We remember the past, not the future, and we grow old and decrepit, not young and rejuvenated. For us, time has a clear and irreversible direction. It flies forward like a missile, equations be damned.
 
 For more than a century, the standard explanation for “time’s arrow,” as the astrophysicist Arthur Eddington first called it in 1927, has been that it is an emergent property of thermodynamics, as first laid out in the work of the 19th-century Austrian physicist Ludwig Boltzmann. In this view what we perceive as the arrow of time is really just the inexorable rearrangement of highly ordered states into random, useless configurations, a product of the universal tendency for all things to settle toward equilibrium with one another.
 
 Informally speaking, the crux of this idea is that “things fall apart,” but more formally, it is a consequence of the second law of thermodynamics, which Boltzmann helped devise. The law states that in any closed system (like the universe itself), entropy—disorder—can only increase. Increasing entropy is a cosmic certainty because there are always a great many more disordered states than orderly ones for any given system, similar to how there are many more ways to scatter papers across a desk than to stack them neatly in a single pile.
 
 The thermodynamic arrow of time suggests our observable universe began in an exceptionally special state of high order and low entropy, like a pristine cosmic egg materializing at the beginning of time to be broken and scrambled for all eternity. From Boltzmann’s era onward, scientists allergic to the notion of such an immaculate conception have been grappling with this conundrum.
 
 Boltzmann, believing the universe to be eternal in accordance with Newton’s laws, thought that eternity could explain a low-entropy origin for time’s arrow. Given enough time—endless time, in fact—anything that can happen will happen, including the emergence of a large region of very low entropy as a statistical fluctuation from an ageless, high-entropy universe in a state of near-equilibrium. Boltzmann mused that we might live in such an improbable region, with an arrow of time set by the region’s long, slow entropic slide back into equilibrium.
 
 Today’s cosmologists have a tougher task, because the universe as we now know it isn’t ageless and unmoving: They have to explain the emergence of time’s arrow within a dynamic, relativistic universe that apparently began some 14 billion years ago in the fiery conflagration of the big bang. More often than not the explanation involves ‘fine-tuning’—the careful and arbitrary tweaking of a theory’s parameters to accord with observations.
 
 Many of the modern explanations for a low-entropy arrow of time involve a theory called inflation—the idea that a strange burst of antigravity ballooned the primordial universe to an astronomically larger size, smoothing it out into what corresponds to a very low-entropy state from which subsequent cosmic structures could emerge. But explaining inflation itself seems to require even more fine-tuning. One of the problems is that once begun, inflation tends to continue unstoppably. This “eternal inflation” would spawn infinitudes of baby universes about which predictions and observations are, at best, elusive. Whether this is an undesirable bug or a wonderful feature of the theory is a matter of fierce debate; for the time being it seems that inflation’s extreme flexibility and explanatory power are both its greatest strength and its greatest weakness.
 
 For all these reasons, some scientists seeking a low-entropy origin for time’s arrow find explanations relying on inflation slightly unsatisfying. “There are many researchers now trying to show in some natural way why it’s reasonable to expect the initial entropy of the universe to be very low,” says David Albert, a philosopher and physicist at Columbia University. “There are even some who think that the entropy being low at the beginning of the universe should just be added as a new law of physics.”
 
 That latter idea is tantamount to despairing cosmologists simply throwing in the towel. Fortunately, there may be another way.
 
 Tentative new work from Julian Barbour of the University of Oxford, Tim Koslowski of the University of New Brunswick and Flavio Mercati of the Perimeter Institute for Theoretical Physics suggests that perhaps the arrow of time doesn’t really require a fine-tuned, low-entropy initial state at all but is instead the inevitable product of the fundamental laws of physics. Barbour and his colleagues argue that it is gravity, rather than thermodynamics, that draws the bowstring to let time’s arrow fly. Their findings (http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.181101#fulltext) were published in October in Physical Review Letters.
 
 The team’s conclusions come from studying an exceedingly simple proxy for our universe, a computer simulation of 1,000 pointlike particles interacting under the influence of Newtonian gravity. They investigated the dynamic behavior of the system using a measure of its "complexity," which corresponds to the ratio of the distance between the system’s closest pair of particles and the distance between the most widely separated particle pair. The system’s complexity is at its lowest when all the particles come together in a densely packed cloud, a state of minimum size and maximum uniformity roughly analogous to the big bang. The team’s analysis showed that essentially every configuration of particles, regardless of their number and scale, would evolve into this low-complexity state. Thus, the sheer force of gravity sets the stage for the system’s expansion and the origin of time’s arrow, all without any delicate fine-tuning to first establish a low-entropy initial condition.
 
 From that low-complexity state, the system of particles then expands outward in both temporal directions, creating two distinct, symmetric and opposite arrows of time. Along each of the two temporal paths, gravity then pulls the particles into larger, more ordered and complex structures—the model’s equivalent of galaxy clusters, stars and planetary systems. From there, the standard thermodynamic passage of time can manifest and unfold on each of the two divergent paths. In other words, the model has one past but two futures. As hinted by the time-indifferent laws of physics, time’s arrow may in a sense move in two directions, although any observer can only see and experience one. “It is the nature of gravity to pull the universe out of its primordial chaos and create structure, order and complexity,” Mercati says. “All the solutions break into two epochs, which go on forever in the two time directions, divided by this central state which has very characteristic properties.”
 
 Although the model is crude, and does not incorporate either quantum mechanics or general relativity, its potential implications are vast. If it holds true for our actual universe, then the big bang could no longer be considered a cosmic beginning but rather only a phase in an effectively timeless and eternal universe. More prosaically, a two-branched arrow of time would lead to curious incongruities for observers on opposite sides. “This two-futures situation would exhibit a single, chaotic past in both directions, meaning that there would be essentially two universes, one on either side of this central state,” Barbour says. “If they were complicated enough, both sides could sustain observers who would perceive time going in opposite directions. Any intelligent beings there would define their arrow of time as moving away from this central state. They would think we now live in their deepest past.”
 
 What’s more, Barbour says, if gravitation does prove to be fundamental to the arrow of time, this could sooner or later generate testable predictions and potentially lead to a less “ad hoc” explanation than inflation for the history and structure of our observable universe.
 
 This is not the first rigorous two-futures solution for time’s arrow. Most notably, California Institute of Technology cosmologist Sean Carroll and a graduate student, Jennifer Chen, produced their own branching model in 2004, one that sought to explain the low-entropy origin of time’s arrow in the context of cosmic inflation and the creation of baby universes. They attribute the arrow of time’s emergence in their model not so much to entropy being very low in the past but rather to entropy being so much higher in both futures, increased by the inflation-driven creation of baby universes.
 
 A decade on, Carroll is just as bullish about the prospect that increasing entropy alone is the source for time’s arrow, rather than other influences such as gravity. “Everything that happens in the universe to distinguish the past from the future is ultimately because the entropy is lower in one direction and higher in the other,” Carroll says. “This paper by Barbour, Koslowski and Mercati is good because they roll up their sleeves and do the calculations for their specific model of particles interacting via gravity, but I don’t think it’s the model that is interesting—it’s the model’s behavior being analyzed carefully…. I think basically any time you have a finite collection of particles in a really big space you’ll get this kind of generic behavior they describe. The real question is, is our universe like that? That’s the hard part.”
 
 Together with Alan Guth, the Massachusetts Institute of Technology cosmologist who pioneered the theory of inflation, Carroll is now working on a thermodynamic response of sorts to the new claims for a gravitational arrow of time: Another exceedingly simple particle-based model universe that also naturally gives rise to time’s arrow, but without the addition of gravity or any other forces. The thermodynamic secret to the model’s success, they say, is assuming that the universe has an unlimited capacity for entropy.
 
 “If we assume there is no maximum possible entropy for the universe, then any state can be a state of low entropy,” Guth says. “That may sound dumb, but I think it really works, and I also think it’s the secret of the Barbour et al construction. If there’s no limit to how big the entropy can get, then you can start anywhere, and from that starting point you’d expect entropy to rise as the system moves to explore larger and larger regions of phase space. Eternal inflation is a natural context in which to invoke this idea, since it looks like the maximum possible entropy is unlimited in an eternally inflating universe.”
 
 The controversy over time’s arrow has come far since the 19th-century ideas of Boltzmann and the 20th-century notions of Eddington, but in many ways, Barbour says, the debate at its core remains appropriately timeless. “This is opening up a completely new way to think about a fundamental problem, the nature of the arrow of time and the origin of the second law of thermodynamics,” Barbour says. “But really we’re just investigating a new aspect of Newton’s gravitation, which hadn’t been noticed before. Who knows what might flow from this with further work and elaboration?”
 
 “Arthur Eddington coined the term ‘arrow of time,’ and famously said the shuffling of material and energy is the only thing which nature cannot undo,” Barbour adds. “And here we are, showing beyond any doubt really that this is in fact exactly what gravity does. It takes systems that look extraordinarily disordered and makes them wonderfully ordered. And this is what has happened in our universe. We are realizing the ancient Greek dream of order out of chaos.”

Rilejtid riding:


http://eddiesblogonenergyandphysics.blogspot.com/2014/03/what-is-cause-of-arrow-of-time.html (http://eddiesblogonenergyandphysics.blogspot.com/2014/03/what-is-cause-of-arrow-of-time.html)

http://www.nariphaltan.org/time.pdf (http://www.nariphaltan.org/time.pdf)

http://www.nariphaltan.org/origin.pdf (http://www.nariphaltan.org/origin.pdf)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 25-01-2015, 09:27:38
The Paradoxes That Threaten To Tear Modern Cosmology Apart (https://medium.com/the-physics-arxiv-blog/the-paradoxes-that-threaten-to-tear-modern-cosmology-apart-d334a7fcfdb6)
 
 
Quote
Revolutions in science often come from the study of seemingly unresolvable paradoxes. An intense focus on these paradoxes, and their eventual resolution, is a process that has leads to many important breakthroughs.
So an interesting exercise is to list the paradoxes associated with current ideas in science. It’s just possible that these paradoxes will lead to the next generation of ideas about the universe.
Today, Yurij Baryshev at St Petersburg State University in Russia does just this with modern cosmology. The result is a list of paradoxes associated with well-established ideas and observations about the structure and origin of the universe.
Perhaps the most dramatic, and potentially most important, of these paradoxes comes from the idea that the universe is expanding, one of the great successes of modern cosmology. It is based on a number of different observations.
The first is that other galaxies are all moving away from us. The evidence for this is that light from these galaxies is red-shifted. And the greater the distance, the bigger this red-shift.
Astrophysicists interpret this as evidence that more distant galaxies are travelling away from us more quickly. Indeed, the most recent evidence is that the expansion is accelerating.
What’s curious about this expansion is that space, and the vacuum associated with it, must somehow be created in this process. And yet how this can occur is not at all clear. “The creation of space is a new cosmological phenomenon, which has not been tested yet in physical laboratory,” says Baryshev.
What’s more, there is an energy associated with any given volume of the universe. If that volume increases, the inescapable conclusion is that this energy must increase as well. And yet physicists generally think that energy creation is forbidden.
Baryshev quotes the British cosmologist, Ted Harrison, on this topic: “The conclusion, whether we like it or not, is obvious: energy in the universe is not conserved,” says Harrison.
This is a problem that cosmologists are well aware of. And yet ask them about it and they shuffle their feet and stare at the ground. Clearly, any theorist who can solve this paradox will have a bright future in cosmology.
The nature of the energy associated with the vacuum is another puzzle. This is variously called the zero point energy or the energy of the Planck vacuum and quantum physicists have spent some time attempting to calculate it.
These calculations suggest that the energy density of the vacuum is huge, of the order of 10^94 g/cm^3. This energy, being equivalent to mass, ought to have a gravitational effect on the universe.
Cosmologists have looked for this gravitational effect and calculated its value from their observations (they call it the cosmological constant). These calculations suggest that the energy density of the vacuum is about 10^-29 g/cm3.
Those numbers are difficult to reconcile. Indeed, they differ by 120 orders of magnitude. How and why this discrepancy arises is not known and is the cause of much bemused embarrassment among cosmologists.
Then there is the cosmological red-shift itself, which is another mystery. Physicists often talk about the red-shift as a kind of Doppler effect, like the change in frequency of a police siren as it passes by.
The Doppler effect arises from the relative movement of different objects. But the cosmological red-shift is different because galaxies are stationary in space. Instead, it is space itself that cosmologists think is expanding.
The mathematics that describes these effects is correspondingly different as well, not least because any relative velocity must always be less than the speed of light in conventional physics. And yet the velocity of expanding space can take any value.
Interestingly, the nature of the cosmological red-shift leads to the possibility of observational tests in the next few years. One interesting idea is that the red-shifts of distant objects must increase as they get further away. For a distant quasar, this change may be as much as one centimetre per second per year, something that may be observable with the next generation of extremely large telescopes.
One final paradox is also worth mentioning. This comes from one of the fundamental assumptions behind Einstein’s theory of general relativity—that if you look at the universe on a large enough scale, it must be the same in all directions.
It seems clear that this assumption of homogeneity does not hold on the local scale. Our galaxy is part of a cluster known as the Local Group which is itself part of a bigger supercluster.
This suggests a kind of fractal structure to the universe. In other words, the universe is made up of clusters regardless of the scale at which you look at it.
The problem with this is that it contradicts one of the basic ideas of modern cosmology—the Hubble law. This is the observation that the cosmological red-shift of an object is linearly proportional to its distance from Earth.
It is so profoundly embedded in modern cosmology that most currently accepted theories of universal expansion depend on its linear nature. That’s all okay if the universe is homogeneous (and therefore linear) on the largest scales.
But the evidence is paradoxical. Astrophysicists have measured the linear nature of the Hubble law at distances of a few hundred megaparsecs. And yet the clusters visible on those scales indicate the universe is not homogeneous on the scales.
And so the argument that the Hubble law’s linearity is a result of the homogeneity of the universe (or vice versa) does not stand up to scrutiny. Once again this is an embarrassing failure for modern cosmology.
It is sometimes tempting to think that astrophysicists have cosmology more or less sewn up, that the Big Bang model, and all that it implies, accounts for everything we see in the cosmos.
Not even close. Cosmologists may have successfully papered over the cracks in their theories in a way that keeps scientists happy for the time being. This sense of success is surely an illusion.
And that is how it should be. If scientists really think they are coming close to a final and complete description of reality, then a simple list of paradoxes can do a remarkable job of putting feet firmly back on the ground.
Ref: arxiv.org/abs/1501.0191 (http://arxiv.org/abs/1501.01919)9 : Paradoxes Of Cosmological Physics In The Beginning Of The 21-St Century
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 31-01-2015, 09:44:59
Prelepo!

 The Quantum Experiment That Simulates A Time Machine (https://medium.com/the-physics-arxiv-blog/the-quantum-experiment-that-simulates-a-time-machine-185a7cc9bd11)
 
 
Quote
Physicists have simulated a photon interacting with an older version of itself in an experiment that could help reconcile quantum mechanics and relativity
One of the curiosities of general relativity is that it seems to allow time travel. Various physicists have discovered solutions to Einstein’s field equations that contain loops that return to the same point in space and time. Physicists call them closed time-like curves.
At first glance, these kinds of time machines seem to lead to all kinds of problems, such as the grandfather paradox. This is where somebody travels back in time and kills their grandfather meaning they could never have been born and so could not have gone back to kill the grandfather.
That’s just bizarre so physicists have attempted to find ways to prevent these paradoxes. In the early 90s, for example, cosmologists showed that a billiard ball entering a wormhole that leads to a closed time-like curve must always meet its older self coming out of the wormhole. What’s more, the resulting collision always prevents the ball entering the wormhole in the first place. In other words, the billiard ball would simply bounce off the entrance to a closed time-like curve.
So much for classical objects and time travel. But what would happen if a quantum particle entered a closed time-like curve? In the early 90s, the physicist David Deutsch showed that not only is this possible but that it can only happen in a way that does not allow superluminal signalling. So quantum mechanics plays havoc with causality but in a way that is consistent with relativity and so prevents grandfather-type paradoxes.
Deutsch’s result has extraordinary implications. It implies that closed time-like curves can be used to solve NP-complete problems in polynomial time and to violate Heisenberg’s uncertainty principle.(https://d262ilb51hltx0.cloudfront.net/max/800/1*Hpf0ynH0E8E3bLIo46-N_Q.png)As far as we can tell, nobody has ever created a Deutsch closed time-like curve. So it’s easy to imagine that until we do, we will never know whether Deutsch’s predictions are true. But today Martin Ringbauer and a few pals at the University of Queensland in Australia say that it’s not necessary to create a closed time -like curve to test how it behaves.
Instead, these guys have created a quantum system that reproduces the behaviour of a photon passing through a closed time-like curve and interacting with its older self. In other words, these guys have built a time machine simulator.
That is not quite as far-fetched as it sounds. Physicists have long known that one quantum system can be used to simulate another. In fact, an emerging area of quantum science is devoted to this practice. “Although no closed time-like curves have been discovered to date, quantum simulation nonetheless enables us to study their unique properties and behaviour,” say Ringbauer and co.
The quantum system that they want to simulate is straightforward to describe. It consists of a photon interacting with an older version of itself. That’s equivalent to a single photon interacting with another trapped in a closed time-like curve.
That turns out to be straightforward to simulate using a pair of entangled photons. These are photon pairs created from a single photon and so therefore share the same existence in the form of a wave function.
Ringbauer and co send these photons through an optical circuit which gives them arbitrary polarisation states and then allows them to interfere when they hit a partially polarising beam splitter. By carefully setting the experimental parameters, this entangled system can simulate the behaviour of a photon interacting with an older version of itself.
The result of this interaction can be determined by detecting the pattern of photons that emerges from the beam splitter.
The results make for interesting reading. Ringbauer and co say they can use the system to distinguish between quantum states that are prepared in seemingly identical ways, something that is otherwise not possible. They can also use the time machine simulator to tell apart quantum states that are ordinarily impossible to distinguish.(https://d262ilb51hltx0.cloudfront.net/max/1386/1*QArQ-gFRk1yNVmJTbjCLMA.png)But perhaps most significant is that all their observations are compatible with relativity. At no point does the time machine-simulator lead to grandfather-type paradoxes, regardless of the tricks it plays with causality. That’s just as Deutsch predicted.
There are some curious wrinkles in these results too. For example, Ringbauer and co say that quantum inputs can change the output in a non-linear way but only for some experimental set ups. In other words, they can control the way the experiment twists causality, which is an interesting avenue for exploring just how far it is possible to distort cause and effect.
That’s a fascinating experiment which leads to some tantalising new ways to probe the link between quantum mechanics and relativity. As Ringbauer and co conclude: “Our study of the Deutsch model provides insights into the role of causal structures and non-linearities in quantum mechanics, which is essential for an eventual reconciliation with general relativity.”
There’s plenty more work to be done here, even before they fire up their Delorean. Worth watching.
Ref: arxiv.org/abs/1501.0501 (http://arxiv.org/abs/1501.05014)4 : Experimental Simulation of Closed Timelike Curves

Follow the Physics arXiv Blog on Twitter at @arxivblog (https://twitter.com/arxivblog) and on Facebook (https://www.facebook.com/pages/The-Physics-Arxiv-Blog/211397089067055)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 30-08-2015, 08:16:04
Još malo kvantne fizike:
 Quantum ‘spookiness’ passes toughest test yet (http://www.nature.com/news/quantum-spookiness-passes-toughest-test-yet-1.18255)
 
Quote
Experiment plugs loopholes in previous demonstrations of 'action at a distance', against Einstein's objections — and could make data encryption safer.
 
 
It’s a bad day both for Albert Einstein and for hackers. The most rigorous test of quantum theory ever carried out has confirmed that the ‘spooky action at a distance’ that the German physicist famously hated — in which manipulating one object instantaneously seems to affect another, far away one — is an inherent part of the quantum world.
                                                            
The experiment, performed in the Netherlands, could be the final nail in the coffin for models of the atomic world that are more intuitive than standard quantum mechanics, say some physicists. It could also enable quantum engineers to develop a new suite of ultrasecure cryptographic devices.
                                                            
“From a fundamental point of view, this is truly history-making,” says Nicolas Gisin, a quantum physicist at the University of Geneva in Switzerland.
Einstein's annoyance
 
In quantum mechanics, objects can be in multiple states simultaneously: for example, an atom can be in two places, or spin in opposite directions, at once. Measuring an object forces it to snap into a well-defined state. Furthermore, the properties of different objects can become ‘entangled’, meaning that their states are linked: when a property of one such object is measured, the properties of all its entangled twins become set, too.
 This idea galled Einstein because it seemed that this ghostly influence would be transmitted instantaneously between even vastly separated but entangled particles — implying that it could contravene the universal rule that nothing can travel faster than the speed of light. He proposed that quantum particles do have set properties before they are measured, called hidden variables. And even though those variable cannot be access, he suggested that they pre-program entangled particles to behave in correlated ways.
In the 1960s, Irish physicist John Bell (http://www.nature.com/news/physics-bell-s-theorem-still-reverberates-1.15435) proposed a test that could discriminate between Einstein’s hidden variables and the spooky interpretation of quantum mechanics1 (http://www.nature.com/news/quantum-spookiness-passes-toughest-test-yet-1.18255#b1). He calculated that hidden variables can explain correlations only up to some maximum limit. If that level is exceeded, then Einstein’s model must be wrong.
The first Bell test was carried out in 19812 (http://www.nature.com/news/quantum-spookiness-passes-toughest-test-yet-1.18255#b2), by Alain Aspect’s team at the Institute of Optics in Palaiseau, France. Many more have been performed since, always coming down on the side of spookiness — but each of those experiments has had loopholes that meant that physicists have never been able to fully close the door on Einstein’s view. Experiments that use entangled photons are prone to the ‘detection loophole’: not all photons produced in the experiment are detected, and sometimes as many as 80% are lost. Experimenters therefore have to assume that the properties of the photons they capture are representative of the entire set.
To get around the detection loophole, physicists often use particles that are easier to keep track of than photons, such as atoms. But it is tough to separate distant atoms apart without destroying their entanglement. This opens the ‘communication loophole (http://www.nature.com/news/cosmic-light-could-close-quantum-weirdness-loophole-1.14771)’: if the entangled atoms are too close together, then, in principle, measurements made on one could affect the other without violating the speed-of-light limit.
   Entanglement swapping                                                            In the latest paper3 (http://www.nature.com/news/quantum-spookiness-passes-toughest-test-yet-1.18255#b3), which was submitted to the arXiv preprint repository on 24 August and has not yet been peer reviewed, a team led by Ronald Hanson of Delft University of Technology reports the first Bell experiment that closes both the detection and the communication loopholes. The team used a cunning technique called entanglement swapping to combine the benefits of using both light and matter. The researchers started with two unentangled electrons sitting in diamond crystals held in different labs on the Delft campus, 1.3 kilometres apart. Each electron was individually entangled with a photon, and both of those photons were then zipped to a third location. There, the two photons were entangled with each other — and this caused both their partner electrons to become entangled, too.
This did not work every time. In total, the team managed to generate 245 entangled pairs of electrons over the course of nine days. The team's measurements exceeded Bell’s bound, once again supporting the standard quantum view. Moreover, the experiment closed both loopholes at once: because the electrons were easy to monitor, the detection loophole was not an issue, and they were separated far enough apart to close the communication loophole, too.
“It is a truly ingenious and beautiful experiment,” says Anton Zeilinger, a physicist at the Vienna Centre for Quantum Science and Technology.
“I wouldn’t be surprised if in the next few years we see one of the authors of this paper, along with some of the older experiments, Aspect’s and others, named on a Nobel prize,” says Matthew Leifer, a quantum physicist at the Perimeter Institute in Waterloo for Theoretical Physics, Ontario. “It’s that exciting.”
A loophole-free Bell test also has crucial implications for quantum cryptography, says Leifer. Companies already sell systems that use quantum mechanics to block eavesdroppers. The systems produce entangled pairs of photons, sending one photon in each pair to the first user and the other photon to the second user. The two users then turn these photons into a cryptographic key that only they know. Because observing a quantum system disrupts its properties, if someone tries to eavesdrop on this process it will produce a noticeable effect, setting off an alarm.
   The final chink                                                            But loopholes, and the detection loophole in particular, leave the door open to sophisticated eavesdroppers. Through this loophole, malicious companies could sell devices that fool users into thinking that they are getting quantum-entangled particles, while they are instead being given keys that the company can use to spy on them. In 1991, quantum physicist Artur Ekert observed4 (http://www.nature.com/news/quantum-spookiness-passes-toughest-test-yet-1.18255#b4) that integrating a Bell test into the cryptographic system also would ensure that the system uses a genuine quantum process. For this to be valid, however, the Bell test must be free of any loopholes that a hacker could exploit. The Delft experiment “is the final proof that quantum cryptography can be unconditionally secure”, Zeilinger says.
In practice, however, the entanglement-swapping idea will be hard to implement. The team took more than week to generate a few hundred entangled electron pairs, whereas generating a quantum key would require thousands of bits to be processed per minute, points out Gisin, who is a co-founder of the quantum cryptographic company ID Quantique in Geneva.
Zeilinger also notes that there remains one last, somewhat philosophical loophole, first identified by Bell himself: the possibility that hidden variables could somehow manipulate the experimenters’ choices of what properties to measure, tricking them into thinking quantum theory is correct.
Leifer is less troubled by this ‘freedom-of-choice loophole’, however. “It could be that there is some kind of superdeterminism, so that the choice of measurement settings was determined at the Big Bang,” he says. “We can never prove that is not the case, so I think it’s fair to say that most physicists don’t worry too much about this.”
   Nature doi:10.1038/nature.2015.18255
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 30-08-2015, 11:28:58
Ovaj poslednji ‘freedom-of-choice loophole’ se lepo slaže sa drugim tvojim skorašnjim postom o obilju studija koje niko ne može da reprodukuje.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 30-08-2015, 12:51:05
Da, to sam i ja pomislio kačeći ga. Al, opet, neka ga ovde.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 26-10-2015, 11:29:04
'Zeno effect' verified: Atoms won't move while you watch (http://news.cornell.edu/stories/2015/10/zeno-effect-verified-atoms-wont-move-while-you-watch)



Quote
One of the oddest predictions of quantum theory – that a system can’t change while you’re watching it – has been confirmed in an experiment by Cornell physicists. Their work opens the door to a fundamentally new method to control and manipulate the quantum states of atoms and could lead to new kinds of sensors.
The experiments were performed in the Utracold (http://ultracold.lassp.cornell.edu/) Lab of Mukund Vengalattore, assistant professor of physics, who has established Cornell’s first program to study the physics of materials cooled to temperatures as low as .000000001 degree above absolute zero. The work is described in the Oct. 2 issue of the journal Physical Review Letters (http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.140402)
Graduate students Yogesh Patil and Srivatsan Chakram created and cooled a gas of about a billion Rubidium atoms inside a vacuum chamber and suspended the mass between laser beams. In that state the atoms arrange in an orderly lattice just as they would in a crystalline solid. But at such low temperatures the atoms can “tunnel” from place to place in the lattice. The famous Heisenberg uncertainty principle says that position and velocity of a particle are related and cannot be simultaneously measured precisely. Temperature is a measure of a particle’s motion. Under extreme cold velocity is almost zero, so there is a lot of flexibility in position; when you observe them, atoms are as likely to be in one place in the lattice as another.
The researchers demonstrated that they were able to suppress quantum tunneling merely by observing the atoms. This so-called “Quantum Zeno effect,” named for a Greek philosopher, derives from a proposal in 1977 by E.C. George Sudarshan and Baidyanath Misra at the University of Texas, Austin, who pointed out that the weird nature of quantum measurements allows, in principle, for a quantum system to be “frozen” by repeated measurements.
Previous experiments have demonstrated the Zeno effect with the “spins” of subatomic particles. “This is the first observation of the Quantum Zeno effect by real space measurement of atomic motion,” Vengalattore said. “Also, due to the high degree of control we’ve been able to demonstrate in our experiments, we can gradually ‘tune’ the manner in which we observe these atoms. Using this tuning, we’ve also been able to demonstrate an effect called ‘emergent classicality’ in this quantum system.” Quantum effects fade, and atoms begin to behave as expected under classical physics.
The researchers observed the atoms under a microscope by illuminating them with a separate imaging laser. A light microscope can’t see individual atoms, but the imaging laser causes them to fluoresce, and the microscope captured the flashes of light. When the imaging laser was off, or turned on only dimly, the atoms tunneled freely. But as the imaging beam was made brighter and measurements made more frequently, the tunneling reduced dramatically.
“This gives us an unprecedented tool to control a quantum system, perhaps even atom by atom,” said Patil, lead author of the paper. Atoms in this state are extremely sensitive to outside forces, he noted, so this work could lead to the development of new kinds of sensors.
The experiments were made possible by the group’s invention of a novel imaging technique (https://journals.aps.org/pra/abstract/10.1103/PhysRevA.90.033422) that made it possible to observe ultracold atoms while leaving them in the same quantum state. “It took a lot of dedication from these students and it has been amazing to see these experiments be so successful,” Vengalattore said. “We now have the unique ability to control quantum dynamics purely by observation.”
The popular press has drawn a parallel with the “weeping angels” depicted in the “Dr. Who” television series – alien creatures who look like statues and can’t move as long as you’re looking at them. There may be some sense to that. In the quantum world, the folk wisdom really is true: “A watched pot never boils.”
The research was supported by the Army Research Office, the Defense Advanced Research Projects Agency under its QuASAR program and the National Science Foundation.
Recent Ph.D. graduate Chakram is now at the University of Chicago.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Ukronija on 26-10-2015, 11:36:24
Pa da ali zasto? Zasto??  :lol:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 26-10-2015, 11:49:48
Šta zašto? Zašto se sistem ne menja dok ga gledaš? Pa dosta je to podrobno objašnjeno u kvantnoj teoriji, ovo je samo eksperimentalna potvrda te teorije (ne ni prva po redu). E, sad, pošto niko od nas nije kvantni fizičar, onda ne treba očekivati da nam je odmah i intuitivno jasno zašto. Evo nekih pojednostavljenih pojašnjenja napravljenih za nas, laike:



http://youtu.be/7u_UQG1La1o (http://youtu.be/7u_UQG1La1o)


Quote
Let me explain this for the clueless/confused: When he says "observe" he doesn't mean a human/conscious being observing. In order to observe, you have to, directly or indirectly, interact with the thing you're observing, right? The machine is interacting with the electron due to that observing and that is what is collapsing the "wave form of the electron" into the "particle form of the electron". By observing/not observing the electron and thus interacting with the electron you are forcing it to make up it's mind of whether it's here or there. The wave is a wave of the probability of finding the electron there so when you are observing/interacting with the electron it is more likely to be found at the peaks of the wave and less likely to be found at the troughs of the wave.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Ukronija on 26-10-2015, 13:43:10
Daj, ne zezaj, Meho. Nijedna teorija dosad nije objasnila zašto. Samo - kako.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 26-10-2015, 14:00:28
Nisam siguran da razumem šta hoćeš da kažeš. Misliš na neko metafizičko "zašto"? Na primer, Njutnova teorija objašnjava gravitaciono privlačenje između tela koja imaju masu i pokazuje "zašto" jabuka padne sa drveta, pa posle nje idu i detaljnije teorije koje pojašnjavaju prirodu gravitacionog polja, sa sve krunom u vidu Higsovog bozona (kvantne čestice koja "nosi" masu) i što se tiče "zašto" u nekom praktičnom smislu tu nemamo mnogo nedoumica jer ove teorije objašnjavaju uzrok i posledicu. Ali neko može da pita "A ZAŠTO je to baš tako? Zašto su to baš te vrednosti (npr. snaga gravitacionog privlačenja opada sa kvadratom razdaljine), zašto se gravitaciona sila po telu raspoređuje na baš ovakav način itd." i to su legitimna pitanja koja dalje teorije mogu ili ne moraju da razjasne. No, nisam siguran da li je to pitanje koje ti tu postavljaš ili pitaš o nekakvom prauzroku itd. Jer na to drugo pitanje nisam siguran da postoji jednoznačan odgovor. Ima ono antropičko načelo: kosmos je ovakav kakav je jer mi, ovakvi kakvi smo možemo tako da ga percipiramo. Nekom drugom, sa drugačijom fiziologijom je kosmos drugačiji.

U tom smislu, kvantna mehanika je takva kakva je jer je naša percepcija takva kakva je, koristimo određene metode da posmatramo kvantne fenomene i vezani smo za njih već svojom fiziologijom (da smo svi slepi, recimo, svetlost nam verovatno ne bi bila principijelni metod istraživanja fenomena).

Malo konfuzno odgovaram jer nisam siguran šta je pitanje, jelte.  :lol: Hoću reći, kvantna teorija daje dovoljno dobro "zašto" u smislu da kaže "pretpostavka je da ovaj sistem ovako funkcioniše jer su ovo njegova fundamentalna pravila" a onda se to eksperimentalno dokazuje. No, pitanje "zašto" su to fundamentalna pravila sistema (zašto logaritamske funkcije opisuju način formiranja puževe kućice, zašto oblici snežnih pahuljica prate fraktalna pravila) mi deluje kao pitanje iz domena metafizike i kao da traži prauzrok koji svemu daje viši, čak duhovniji smisao, a nisam siguran da se ove druge nauke smeju time baviti.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Ukronija on 26-10-2015, 16:07:44
domena metafizike i kao da traži prauzrok koji svemu daje viši, čak duhovniji smisao, a nisam siguran da se ove druge nauke smeju time baviti.

Pa naravno da smeju. Moraju. Krajnja misija svih nauka bi trebalo da bude odgovor na fundamentalno pitanje - zašto, kroz objašnjenje - kako. Ne staje se kod - kako, pa se to kako menja sa svakim uočavanjem novog fenomena, ili se novi fenomen jednostavno nazove - izuzetkom. Ja shvatila da je nauka smešna još kada mi je u osnovnoj školi pružila model atoma. I ja sada treba da verujem da elektroni kruže oko jezgra od protona i neutrona zato što im se tako sviđa? I dokle ide to rasitnjavanje čestica? Do tehnikvarkova (više nije ni Higsov bozon)? :lol:

Ako ima nečeg u intuitivnom shvatanju sveta, meni je moje uvek govorilo da je sve što, kao, znamo jednostavno tragično pogrešno. Kao, osmislili smo fiziku, objasnili fenomene, izašli malo u svemir, i cela fizika na zemlji pala je u vodu. Pa smo onda smislili paralelnu fiziku koja važi za svemir. Aha. Ili ima beskonačno mnogo fizika, ili postoji jedna. Dve, jedna na zemlji i jedna u ostatku svemira su izuzetno egocentričan koncept.

To je isto kao kada ljudi u potrazi za životom na drugim planetama traže planete sa vodom, a intuitivno mi govori da su različiti sistemi mogli da razviju takve oblike "života" koje ne samo da ne možemo da pojmimo, već se nalaze u pet, šest, pedeset dimenzija. A isto tako kao što su bića na zemlji "našla način" da koriste kiseonik i da se u njihovim telima odvija reakcija i korišćenje tog kiseonika za životne procese, tako su i druga bića tamo negde mogla da "pronađu" način da udišu metan, azot, pesak ili da ne udišu ništa. Mislim, ubi nas ego.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 26-10-2015, 17:09:39
Ne znam, nisam dovoljno filozofije nauke pročitao da bih ovde smeo da polemišem na tako visokom nivou. Ono malo epistemologije što sam u prolazu zakačio raspravlja o znanju i njegovom odnosu prema istini ali, Rasel pogotovo, se najviše bavio kvalitetom znanja (da li nešto "znaš" ako ne znaš da ga diskurzivno objasniš itd.) Ovo što ti pričaš, opet ću reći, tu već zalazimo u metafizičke vode i pošto je dobar deo prirodnih nauka koje poznajem zasnovan na određenom broju aksiomatskih načela, mislim da one sebi ne stavljaju u opis posla iznalaženje apsolutne istine. Već, ako smem ja da ovako superlaički "objašnjavam" nauku, najboljeg opisa stanja stvari uz dostupna sredstva. A podrazumeva se da će se taj opis menjati kako sredstva postaju iterativno bolja. Opet, aksiomi se uglavnom ne menjaju niti se (uobičajeno) traži da se oni obrazlažu, oni se doživljavaju kao ti neki fundamentalni principi naše percepcije stvarnosti i verovatno ne možemo da izađemo iz njih.

U tom smislu, nisam siguran šta želiš da kažeš ovim za kruženje elektrona oko jezgra. Postoje precizni matematički modeli kojim se opisuje atom i ti modeli uglavnom nisu zasnovani na planetarnom modelu (on se u osnovnoj i srednjoj školi koristi kao aproksimacija dovoljna za taj nivo rasprave, ali niko se ne pravi kao da je to najnoviji, najsvežiji naučni model) već govore o dualnoj, čestično-talasnoj prirodi ovog fenomena i tu kvantni fenomeni dolaze do izražaja. Uvođenjem Šredingerovog modela "zvanično" je napušten Njutnov model kojim je do tada aproksimativno opisivana priroda stvari na tom nivou i pošto su kvantnomehanički fenomeni po prirodi različiti od makromehaničkih, poseglo se za diferencijalnim računom. Naravno, što se dublje išlo u istraživanje kvantnih modela, stvari su sve složenije ali, fundamentalno Šredingerove postavke još uvek važe i eksperimentalno se potvrđuju. Naravno da će, možda, sa daljim istraživanjem doći do toga da na nekom još sitnijem nivou više ne važi šredingerovsko opisivanje i shvatanje stanja, kao što je njegovo shvatanje ukinulo njutnovsko na svom nivou, ali ja zaista ne znam ništa o tome da bih mogao da raspravljam.

Takođe, nisam uopšte siguran ni šta misliš kada kažeš da u svemiru važi jedna fizika a na Zemlji druga. O čemu pričamo? Podela na kvantnu i klasičnu mehaniku postoji ali ona važi i u svemiru i na Zemlji i tiče se talasnih svojstava čestica koje dolaze do izražaja tek kada imamo veoma male čestice, ali ovo ne znači da čestice veličine mene ili tebe nemaju svojstva talasa, samo da su ta svojstva, ako smem ovako ultralaički da se izrazim, ekstremno neizražena  :lol: :lol: :lol: Dakle, ne znam na koje dve fizike misliš. Možeš da pojasniš?

I, ne mislim da je "ego" u pitanju kada pričamo o tome da mi život prevashodno tražimo u vodi i u procesu oskidacije, već opet pre to antropičko načelo: ako je sve što znamo o životu došlo sa ove planete, onda je logično da ćemo u okvirima modela koje razumemo i umemo da objasnimo raspravljati i o životu negde tamo. Naravno, naučna fantastika ali i klasična kosmologija uveliko raspravljaju o drugim oblicima života, ali postoje određeni modeli koji se ponavljaju u vrlo različitim okruženjima na Zemlji pa ima smisla da smatramo da bi mogli statistički biti solidno zastupljeni i izvan Zemlje.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Ukronija on 26-10-2015, 17:37:05
O čemu pričamo?

Ej, nemam pojma, Meho. Ja reko da podržim topik, da Zorannah ne dobije primat na forumu.  :lol:

Smisliću odgovor u narednim danima.  xremyb
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 26-10-2015, 17:40:51
Pa, dobro, ako je jedna uspešna fešn blogerka podsticaj da se ovde priča o fizici, onda je sve u redu i Alah je dobro obavio svoj posao  :lol:
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: milan on 27-10-2015, 09:56:54
OBOZAVAM Mehove "ultralaicke" postove!!!! :)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Ukronija on 27-10-2015, 13:15:05
Aha.  :lol: Pogotovo ovaj deo:

Podela na kvantnu i klasičnu mehaniku postoji ali ona važi i u svemiru i na Zemlji i tiče se talasnih svojstava čestica koje dolaze do izražaja tek kada imamo veoma male čestice, ali ovo ne znači da čestice veličine mene ili tebe nemaju svojstva talasa, samo da su ta svojstva, ako smem ovako ultralaički da se izrazim, ekstremno neizražena  :lol: :lol: :lol:

 xcheers
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 17-11-2015, 11:30:26
Evo još malo kvantnih zavrzlama. Kvantna upletenost (da li se ovako prevodi Quantum Entanglement?) preživljava i prelazak horizonta događaja, pokazuju eksperimenti, koji, naravno, nisu rađeni putem ulaska u crnu rupu, već u laboratoriji, simulirajući uslove crne rupe kolko god se najbolje moglo. Tekst je pun grafikona, slika i videa pa samo ostavljam link.



Gravity's Most Extreme Effects Can Now Be Tested In A Laboratory (http://www.forbes.com/sites/startswithabang/2015/11/12/gravitys-most-extreme-effects-can-now-be-tested-in-a-laboratory/)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 30-06-2016, 08:17:55
Ja ovo ništa ne razumem. Ima li neko ko ovo može da rastumači primatu mog tipa? Mislim, dok priča o jezgrima atoma i njihovom obliku, u redu je. Ali onda kada lakonski ustvrdi da to znači da možda nikada nećemo ovladati putovanjem kroz vreme (u nekom drugom smeru od uobičajenog, jelte) - tu me potpuno izgubi. WTF?


 Physicists just confirmed a pear-shaped nucleus, and it could ruin time travel forever  (http://www.sciencealert.com/physicists-just-discovered-a-new-nucleus-shape-and-it-could-ruin-our-hopes-of-time-travel)


Quote
Physicists have confirmed the existence of a new form of atomic nuclei, and the fact that it’s not symmetrical challenges the fundamental theories of physics that explain our Universe.
But that's not as bad as it sounds, because the discovery could help scientists solve one of the biggest mysteries in theoretical physics - where is all the dark matter? (http://www.sciencealert.com/how-we-recreated-the-early-universe-in-the-laboratory) - and could also explain why travelling backwards in time (http://www.sciencealert.com/watch-3-simple-ways-to-time-travel) might actually be impossible.
"We've found these nuclei literally point towards a direction in space. This relates to a direction in time, proving there's a well-defined direction in time and we will always travel from past to present," Marcus Scheck from the University of the West of Scotland told Kenneth MacDonald at BBC News. (http://www.bbc.co.uk/news/uk-scotland-36597142?utm_source=fark&utm_medium=website&utm_content=link)
So let’s back up here, because to understand this new form of atomic nuclei, you have to get to know the old ones first. Until recently, it was established that the nuclei of atoms could be one of just three shapes - spherical, discus, or rugby ball.
These shapes are formed by the distribution of electrical charge within a nucleus (https://books.google.com.au/books?id=yGdGbzlA6AQC&pg=PA43&lpg=PA43&dq=spherical,+discus,+or+rugby+ball+atomic+nuclei&source=bl&ots=wHOBw-D4Sy&sig=AP92kpkMy0Ya8N3RDTZyLV8ab0M&hl=en&sa=X&ved=0ahUKEwjP99bpm8fNAhWHE5QKHYkRAy8Q6AEIIzAB#v=onepage&q=spherical%2C%20discus%2C%20or%20rugby%20ball%20atomic%20nuclei&f=false), and are dictated by the specific combinations of protons and neutrons in a certain type of atom, whether it’s a hydrogen atom, a zinc atom, or a complex isotope created in a lab.
The common factor across all three shapes is their symmetry, and this marries nicely with a theory in particle physics known as CP-Symmetry (https://en.wikipedia.org/wiki/CP_violation#CP-symmetry). CP-symmetry is the combination of two symmetries that are thought to exist in the Universe: C-Symmtery and P-Symmetry.
C-Symmetry (https://en.wikipedia.org/wiki/C-symmetry), also known as charge symmetry,  states that if you flip an atomic charge to its opposite, the physics of that atom should still be the same. So if we take a hydrogen atom and an anti-hydrogen atom (http://www.sciencealert.com/scientists-have-measured-the-force-that-makes-holds-antimatter-together-for-the-first-time) and mess with them, both should respond in identical ways, even though they have opposite charges.
P-Symmetry, also known as Parity (http://www.britannica.com/science/parity-particle-physics), states that the the spatial coordinates describing a system can be inverted through the point at the origin, so that x, y, and z are replaced with −x, −y, and −z.
"Your left hand and your right hand exhibit P-Symmetry from one another: if you point your thumb up and curl your fingers, your left and right hands mirror one another," Ethan Siegel from It Starts With a Bang explains (http://www.forbes.com/sites/startswithabang/2015/12/31/why-are-we-made-of-matter-and-not-antimatter/#2adba508790a).
CP-Symmetry is a combination of both of these assumptions. "In particle physics, if you have a particle spinning clockwise and decaying upwards, its antiparticle should spin counterclockwise and decay upwards 100 percent of the time if CP is conserved," says Siegel (http://www.forbes.com/sites/startswithabang/2015/12/31/why-are-we-made-of-matter-and-not-antimatter/#2adba508790a). "If not, CP is violated.”
The possibility that the Universe could actually violate both C-Symmetry and CP-Symmetry is one of the conditions that have been proposed to explain the mystery of antimatter in the Universe (http://www.sciencealert.com/how-we-recreated-the-early-universe-in-the-laboratory). But proving that would mean the Standard Model of Physics needs a serious rethink.
According to the laws of physics, at the time of the Big Bang, equal amounts of matter and antimatter had to have been created, but now, billions of years later, we’re surrounded by heaps of matter (solid, liquid, gas, and plasma), but there appears to be almost no naturally occurring antimatter.
"This is a puzzling feature, as the theory of relativistic quantum mechanics suggests we should have equal amounts of the two," mathematician Gianluca Sarri from Queen's University Belfast in the UK writes for The Conversation (http://www.sciencealert.com/how-we-recreated-the-early-universe-in-the-laboratory). "In fact, no current model of physics can explain the discrepancy."
Okay, so back to our atomic nuclei shapes. Most of our fundamental theories of physics are based on symmetry, so when physicists at CERN discovered an asymmetrical pear-shaped nucleus in the isotope Radium-224 back in 2013 (https://home.cern/about/updates/2013/05/first-observations-short-lived-pear-shaped-atomic-nuclei), it was a bit of a shock, because it showed that nuclei could have more mass at one end than the other.
Now, three years later, the find has been confirmed by a second study (http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.112503), which has shown that the nucleus of the isotope Barium-144 is also asymmetrical and pear-shaped.
"[T]he protons enrich in the bump of the pear and create a specific charge distribution in the nucleus," Scheck told the BBC (http://www.bbc.co.uk/news/uk-scotland-36597142?utm_source=fark&utm_medium=website&utm_content=link). "This violates the theory of mirror symmetry and relates to the violation shown in the distribution of matter and antimatter in our Universe."
While physicists have suspected that Barium-144 has a pear-shaped nucleus for some time now, Scheck and his team finally figured out how to directly observe that, and it turns out its distortion is even more pronounced than predicted.
So what does all of this have to do with time travel? It's a pretty out-there hypothesis, but Scheck says that this uneven distribition of mass and charge causes Barium-144's nucleus to 'point' in a certain direction in spacetime, and this bias could explain why time seems to only want to go from past to present, and not backwards (http://www.sciencealert.com/scientists-propose-a-mirror-universe-where-time-moves-backwards), even if the laws of physics don't care  (http://www.sciencealert.com/physicists-just-found-a-link-between-dark-energy-and-the-arrow-of-time)which way it goes (http://www.sciencealert.com/physicists-just-found-a-link-between-dark-energy-and-the-arrow-of-time).
Of course, there's no way of proving that without further evidence, but the discovery is yet another indication that the Universe might not be as symmetrical as the Standard Model of Physics needs it to be, and proving that could usher us into a whole new era of theoretical physics.
The study has been published in Phyiscal Review Letters (http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.112503), and can be accessed for free at arXiv.org (http://arxiv.org/pdf/1602.01485v1.pdf).
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 23-09-2016, 08:26:26
 Quantum teleportation was just achieved over more than 7 km of city fibre (http://www.sciencealert.com/quantum-teleportation-was-just-achieved-over-7-km-of-cable)


Quote
  Quantum teleportation just moved out of the lab and into the real world, with two independent teams of scientists successfully sending quantum information across several kilometres of optical fibre networks in Calgary, Canada, and Hefei, China.
The experiments show that not only is quantum teleportation very much real, it's also feasible technology that could one day help us build unhackable quantum communication systems that stretch across cities and maybe even continents.
Quantum teleportation relies on a strange phenomenon called quantum entanglement (http://www.sciencealert.com/physicists-just-quantum-entangled-10-photon-pairs-and-set-a-new-world-record). Basically, quantum entanglement means that two particles are inextricably linked, so that measuring the state of one immediately affects the state of the other, no matter how far apart the two are - which led Einstein to call entanglement "spooky action at a distance (http://www.sciencealert.com/physicists-just-quantum-entangled-10-photon-pairs-and-set-a-new-world-record)".
Using that property, quantum teleportation allows the quantum state of one particle to be transferred to its partner, no matter the distance between the two, without anything physical passing between them.
That's not like the teleportation you see in sci-fi shows like Star Trek - only information can be sent via quantum teleportation, not people.
What it is, though, is a great way to create an unhackable, totally encrypted form of communication - just imagine receiving information that can only be interpreted once you know the state of your entangled particle.
In the latest experiments, both published in Nature Photonics (here (http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2016.180.html) and here (http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2016.179.html)), the teams had slightly different set-ups and results. But what they both had in common is the fact that they teleported their information across existing optical fibre networks - which is important if we ever want to build useable quantum communication systems.
In fact, quantum teleportation has been achieved over greater distances (http://www.sciencealert.com/a-new-quantum-teleportation-distance-record-has-been-set) in the past - in 2012, researchers from Austria set a record by teleporting information across 143 km of space using lasers (http://www.nature.com/nature/journal/v489/n7415/full/nature11472.html), but that technology isn't as useful for practical networks as optical fibre.
To understand the experiments, Anil Ananthaswamy over at  (https://www.newscientist.com/article/2106326-quantum-teleportation-over-7-kilometres-of-cables-smashes-record/)New Scientist (https://www.newscientist.com/article/2106326-quantum-teleportation-over-7-kilometres-of-cables-smashes-record/) nicely breaks it down like this: picture three people involved - Alice, Bob, and Charlie.
Alice and Bob want to share cryptographic keys, and to do that, they need Charlie's help. Alice sends a particle to Charlie, while Bob entangles two particles and sends just one of them to Charlie.
Charlie then measures the two particles he's received from each of them, so that they can no longer be differentiated - and that results in the quantum state of Alice's particle being transferred to Bob's entangled particle.
So basically, the quantum state of Alice's particle eventually ends up in Bob's particle, via a way station in the form of Charlie.
The Canadian experiment followed this same process, and was able to send quantum information over 6.2 km of Calgary's fibre optic network that's not regularly in use.
"The distance between Charlie and Bob, that's the distance that counts," lead researcher of the Canadian experiment, Wolfgang Tittel, from the University of Calgary in Alberta, told  (http://www.sciencealert.com/%3Cp%3EIt%27s%20getting%20real.%3C/p%3E%20%3Chr%20id=%22system-readmore%22%20/%3E%20%3Cp%3EQuantum%20teleportation%20just%20moved%20out%20of%20the%20lab%20and%20into%20the%20real%20world,%20with%20two%20independent%20teams%20of%20scientists%20successfully%20sending%20quantum%20information%20across%20several%20kilometres%20of%20optical%20fibre%20networks%20in%20Calgary,%20Canada,%20and%20Hefei,%20China.%3C/p%3E%20%3Cp%3EThe%20experiments%20show%20that%20not%20only%20is%20quantum%20teleportation%20very%20much%20real,%20it%27s%20also%20feasible%20technology%20that%20could%20one%20day%20help%20us%20build%20unhackable%20quantum%20communication%20systems%20that%20stretch%20across%20cities%20and%20maybe%20even%20continents.%3C/p%3E%20%3Cp%3EQuantum%20teleportation%20relies%20on%20the%20strange%20phenomenon%20called%20quantum%20entanglement. Basically,%20quantum%20entanglement%20means%20that%20two%20particles%20are%20inextricably%20linked,%20so%20that%20measuring%20the%20state%20of%20one%20immediately%20affects%20the%20state%20of%20the%20other,%20no%20matter%20how%20far%20apart%20the%20two%20are%20-%20which%20led%20Einstein%20to%20call%20entanglement%20%22spooky%20action%20at%20a%20distance%22.%3C/p%3E%20%3Cp%3EUsing%20that%20property,%20quantum%20teleportation%20allows%20the%20quantum%20state%20of%20one%20particle%20to%20be%20transferred%20to%20its%20partner,%20no%20matter%20the%20distance%20between%20the%20two,%20without%20anything%20physical%20passing%20between%20them.%3C/p%3E%20%3Cp%3EThat%27s%20not%20like%20the%20teleportation%20you%20see%20in%20sci-fi%20shows%20like %3Cem%3EStar%20Trek %3C/em%3E-%20only%20information%20can%20be%20sent%20via%20quantum%20teleportation,%20not%20people.%3C/p%3E%20%3Cp%3EWhat%20it %3Cem%3Eis%3C/em%3E,%20though,%20is%20a%20great%20way%20to%20create%20an%20unhackable,%20totally%20encrypted%20form%20of%20communication%20-%20just%20imagine%20receiving%20information%20that%20can%20only%20be%20interpreted%20once%20you%20know%20the%20state%20of%20your%20entangled%20particle.%3C/p%3E%20%3Cp%3EIn%20the%20latest%20experiments,%20both%20published%20in %3Cem%3ENature%20Photonics, %3C/em%3Ethe%20teams%20had%20slightly%20different%20set-ups%20and%20results.%20But%20what%20they%20both%20had%20in%20common%20is%20the%20fact%20that%20they%20teleported%20their%20information%20across%20optical%20fibre%20-%20which%20is%20important%20if%20we%20ever%20want%20to%20build%20useable%20quantum%20communication%20networks.%3C/p%3E%20%3Cp%3EIn%20fact,%20quantum%20teleportation%20has%20been%20achieved%20over%20greater%20distances%20in%20the%20past%20-%20in%202012,%20researchers%20from%20Austria%20set%20a%20record%20by%20teleporting%20information%20across%20143%20km%20using%20lasers,%20but%20that%20technology%20isn%27t%20as%20useful%20for%20practical%20networks%20as%20optical%20fibre.%3C/p%3E%20%3Cp%3ETo%20understand%20the%20experiments,%20%3Ca%20href=%22https:/www.newscientist.com/article/2106326-quantum-teleportation-over-7-kilometres-of-cables-smashes-record/%22%3EAnil%20Ananthaswamy%20over%20at%20%3C/a%3E%3Cem%3E%3Ca%20href=%22https:/www.newscientist.com/article/2106326-quantum-teleportation-over-7-kilometres-of-cables-smashes-record/%22%3ENew%20Scientist%3C/a%3E %3C/em%3Enicely%20breaks%20it%20down%20like%20this:%20picture%20three%20people%20involved,%20Alice,%20Bob,%20and%20Charlie. %3C/p%3E%20%3Cp%3EAlice%20and%20Bob%20want%20to%20share%20cryptographic%20keys,%20and%20to%20do%20that,%20they%20need%20Charlie%27s%20help.%20Alice%20sends%20a%20particle%20to%20Charlie,%20while%20Bob%20entangles%20two%20particles%20and%20sends%20just%20one%20of%20them%20to%20Charlie.%3C/p%3E%20%3Cp%3ECharlie%20then%20measures%20the%20two%20particles%20he%27s%20received%20from%20each%20of%20them,%20so%20that%20they%20can%20no%20longer%20be%20differentiated%20-%20and%20that%20results%20in%20the%20quantum%20state%20of%20Alice%27s%20particle%20being%20transferred%20to%20Bob%27s%20entangled%20particle.%3C/p%3E%20%3Cp%3ESo%20basically,%20the%20quantum%20state%20of%20Alice%27s%20particle%20eventually%20ends%20up%20in%20Bob%27s%20particle,%20via%20a%20way%20station%20in%20the%20form%20of%20Charlie.%3C/p%3E%20%3Cp%3EThe%20Canadian%20experiment%20followed%20this%20same%20process,%20and%20was%20able%20to%20send%20their%20quantum%20information%20over%206.2%20km%20of%20Calgary%27s%20fibre%20optic%20network%20that%27s%20not%20regularly%20in%20use.%3C/p%3E%20%3Cp%3E%22The%20distance%20between%20Charlie%20and%20Bob,%20that%27s%20the%20distance%20that%20counts,%22%20lead%20researcher%20of%20the%20Canadian%20experiment,%20Wolfgang%20Tittel,%20from%20the%20University%20of%20Calgary%20in%20Alberta,%20told%20%3Cem%3ENew%20Scientist. %3C/em%3E%22We%20have%20shown%20that%20this%20works%20across%20a%20metropolitan%20fibre%20network,%20over%206.2%20kilometres,%20as%20the%20crow%20flies.%22%3C/p%3E%20%3Cp%3EThe%20Chinese%20researchers%20were%20able%20to%20extend%20their%20teleportation%20further,%20over%20a%2012.5%20km%20area,%20but%20they%20had%20a%20slightly%20different%20set%20up.%20It%20was%20Charlie%20in%20the%20middle%20who%20created%20the%20entangled%20particles%20and%20sent%20one%20to%20Bob,%20instead%20of%20the%20other%20way%20around.%3C/p%3E%20%3Cp%3EThis%20could%20work%20best%20for%20a%20quantum%20network%20where%20a%20central%20quantum%20computer%20%28Charlie%29%20communicates%20with%20lots%20of%20Alice%27s%20and%20Bob%27s%20around%20a%20city.%20But%20the%20Calgary%20model%20could%20spread%20even%20greater%20distances,%20because%20Bob%20could%20work%20like%20a%20quantum%20repeater,%20sending%20the%20information%20further%20and%20further%20down%20the%20line.%3C/p%3E%20%3Cp%3EThe%20downside%20to%20both%20experiments%20was%20that%20they%20couldn%27t%20send%20very%20much%20information.%20The%20Calgary%20experiment%20was%20the%20fastest,%20managing%20to%20send%2017%20photons%20a%20minute. %3C/p%3E%20%3Cp%3EAnd%20while%20many%20people%20assume%20that%20quantum%20teleportation%20would%20result%20in%20instantaneous%20communication,%20in%20reality,%20decrypting%20the%20quantum%20state%20of%20the%20entangled%20particle%20requires%20a%20key,%20that%20needs%20to%20be%20sent%20via%20regular%20slow%20communication%20-%20so%20quantum%20teleportation%20wouldn%27t%20actually%20be%20any%20faster%20than%20the%20internet%20we%20already%20have,%20just%20more%20secure.%3C/p%3E%20%3Cp%3EBut%20the%20fact%20that%20both%20teams%20were%20able%20to%20use%20existing%20telecommunications%20infrastructure%20to%20achieve%20such%20long-distance%20quantum%20teleportation%20at%20all%20is%20a%20huge%20deal%20-%20and%20something%20that%20hasn%27t%20been%20done%20outside%20of%20the%20lab%20before.%3C/p%3E%20%3Cp%3EIt%27s%20going%20to%20take%20a%20lot%20more%20tweaking%20and%20investigation%20before%20it%27s%20something%20that%20we%20can%20use%20in%20our%20daily%20lives,%20but%20we%27re%20definitely%20getting%20closer.%3C/p%3E)New Scientist (http://www.sciencealert.com/%3Cp%3EIt%27s%20getting%20real.%3C/p%3E%20%3Chr%20id=%22system-readmore%22%20/%3E%20%3Cp%3EQuantum%20teleportation%20just%20moved%20out%20of%20the%20lab%20and%20into%20the%20real%20world,%20with%20two%20independent%20teams%20of%20scientists%20successfully%20sending%20quantum%20information%20across%20several%20kilometres%20of%20optical%20fibre%20networks%20in%20Calgary,%20Canada,%20and%20Hefei,%20China.%3C/p%3E%20%3Cp%3EThe%20experiments%20show%20that%20not%20only%20is%20quantum%20teleportation%20very%20much%20real,%20it%27s%20also%20feasible%20technology%20that%20could%20one%20day%20help%20us%20build%20unhackable%20quantum%20communication%20systems%20that%20stretch%20across%20cities%20and%20maybe%20even%20continents.%3C/p%3E%20%3Cp%3EQuantum%20teleportation%20relies%20on%20the%20strange%20phenomenon%20called%20quantum%20entanglement. Basically,%20quantum%20entanglement%20means%20that%20two%20particles%20are%20inextricably%20linked,%20so%20that%20measuring%20the%20state%20of%20one%20immediately%20affects%20the%20state%20of%20the%20other,%20no%20matter%20how%20far%20apart%20the%20two%20are%20-%20which%20led%20Einstein%20to%20call%20entanglement%20%22spooky%20action%20at%20a%20distance%22.%3C/p%3E%20%3Cp%3EUsing%20that%20property,%20quantum%20teleportation%20allows%20the%20quantum%20state%20of%20one%20particle%20to%20be%20transferred%20to%20its%20partner,%20no%20matter%20the%20distance%20between%20the%20two,%20without%20anything%20physical%20passing%20between%20them.%3C/p%3E%20%3Cp%3EThat%27s%20not%20like%20the%20teleportation%20you%20see%20in%20sci-fi%20shows%20like %3Cem%3EStar%20Trek %3C/em%3E-%20only%20information%20can%20be%20sent%20via%20quantum%20teleportation,%20not%20people.%3C/p%3E%20%3Cp%3EWhat%20it %3Cem%3Eis%3C/em%3E,%20though,%20is%20a%20great%20way%20to%20create%20an%20unhackable,%20totally%20encrypted%20form%20of%20communication%20-%20just%20imagine%20receiving%20information%20that%20can%20only%20be%20interpreted%20once%20you%20know%20the%20state%20of%20your%20entangled%20particle.%3C/p%3E%20%3Cp%3EIn%20the%20latest%20experiments,%20both%20published%20in %3Cem%3ENature%20Photonics, %3C/em%3Ethe%20teams%20had%20slightly%20different%20set-ups%20and%20results.%20But%20what%20they%20both%20had%20in%20common%20is%20the%20fact%20that%20they%20teleported%20their%20information%20across%20optical%20fibre%20-%20which%20is%20important%20if%20we%20ever%20want%20to%20build%20useable%20quantum%20communication%20networks.%3C/p%3E%20%3Cp%3EIn%20fact,%20quantum%20teleportation%20has%20been%20achieved%20over%20greater%20distances%20in%20the%20past%20-%20in%202012,%20researchers%20from%20Austria%20set%20a%20record%20by%20teleporting%20information%20across%20143%20km%20using%20lasers,%20but%20that%20technology%20isn%27t%20as%20useful%20for%20practical%20networks%20as%20optical%20fibre.%3C/p%3E%20%3Cp%3ETo%20understand%20the%20experiments,%20%3Ca%20href=%22https:/www.newscientist.com/article/2106326-quantum-teleportation-over-7-kilometres-of-cables-smashes-record/%22%3EAnil%20Ananthaswamy%20over%20at%20%3C/a%3E%3Cem%3E%3Ca%20href=%22https:/www.newscientist.com/article/2106326-quantum-teleportation-over-7-kilometres-of-cables-smashes-record/%22%3ENew%20Scientist%3C/a%3E %3C/em%3Enicely%20breaks%20it%20down%20like%20this:%20picture%20three%20people%20involved,%20Alice,%20Bob,%20and%20Charlie. %3C/p%3E%20%3Cp%3EAlice%20and%20Bob%20want%20to%20share%20cryptographic%20keys,%20and%20to%20do%20that,%20they%20need%20Charlie%27s%20help.%20Alice%20sends%20a%20particle%20to%20Charlie,%20while%20Bob%20entangles%20two%20particles%20and%20sends%20just%20one%20of%20them%20to%20Charlie.%3C/p%3E%20%3Cp%3ECharlie%20then%20measures%20the%20two%20particles%20he%27s%20received%20from%20each%20of%20them,%20so%20that%20they%20can%20no%20longer%20be%20differentiated%20-%20and%20that%20results%20in%20the%20quantum%20state%20of%20Alice%27s%20particle%20being%20transferred%20to%20Bob%27s%20entangled%20particle.%3C/p%3E%20%3Cp%3ESo%20basically,%20the%20quantum%20state%20of%20Alice%27s%20particle%20eventually%20ends%20up%20in%20Bob%27s%20particle,%20via%20a%20way%20station%20in%20the%20form%20of%20Charlie.%3C/p%3E%20%3Cp%3EThe%20Canadian%20experiment%20followed%20this%20same%20process,%20and%20was%20able%20to%20send%20their%20quantum%20information%20over%206.2%20km%20of%20Calgary%27s%20fibre%20optic%20network%20that%27s%20not%20regularly%20in%20use.%3C/p%3E%20%3Cp%3E%22The%20distance%20between%20Charlie%20and%20Bob,%20that%27s%20the%20distance%20that%20counts,%22%20lead%20researcher%20of%20the%20Canadian%20experiment,%20Wolfgang%20Tittel,%20from%20the%20University%20of%20Calgary%20in%20Alberta,%20told%20%3Cem%3ENew%20Scientist. %3C/em%3E%22We%20have%20shown%20that%20this%20works%20across%20a%20metropolitan%20fibre%20network,%20over%206.2%20kilometres,%20as%20the%20crow%20flies.%22%3C/p%3E%20%3Cp%3EThe%20Chinese%20researchers%20were%20able%20to%20extend%20their%20teleportation%20further,%20over%20a%2012.5%20km%20area,%20but%20they%20had%20a%20slightly%20different%20set%20up.%20It%20was%20Charlie%20in%20the%20middle%20who%20created%20the%20entangled%20particles%20and%20sent%20one%20to%20Bob,%20instead%20of%20the%20other%20way%20around.%3C/p%3E%20%3Cp%3EThis%20could%20work%20best%20for%20a%20quantum%20network%20where%20a%20central%20quantum%20computer%20%28Charlie%29%20communicates%20with%20lots%20of%20Alice%27s%20and%20Bob%27s%20around%20a%20city.%20But%20the%20Calgary%20model%20could%20spread%20even%20greater%20distances,%20because%20Bob%20could%20work%20like%20a%20quantum%20repeater,%20sending%20the%20information%20further%20and%20further%20down%20the%20line.%3C/p%3E%20%3Cp%3EThe%20downside%20to%20both%20experiments%20was%20that%20they%20couldn%27t%20send%20very%20much%20information.%20The%20Calgary%20experiment%20was%20the%20fastest,%20managing%20to%20send%2017%20photons%20a%20minute. %3C/p%3E%20%3Cp%3EAnd%20while%20many%20people%20assume%20that%20quantum%20teleportation%20would%20result%20in%20instantaneous%20communication,%20in%20reality,%20decrypting%20the%20quantum%20state%20of%20the%20entangled%20particle%20requires%20a%20key,%20that%20needs%20to%20be%20sent%20via%20regular%20slow%20communication%20-%20so%20quantum%20teleportation%20wouldn%27t%20actually%20be%20any%20faster%20than%20the%20internet%20we%20already%20have,%20just%20more%20secure.%3C/p%3E%20%3Cp%3EBut%20the%20fact%20that%20both%20teams%20were%20able%20to%20use%20existing%20telecommunications%20infrastructure%20to%20achieve%20such%20long-distance%20quantum%20teleportation%20at%20all%20is%20a%20huge%20deal%20-%20and%20something%20that%20hasn%27t%20been%20done%20outside%20of%20the%20lab%20before.%3C/p%3E%20%3Cp%3EIt%27s%20going%20to%20take%20a%20lot%20more%20tweaking%20and%20investigation%20before%20it%27s%20something%20that%20we%20can%20use%20in%20our%20daily%20lives,%20but%20we%27re%20definitely%20getting%20closer.%3C/p%3E). "We have shown that this works across a metropolitan fibre network, over 6.2 kilometres, as the crow flies."
The Chinese researchers were able to extend their teleportation further, over a 12.5 km area, but they had a slightly different set-up. It was Charlie in the middle who created the entangled particles and sent one to Bob, instead of the other way around.
This resulted in more accurate communication (http://blogs.discovermagazine.com/d-brief/2016/09/19/quantum-teleportation-enters-real-world/#.V-CwmpN95ok), and could work best for a quantum network where a central quantum computer (Charlie) communicates with lots of Alices and Bobs around a city. But the Calgary model could spread even greater distances, because Bob could work like a quantum repeater, sending the information further and further down the line.
The downside to both experiments was that they couldn't send very much information. The Calgary experiment was the fastest, managing to send just 17 photons a minute (http://blogs.discovermagazine.com/d-brief/2016/09/19/quantum-teleportation-enters-real-world/#.V-CwmpN95ok).
And while many people assume that quantum teleportation would result in faster communication, in reality, decrypting the quantum state of the entangled particle requires a key, which needs to be sent via regular, slow communication - so quantum teleportation wouldn't actually be any faster than the internet we already have, just more secure.
But the fact that both teams were able to use existing telecommunications infrastructure to achieve such long-distance teleportation at all is a huge deal - and something that hasn't been done outside of the lab (http://www.sciencealert.com/a-new-quantum-teleportation-distance-record-has-been-set) before.
It's going to take a lot more tweaking and investigation before it's something that we can use in our daily lives, but we're definitely getting closer.
 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 02-12-2016, 08:53:04
 Theory challenging Einstein's view on speed of light could soon be tested  (https://www.theguardian.com/science/2016/nov/28/theory-challenging-einsteins-view-on-speed-of-light-could-soon-be-tested)

Quote
The newborn universe may have glowed with light beams moving much faster than they do today, according to a theory that overturns Einstein’s century-old claim that the speed of light is a constant.

João Magueijo, of Imperial College London, and Niayesh Afshordi, of the University of Waterloo in Canada, propose that light tore along at infinite speed at the birth of the universe when the temperature of the cosmos was a staggering ten thousand trillion trillion celsius.

It is a theory Magueijo has being developing since the late 1990s, but in a paper published on Monday he and Afshordi describe for the first time how scientists can finally test the controversial idea. If right, the theory would leave a signature on the ancient radiation left over from the big bang, the so-called cosmic microwave background that cosmologists have observed with satellites.

“We can say what the fluctuations in the early universe would have looked like, and these are the fluctuations that grow to form planets, stars and galaxies,” Afshordi told the Guardian.

The speed of light in a vacuum is considered to be one of the fundamental constants of nature. Thanks to Einstein’s theory of general relativity, it was stamped in the annals of physics more than a century ago at about 1bn km/h. But while general relativity is one of the cornerstones of modern physics, scientists know that the rules of today did not hold at the birth of the universe.

Magueijo and Afshordi came up with their theory to explain why the cosmos looks much the same over vast distances. To be so uniform, light rays must have reached every corner of the cosmos, otherwise some regions would be cooler and more dense than others. But even moving at 1bn km/h, light was not travelling fast enough to spread so far and even out the universe’s temperature differences.

To overcome the conundrum, cosmologists including Stephen Hawking have proposed a theory called inflation, in which the fledgling universe underwent the briefest spell of the most tremendous expansion. According to inflation, the temperature of the cosmos evened out before it exploded to an enormous size. But there is no solid proof that inflation is right, and if so, what sparked such a massive period of expansion, and what brought it to an end.

Magueijo and Afshordi’s theory does away with inflation and replaces it with a variable speed of light. According to their calculations, the heat of universe in its first moments was so intense that light and other particles moved at infinite speed. Under these conditions, light reached the most distant pockets of the universe and made it look as uniform as we see it today. “In our theory, if you go back to the early universe, there’s a temperature when everything becomes faster. The speed of light goes to infinity and propagates much faster than gravity,” Afshordi said. “It’s a phase transition in the same way that water turns into steam.”

Scientists could soon find out whether light really did outpace gravity in the early universe. The theory predicts a clear pattern in the density variations of the early universe, a feature measured by what is called the “spectral index”. Writing in the journal Physical Review (https://journals.aps.org/prd/abstract/10.1103/PhysRevD.94.101301), the scientists predict a very precise spectral index of 0.96478, which is close to the latest, though somewhat rough, measurement of 0.968.
Science can never prove the theory right. But Afshordi said that if measurements over the next five years shifted the spectral index away from their prediction, it would rule out their own theory. “If we are right then inflation is wrong. But the problem with inflation is that you can always fine tune it to fit anything you want,” he said.
David Marsh, of the Centre for Theoretical Cosmology at Cambridge University, is not giving up on inflation yet. “The predictions of inflation developed by Stephen Hawking and others more than 30 years ago have been tested by cosmological observations and faced those tests remarkably well. Many scientists regard inflation as a simple and elegant explanation of the origin of galaxies in the universe,” he said.
And while other theories might also look promising, Marsh said there were elements of Afshordi and Magueijo’s that were not well understood. “It remains to be seen how robust the predictions are when all the theoretical issues have been addressed,” he said.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 26-12-2016, 08:44:19
Quantum Leap: Researchers Send Information Using a Single Particle of Light (http://motherboard.vice.com/en_au/read/quantum-leap-researchers-send-information-using-a-single-particle-of-light)



Quote
According to research published Thursday in Science (http://science.sciencemag.org/content/early/2016/12/21/science.aal2469?rss=1), physicists at Princeton University have designed a device that allows a single electron to pass its quantum information to a photon in what could be a big breakthrough for silicon-based quantum computers.
"We now have the ability to actually transmit the quantum state to a photon," said (https://www.princeton.edu/main/news/archive/S48/24/15E12/?section=topstories) Xiao Mi, a graduate student in Princeton's Department of Physics. "This has never been done before in a semiconductor device because the quantum state was lost before it could transfer its information."
The device designed by the Princeton researchers is the result of five years of research and works by trapping an electron and a photon within a device built by HRL laboratories, which is owned by Boeing and General Motors. It is a semi-conductor chip made from layers of silicon and silicon-germanium, materials that are inexpensive and already widely deployed in consumer electronics.
Across the top of this wafer of silicon layers were laid a number of nanowires, each smaller than the width of a human hair, which were used to deliver energy to the chip. This energy allowed the researchers to trap an electron in between the silicon layers of the chip in microstructures known as quantum dots (http://science.sciencemag.org/content/309/5744/2173).
The electrons function as the smallest units of data used in computing which are known as bits. In a regular computer, a bit can have one of two values: either a 0 or a 1. But in a quantum computer, the smallest units of data are known as qubits, which can have a value of both 0 and 1 simultaneously. The ability to manipulate data as qubits in a quantum computer will allow for faster computing (https://uwaterloo.ca/institute-for-quantum-computing/quantum-computing-101) because the machine can calculate many problems simultaneously instead of one at a time.
“In our device, the state of the qubit is encoded in the position of the electron,” Jason Petta, a professor of physics at Princeton, told Motherboard. “The electron is trapped in a double well potential where the electron can occupy the left well, the right well, or be in a superposition state: both left and right at the same time. The information is therefore stored in the position of a single electron.”
The thing about quantum information, however, is that it is extremely fragile. Indeed, just measuring a quantum state (http://phys.org/news/2009-01-quantum.html) can corrupt it, so figuring out a way to pass information from electron to electron without destroying it in the process was no small task.
The researchers settled on photons as the medium of exchange between electrons since they are less sensitive to disruption from their environment and could potentially be used to carry quantum information between quantum chips, rather than within the circuits on a single quantum chip. The ability to scale up this device would mean that photons could be used to pass quantum information from electron to electron in order to form the circuits for a quantum computer.
"Just like in human interactions, to have good communication a number of things need to work out —it helps to speak the same language and so forth," said (https://www.princeton.edu/main/news/archive/S48/24/15E12/?section=topstories) Jason Petta, a professor of physics at Princeton. "We are able to bring the energy of the electronic state into resonance with the light particle, so that the two can talk to each other."
Following their successful experiment, the Princeton researchers hope to fine tune their device so that it is also able to electrically manipulate the spin of the trapped electrons giving them even greater control over the exchange of information between qubits.
“Our next step is to couple spin to light,” said Petta. “The spin of the electron, or its magnetic moment, has some advantages, as the spin state of an electron in silicon can remain coherent for a much longer time. So in principle, one can perform many gate operations electrically before the spin superposition state collapses.”
   
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 20-03-2017, 09:02:47
 Physicists Find That as Clocks Get More Precise, Time Gets More Fuzzy  (http://www.sciencealert.com/physicists-find-as-clocks-get-more-precise-time-gets-more-fuzzy)



Quote
  Time is weird – in spite of what we think, the Universe doesn't have a master clock to run by (http://www.sciencealert.com/here-s-how-einstein-s-general-theory-of-relativity-killed-off-common-sense-physics), making it possible for us to experience time differently depending on how we're moving or how much gravity is pulling on us.
Now physicists have combined two grand theories of physics to conclude not only is time not universally consistent, any clock we use to measure it will blur the flow of time in its surrounding space.
Don't worry, that doesn't mean your wall clock is going to make you age quicker. We're talking about time keepers in highly precise experiments here, such as atomic clocks
A team of physicists from the University of Vienna (https://www.univie.ac.at/en/) and the Austrian Academy of Sciences (http://www.oeaw.ac.at/en/austrian-academy-of-sciences/) have applied quantum mechanics and general relativity to argue that increasing the precision of measurements on clocks in the same space also increases their warping of time.
Let's take a step back for a moment and consider in simple terms what physicists already know.
Quantum mechanics (https://en.wikipedia.org/wiki/Quantum_mechanics) is incredibly useful in describing the Universe on a very tiny scale, such as sub-atomic particles and forces over short distances.
As accurate and incredibly useful as the mathematics supporting quantum mechanics might be, it makes predictions which seem counter-intuitive to our everyday experiences.
One such prediction is called Heisenberg's uncertainty principle (https://en.wikipedia.org/wiki/Uncertainty_principle), which says as you know one thing with increasing precision, measurement of a complementary variable becomes less precise.
For example, the more you pinpoint the position of an object in time and space, the less certain you can be about its momentum.
This isn't a question of being clever enough or having better equipment – the Universe fundamentally works this way; electrons keep from crashing into protons (https://www.theguardian.com/science/2013/nov/10/what-is-heisenbergs-uncertainty-principle) thanks to a balance of 'uncertainty' of position and momentum.
Another way to think of it is this: objects with ultra-precise positions require us to consider increasingly ridiculous amounts of energy.
Applied to a hypothetical timepiece, splitting fractions of a second on our clock makes us less certain about the clock's energy.
This is where general relativity (https://en.wikipedia.org/wiki/General_relativity) comes in – another highly trusted theory in physics, only this time it is most useful in explaining how massive objects affect one another at a distance.
Thanks to Einstein's work, we understand there is an equivalence between mass and energy (https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence), made famous in the equation (for objects at rest) as Energy = mass x speed of light squared (or E=mc^2).
We also know time and space are connected, and that this space-time can be affected as if it was more than just an empty box; mass – and therefore energy – can 'bend' it.
This is why we see cool things like gravitational lensing (http://www.sciencealert.com/galaxy-sized-lenses-confirm-it-the-universe-is-expanding-faster-than-ever), where massive objects like stars and black holes dimple space so much, light can both travel straight and yet bend around them.
It also means mass can affect time through a phenomenon called gravitational time dilation (https://en.wikipedia.org/wiki/Gravitational_time_dilation), where time looks like it is running slower the closer it gets to a gravitational source.
Unfortunately, while the theories are both supported by experiments, they usually don't play well together, forcing physicists to consider a new theory that will allow them both to be correct at the same time.
Meanwhile, it's important that we continue to understand how both theories describe the same phenomena, such as time. Which is what this new paper does.
In this case, the physicists hypothesised the act of measuring time in greater detail requires the possibility of increasing amounts of energy, in turn making measurements in the immediate neighbourhood of any time-keeping devices less precise.
"Our findings suggest that we need to re-examine our ideas about the nature of time when both quantum mechanics and general relativity are taken into account", says researcher Esteban Castro (https://phys.org/news/2017-03-blurred-quantum-world.html).
So how does this affect us on a day-to-day level? Like a lot of theoretical physics, probably not much at all.
While quantum mechanics technically applies to 'big' things, don't worry, setting your stop-watch to read fractions of a second isn't going to open a worm-hole on your wrist – these findings would only become significant for clocks in highly precise experiments far more advanced than those currently being developed.
But getting a better understanding of how these time pieces work, in theory at least, will ultimately help us better understand the Universe around us. And one day perhaps grasp the nature of time itself.
This research was published in the Proceedings of the National Academy of Sciences (http://www.pnas.org/content/early/2017/03/06/1616427114).
 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Father Jape on 02-04-2017, 13:10:44
http://www.nature.com/news/it-s-not-just-you-science-papers-are-getting-harder-to-read-1.21751?WT.ec_id=NEWSDAILY-20170331
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: ЖивОзбиљан on 02-04-2017, 13:13:58
Zato Flat Earth teoretičari sve jasno objasne!
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Ugly MF on 02-04-2017, 14:52:08
 :|
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 20-06-2017, 07:55:02
Physicists Discover a Possible Break in the Standard Model of Physics (https://futurism.com/physicists-discover-possible-break-standard-model-physics/)



Quote
Physicists from UC Santa Barbara and elsewhere discovered a phenomenon that doesn't follow one of the basic assumptions held by the Standard Model of Physics, after the teams reviewed three separate experiments.




Breaking the Lepton Universality In order to make sense of the physical world, scientists have worked hard to discover theories and principles that govern the physics of matter. This is what’s called the Standard Model of Physics, which includes all the laws and principles concerning matter in all its forms and sizes. Bascially, the Standard Model applies to even particle physics. Or so it should.
Scientists from the University of California at Santa Barbara (USCB) and colleagues from various other institutions have recently discovered that there might be a break in the application of the Standard Model, particularly with a fundamental principle called the lepton universality (https://en.wikipedia.org/wiki/Lepton). Their discovery comes from reviewing the data from three separate experiments conducted in the United States, Switzerland, and Japan.


https://youtu.be/V0KjXsGRvoA




But before we jump into the details of the study (https://www.nature.com/nature/journal/v546/n7657/full/nature22346.html) published in the journal  (https://www.nature.com/nature/journal/v546/n7657/full/nature21721.html)Nature (https://www.nature.com/nature/journal/v546/n7657/full/nature21721.html), a little backgrounder is in order. The lepton universality is an assumption concerning elementary particles called leptons, which don’t undergo strong interactions. Supposedly, lepton universality asserts that the interactions of these particles are the same, regardless of differences in masses and decay rates. The three experiments reviewed in the studies are charged leptons, which are electrons, muons, and the heavier taus.
 Challenging the Norms of Physics All three experiments revealed that taus actually decay faster than the standard model predicts. The surprising thing was the data which came from the LHCb experiment at CERN in Switzerland, the BaBaR detector of the SLAC National Accelerator Laboratory in California, and the Belle experiment in Japan challenged lepton universality at four standard deviations. This means that there’s a 99.95 percent certainty that this data is accurate, according to the USCB team.
“The tau lepton is key, because the electron and the muon have been well measured. Taus are much harder because they decay very quickly,” USCB’s Franco Sevilla said in a press release (http://www.news.ucsb.edu/2017/018050/not-so-elementary). “Now that physicists are able to better study taus, we’re seeing that perhaps lepton universality is not satisfied as the Standard Model claims.”


Initial reading into these results would seem to indicate that there is indeed a deviation from the Standard Model of particle physics (https://futurism.com/standard-model-an-overview-of-particle-physics/). This could mean that an entirely different model of physics is needed (https://futurism.com/new-model-on-fundamental-particles-may-solve-age-old-physics-inconsistencies/) to explain the peculiar behavior of the tau particle. In other words, new physics is required. That’s not a simple thing, as these principles often correlate with one another. A change in one could affect the others.
Sevilla admitted that they aren’t entirely sure yet how this would play out. “We’re not sure what confirmation of these results will mean in the long term,” he explained. “First, we need to make sure that they’re true, and then we’ll need ancillary experiments to determine the meaning.”




https://www.nature.com/nature/journal/v546/n7657/full/nature22346.html
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 19-07-2017, 05:24:43
Quantum mechanical particles travel backwards, study confirms (https://www.upi.com/Science_News/2017/07/18/Quantum-mechanical-particles-travel-backwards-study-confirms/5011500383202/)
 
Quote
July 18 (UPI) -- A team of particle physicists and mathematicians have confirmed all quantum mechanical particles move backwards -- in the opposite direction of the force acting upon them. The phenomenon is called "backflow."
Until now, scientists had only observed the counterintuitive movement among "free" quantum particles -- particles free from any active forces. In the newest experiments, researchers showed quantum particles move in reverse even when pushed by an active force.
Scientists used advanced mathematical analysis to confirm the presence of backflow. Though the phenomenon is ubiquitous, it is a very weak force and hard to measure. Small or not, understanding the effect is essential to designing technologies that take advantage of quantum mechanics.
"We have shown that backflow can always occur, even if a force is acting on the quantum particle while it travels," Henning Bostelmann, a mathematician at the University of York, said in a news release (https://www.york.ac.uk/news-and-events/news/2017/research/quantum-particle-backwards/). "The backflow effect is the result of wave-particle duality and the probabilistic nature of quantum mechanics, and it is already well understood in an idealised case of force-free motion."
Researchers published their findings this week in the journal Physical Review A (https://journals.aps.org/pra/abstract/10.1103/PhysRevA.96.012112).
"As 'free' quantum particles are an idealized, perhaps unrealistic situation, we have shown that backflow still occurs when external forces are present. This means that external forces don't destroy the backflow effect, which is an exciting new discovery," said Daniela Cadamuro, a researcher at the Technical University of Munich. "These new findings allow us to find out the optimal configuration of a quantum particle that exhibits the maximal amount of backflow, which is important for future experimental verification."
 
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 23-07-2017, 05:40:39
Surprise! The proton is lighter than we thought (http://www.sciencemag.org/news/2017/07/surprise-proton-lighter-we-thought)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 04-11-2017, 07:35:08
Subatomic Event More Powerful Than A Hydrogen Bomb Discovered—Scaring Scientists So Much They Almost Hid The Results (http://www.newsweek.com/subatomic-event-more-powerful-hydrogen-bomb-discovered-scaring-scientists-so-700779)
 
Evo i sam rad za naprednije čitaoce:
 
https://www.nature.com/articles/nature24289 (https://www.nature.com/articles/nature24289)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 29-04-2018, 05:22:59
Einstein's 'Spooky Action' Has Just Been Demonstrated on a Massive Scale For The First Time  (https://www.sciencealert.com/einstein-spooky-action-demonstrated-on-massive-scale-for-first-time)

Evo i samog rada za ljude alergične na pojednostavljen jezik:
 
https://www.nature.com/articles/s41586-018-0038-x (https://www.nature.com/articles/s41586-018-0038-x)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 17-09-2018, 07:55:31
Quantum mechanics defies causal order, experiment confirms (https://physicsworld.com/a/quantum-mechanics-defies-causal-order-experiment-confirms/)
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: mac on 21-10-2018, 00:34:13
The Universe Is Always Looking

https://www.theatlantic.com/science/archive/2018/10/beyond-weird-decoherence-quantum-weirdness-schrodingers-cat/573448/

Eto ti, Džozefino, pa čitaj..
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 21-10-2018, 07:02:57
Zaista elegantan i razumljiv tekst čak i za mene koji sam bez ikakve škole.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 06-06-2019, 08:03:10
Da vidimo sad ovo:

Physicists can predict the jumps of Schrodinger's cat (and finally save it) (https://phys.org/news/2019-06-physicists-schrodinger-cat.html)

Evo i studije:

https://www.nature.com/articles/s41586-019-1287-z

Quote
In quantum physics, measurements can fundamentally yield discrete and random results. Emblematic of this feature is Bohr’s 1913 proposal of quantum jumps between two discrete energy levels of an atom1 (https://www.nature.com/articles/s41586-019-1287-z#ref-CR1). Experimentally, quantum jumps were first observed in an atomic ion driven by a weak deterministic force while under strong continuous energy measurement2 (https://www.nature.com/articles/s41586-019-1287-z#ref-CR2),3 (https://www.nature.com/articles/s41586-019-1287-z#ref-CR3),4 (https://www.nature.com/articles/s41586-019-1287-z#ref-CR4). The times at which the discontinuous jump transitions occur are reputed to be fundamentally unpredictable. Despite the non-deterministic character of quantum physics, is it possible to know if a quantum jump is about to occur? Here we answer this question affirmatively: we experimentally demonstrate that the jump from the ground state to an excited state of a superconducting artificial three-level atom can be tracked as it follows a predictable ‘flight’, by monitoring the population of an auxiliary energy level coupled to the ground state. The experimental results demonstrate that the evolution of each completed jump is continuous, coherent and deterministic. We exploit these features, using real-time monitoring and feedback, to catch and reverse quantum jumps mid-flight—thus deterministically preventing their completion. Our findings, which agree with theoretical predictions essentially without adjustable parameters, support the modern quantum trajectory theory5 (https://www.nature.com/articles/s41586-019-1287-z#ref-CR5),6 (https://www.nature.com/articles/s41586-019-1287-z#ref-CR6),7 (https://www.nature.com/articles/s41586-019-1287-z#ref-CR7),8 (https://www.nature.com/articles/s41586-019-1287-z#ref-CR8),9 (https://www.nature.com/articles/s41586-019-1287-z#ref-CR9) and should provide new ground for the exploration of real-time intervention techniques in the control of quantum systems, such as the early detection of error syndromes in quantum error correction.
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 05-07-2019, 07:59:01
Ovaj tekst je vrlo zanimljiv osim što uopšte ne objašnjava šta bi bio "mirror universe" ili barem "mirror particle".


Scientists are searching for a mirror universe. It could be sitting right in front of you. (https://www.nbcnews.com/mach/science/scientists-are-searching-mirror-universe-it-could-be-sitting-right-ncna1023206)

Tako da, evo vikipedije da se pripomogne:

https://en.wikipedia.org/wiki/Mirror_matter
Title: Re: Uobičajena interpretacija Hajzenbergovog principa neizvesnosti pogrešna?
Post by: Meho Krljic on 13-07-2019, 05:36:26
Scientists unveil image of quantum entanglement for the first time ever (https://www.engadget.com/2019/07/12/bell-quantum-entanglement-image-university-of-glasgow/?yptr=yahoo) 
 
Quote

 The photo depicts two photons interacting and sharing physical states for a brief instant -- an event that occurs regardless of the actual distance between the particles.
 
(...)
 
A camera capable of detecting photons was then set to snap a photo when it identified one photon entangled with another.
 

 
Da, ni ja nisam siguran kako "fotografišete" fotone, but here we are...
 
 
(https://i.imgur.com/xQlBESY.jpg)