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Pitanja u vezi sa astronomijom/astrofizikom

Started by Nightflier, 28-08-2010, 16:16:14

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lilit

#250
13-04-2019, 22:12:12
agli ima moju podršku!  xrofl
That's how it is with people. Nobody cares how it works as long as it works.

Meho Krljic

#251
28-04-2019, 07:41:03
New Hubble measurements confirm universe is expanding faster than expected

Quote
New measurements from NASA's Hubble Space Telescope confirm that the Universe is expanding about 9% faster than expected based on its trajectory seen shortly after the big bang, astronomers say. 

Meho Krljic

#252
30-06-2019, 07:15:39
Researchers decipher the history of supermassive black holes in the early universe


Konkretnije, ovaj rad pokazuje mehanizam po kome supermasivne crne rupe(možda) nisu nastale od zvezda jer su se formirale tako brzo da su "odmah" kolabirale u, jelte singularitet.

Meho Krljic

#257
12-08-2019, 09:08:31
Pokušavam da dozovem Aglija ovakvim vestima:


Dark matter may be older than the Big Bang

Quote"The study revealed a new connection between particle physics and astronomy. If dark matter consists of new particles that were born before the Big Bang, they affect the way galaxies are distributed in the sky in a unique way. This connection may be used to reveal their identity and make conclusions about the times before the Big Bang too," says Tommi Tenkanen, a postdoctoral fellow in Physics and Astronomy at the Johns Hopkins University and the study's author.

Meho Krljic

#258
07-09-2019, 06:08:59
Brzina ekspanzije svemira nikako da poprimi neku logičnu vrednost.


One Number Shows Something Is Fundamentally Wrong with Our Conception of the Universe

Meho Krljic

#259
18-09-2019, 08:40:48
Astronomers Detect the Most Massive Neutron Star Yet

QuoteThe newly measured neutron star, called J0740+6620, lies about 4,600 light-years from Earth. It packs 2.14 times the mass of the sun into a sphere only about 15 miles (25 km) in diameter. That approaches the theoretical limits of how massive and compact a single object can become without crushing itself down under the force of its own gravitational pull into a black hole.

Meho Krljic

#261
02-10-2019, 06:45:34
Ovo je sve za sada prilična spekulacija, rad na kome se članak zasniva nije još ni publikovan, ali je zanimljivo:

If Planet 9 Is Actually a Black Hole, It Completely Changes How We Understand Our Universe

Meho Krljic

#262
04-10-2019, 05:52:01
    Scientists start mapping the hidden web that scaffolds the universe


QuoteAfter counting all the normal, luminous matter in the obvious places of the universe – galaxies, clusters of galaxies and the intergalactic medium – about half of it is still missing. So not only is 85% of the matter in the universe made up of an unknown, invisible substance dubbed "dark matter", we can't even find all the small amount of normal matter that should be there.
This is known as the "missing baryons" problem. Baryons are particles that emit or absorb light, like protons, neutrons or electrons, which make up the matter we see around us. The baryons unaccounted for are thought to be hidden in filamentary structures permeating the entire universe, also known as "the cosmic web".
         

Evo studije na kojoj je članak baziran  ako neko želi da se napoji direkt sa izvora (i ako plaća pretplatu..):

Gas filaments of the cosmic web located around active galaxies in a protocluster   

Izitpajn

#263
07-10-2019, 12:55:58
Quote from: Meho Krljic on 04-10-2019, 05:52:01[/b]Evo studije na kojoj je članak baziran  ako neko želi da se napoji direkt sa izvora (i ako plaća pretplatu..):

Gas filaments of the cosmic web located around active galaxies in a protocluster   

ArXiv je majka svih arhiva ;)

https://arxiv.org/abs/1910.01324

Meho Krljic

#264
19-10-2019, 06:56:59
Quote from: Meho Krljic on 18-08-2018, 06:43:25
Evo, kome se čita studija koja tvrdi da je verovatnoća da u univerzumu ima još inteligentnog života zapravo mnogo manja nego što smo do sada mislili:


Dissolving the Fermi Paradox


Quote
Abstract

The Fermi paradox is the conflict between an expectation of a high ex ante probability of intelligent life elsewhere in the universe and the
apparently lifeless universe we in fact observe. The expectation that the universe should be teeming with intelligent life is linked to models like the Drake equation, which suggest that even if the probability of intelligent life developing at a given site is small, the sheer multitude
of possible sites should nonetheless yield a large number of potentially observable civilizations. We show that this conflict arises from the use of Drake-like equations, which implicitly assume certainty regarding highly uncertain parameters. We examine these parameters, incorporating models of chemical and genetic transitions on paths to the origin of life, and show that extant scientific knowledge orresponds to uncertainties that span multiple orders of magnitude. This makes a stark difference. When the model is recat to represent realistic distributions of uncertainty, we find a substantial ex ante probability of there being no other intelligent life in ou observable universe, and thus that there should be little surprise whenwe fail to detect any signs of it. This result dissolves the Fermi paradox,
and in doing so removes any need to invoke speculative mechanisms by which civilizations would inevitably fail to have observable effects upon the universe.


Slično:

    Evolution tells us we might be the only intelligent life in the universe    

Accuphase

#270
09-11-2019, 12:18:52
Voyager 1 je dosta brži od sonde blizanca Voyager 2 stoga je i ranije prošao kroz heliopauzu i tako ušao u međuzvezdani prostor.

https://voyager.jpl.nasa.gov/mission/status/

https://www.skyandtelescope.com/astronomy-news/interstellar-space-the-view-voyager-2/

Accuphase

#271
10-11-2019, 21:52:33
Treba imati na umu da sonde Voyager ne idu jedna za drugom, zapravo sada se kreću jedna južno a drugo severno od ravni ekliptike odnosno ravni revolucije Zemlje oko Sunca.
Moguće je uzimajući u obzir nagib ekliptike u odnosu na ravan Galaksije i u odnosu na pravac kretanja Sunca oko centra same Galaksije do to ima uticaja na očitavanja instrumenata na sondama.
Drugim rečima heliosfera najverovatnije ni nema sferičan oblik već drugačije oblikovan samim kretanjem Sunca.

Accuphase

#273
11-11-2019, 16:22:55
Poštovani Meho nije li poželjno ponekad napisati i poneki komentar sem postavljanja linkova na po pravilu strane sajtove?
Svaka vama čast što vas toliko toga očito interesuje ali ovo bi zaista trebalo da ispoštujete.

Boban

#276
11-11-2019, 17:00:46
kad sam ja bio mlad, verovalo se da je Sunčev sistem prečnika 300 milijardi kilometara, a sada vidim da se pominje 10x manja vrednost. Realno, Sunčev sistem je doklegod gravitacija Sunca nešto drži i privlači, a ne samo doseg magnetnog polja.
Put ćemo naći ili ćemo ga napraviti.

Accuphase

#277
11-11-2019, 17:52:25
Inače ovom metodom tranzita ili okultacije se otkrivaju vansolarne planete oko drugih zvezda.
Golom oku nevidljivo ali osetljivim instrumentima merljivo smanjenje sjaja zvezde izazvano praktično "pomračenjem" daleke planete oko matične zvezde je dokaz da ista postoji.

Meho Krljic

#278
18-11-2019, 08:49:09
There's Growing Evidence That the Universe Is Connected by Giant Structures

QuoteScientists are finding that galaxies can move with each other across huge distances, and against the predictions of basic cosmological models. The reason why could change everything we think we know about the universe.

Meho Krljic

#281
06-12-2019, 06:49:18
An experiment that solved a 100-year-old mystery posed by Einstein just got up to 50% more powerful by squeezing light


Quote
One of the most remarkable experiments in history — a trio of giant machines that listen for ripples in spacetime called gravitational waves — just got more powerful and precise.

Meho Krljic

#282
07-12-2019, 06:36:54
Will We Ever Find Dark Matter in the Universe? 

Quote
One newly popular idea is that the dark matter might not be alone, but instead could be one of several kinds of particles that constitute what is known as a "hidden sector." The particles that make up such a hidden sector could interact among each other, but almost never with any of the known forms of matter, explaining why they have been so difficult to detect in underground experiments or to produce at the Large Hadron Collider. The particles that make up a hidden sector could have evolved and interacted in the early universe in any number of potentially complex ways, even experiencing forces that we have never witnessed. Particle physicists have proposed many theories in which the interactions between multiple kinds of hidden matter can lead to the viable production of dark matter in the early universe. In fact, it's been quite easy for particle physicists to come up with viable hidden sector theories that behave in this way.

Meho Krljic

#283
10-12-2019, 09:01:36
This huge galaxy has the biggest black hole ever measured

QuoteThe monster black hole in galaxy cluster Abell 85 is roughly the size of our solar system, but packs the mass of 40 billion suns.

:shock: :shock: :shock: :shock:
Da prevedemo: to je masa približno ekvivalentna dvema trećinama čitavog Mlečnog puta. MASIVNO.

Meho Krljic

#285
16-12-2019, 07:26:45
Astronomers find 19 more galaxies missing their dark matter 

Tamna materija je stvarno glavobolna, ne valja kad je ima, ne valja kad je nema...

Meho Krljic

#288
31-01-2020, 06:08:51
What if the Shape of the Universe Is Curved? 

Quote

Now our new paper, published in Nature Astronomy, has come to a conclusion that may unleash a crisis in cosmology – if confirmed. We show that the shape of the universe may actually be curved rather than flat, as previously thought – with a probability larger than 99%. In a curved universe, no matter which direction you travel in, you will end up at the starting point – just like on a sphere. Though the universe has four dimensions, including time.

    The result was based on recent measurements of the Cosmic Microwave Background, the light left over from the Big Bang, collected by the Planck Satellite. According to Albert Einstein's theory of general relativity, mass warps space and time around it. As a result, light rays take an apparent turn around a massive object rather than travelling in a straight line – an effect known as gravitational lensing.

Meho Krljic

#289
01-02-2020, 07:33:48
This Is Wild: Astrophysicists Can See Stars Twisting Space and Time 

Quote
The system, named PSR J1141-6545, is made of two stars: "One is a white dwarf, the size of the Earth but 300,000 times its density; the other is a neutron star which, while only 20 kilometres in diameter, is about 100 billion times the density of the Earth," the press release says.

(...)

All of this means that for the first time, astrophysicists have recorded evidence of the predicted phenomenon of frame dragging. If spacetime is colloquially indeed a "fabric," it's an elastic one, where spinning objects receive that stored energy back from the fabric of spacetime itself. And objects within spacetime can pass energy back and forth the same way, making it both convenient and attractive, literally, to join into energy-saving pairs like this binary system.

Meho Krljic

#290
06-02-2020, 07:11:07
   Scientists puzzled by ancient monster galaxy which was suddenly 'snuffed out' 

"Snuffed out" u smislu da više ne proizvodi nove zvezde, i mada tekst treba čitati uz dosta rezervi, zanimljiv je.

Meho Krljic

#291
20-02-2020, 06:22:56
Two Black Holes Are Merging at the Center of a Distant Galaxy 

"Merging" je možda prejaka reč za dva objekta u dve različite galaksije, a koja kruže oko zajeedničkog središta ali ima tu flertovanja.

Meho Krljic

#292
21-02-2020, 06:49:23
 The growing crisis in cosmology

Dalja priča o Hablovoj konstanti.

Meho Krljic

#294
09-03-2020, 08:50:35
Physicists Think We Might Have a New, Exciting Dark Matter Candidate

Nije baš "astrofizika", više fizika osnovnih čestica, ali sve je to povezano.

Meho Krljic

#298
30-03-2020, 08:22:25
Physicists brawl over new dark matter claim 

"Sterilni neutrino" zvuči kao neka ekstremno kastrirana verzija nosoroga.

mac

#299
02-05-2020, 00:36:00
Melodysheep, audio-vizuelni umetnik, koji nam je pre desetak godina podario A Glorious Dawn, a pre godinu dana TIMELAPSE OF THE FUTURE: A Journey to the End of Time, juče je objavio novi kosmogonijski uradak, The Secret History of the Moon.

Vrlo je zanimljivo da sam danas pomislio na Glorious Dawn video, i poželeo da ga ponovo vidim i čujem, i tako otkrio novi video star tek jedan dan. Nije bilo nikakvog podsticaja od strane Jutjuba, ili bilo koga drugog. Zanimljiva koincidencija.
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