ZNAK SAGITE — više od fantastike — edicija, časopis, knjižara...

QuoteIt could be time to bid the Big Bang bye-bye. Cosmologists have speculated that the Universe formed from the debris ejected when a four-dimensional star collapsed into a black hole — a scenario that would help to explain why the cosmos seems to be so uniform in all directions.
[/size]The standard Big Bang model tells us that the Universe exploded out of an infinitely dense point, or singularity. But nobody knows what would have triggered this outburst: the known laws of physics cannot tell us what happened at that moment.[/size]"For all physicists know, dragons could have come flying out of the singularity," says Niayesh Afshordi, an astrophysicist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada.

[/size]It is also difficult to explain how a violent Big Bang would have left behind a Universe that has an almost completely uniform temperature, because there does not seem to have been enough time since the birth of the cosmos for it to have reached temperature equilibrium.
[/size]To most cosmologists, the most plausible explanation for that uniformity is that, soon after the beginning of time, some unknown form of energy made the young Universe inflate at a rate that was faster than the speed of light. That way, a small patch with roughly uniform temperature would have stretched into the vast cosmos we see today. But Afshordi notes that "the Big Bang was so chaotic, it's not clear there would have been even a small homogenous patch for inflation to start working on".[/size]On the braneIn a paper posted last week on the arXiv preprint server[/color]1 (http://www.nature.com/news/did-a-hyper-black-hole-spawn-the-universe-1.13743#b1), Afshordi and his colleagues turn their attention to a proposal[/color]2 (http://www.nature.com/news/did-a-hyper-black-hole-spawn-the-universe-1.13743#b2) made in 2000 by a team including Gia Dvali, a physicist now at the Ludwig Maximilians University in Munich, Germany. In that model, our three-dimensional (3D) Universe is a membrane, or brane, that floats through a 'bulk universe' that has four spatial dimensions.[/color]Ashfordi's team realized that if the bulk universe contained its own four-dimensional (4D) stars, some of them could collapse, forming 4D black holes in the same way that massive stars in our Universe do: they explode as supernovae, violently ejecting their outer layers, while their inner layers collapse into a black hole.In our Universe, a black hole is bounded by a spherical surface called an event horizon. Whereas in ordinary three-dimensional space it takes a two-dimensional object (a surface) to create a boundary inside a black hole, in the bulk universe the event horizon of a 4D black hole would be a 3D object — a shape called a hypersphere. When Afshordi's team modelled the death of a 4D star, they found that the ejected material would form a 3D brane surrounding that 3D event horizon, and slowly expand.The authors postulate that the 3D Universe we live in might be just such a brane — and that we detect the brane's growth as cosmic expansion. "Astronomers measured that expansion and extrapolated back that the Universe must have begun with a Big Bang — but that is just a mirage," says Afshordi.Model discrepancyThe model also naturally explains our Universe's uniformity. Because the 4D bulk universe could have existed for an infinitely long time in the past, there would have been ample opportunity for different parts of the 4D bulk to reach an equilibrium, which our 3D Universe would have inherited.The picture has some problems, however. Earlier this year, the European Space Agency's Planck space observatory released data that mapped the slight temperature fluctuations in the cosmic microwave background — the relic radiation that carries imprints of the Universe's early moments. The observed patterns matched predictions made by the standard Big Bang model and inflation, but the black-hole model deviates from Planck's observations by about 4%. Hoping to resolve the discrepancy, Afshordi says that his is now refining its model.Despite the mismatch, Dvali praises the ingenious way in which the team threw out the Big Bang model. "The singularity is the most fundamental problem in cosmology and they have rewritten history so that we never encountered it," he says. Whereas the Planck results "prove that inflation is correct", they leave open the question of how inflation happened, Dvali adds. The study could help to show how inflation is triggered by the motion of the Universe through a higher-dimensional reality, he says.[/font]

http://www.nature.com/news/did-a-hyper-black-hole-spawn-the-universe-1.13743 (http://www.nature.com/news/did-a-hyper-black-hole-spawn-the-universe-1.13743)

Heh. Ja nisam hteo da otvaram novi topik sa ovom temom pa sam vest zalepio ovde (http://www.znaksagite.com/diskusije/index.php/topic,10662.msg523254.html#msg523254), ali dobro, lepo je i ovako.

izvinjavam se na dabl postu, ja još kao gledao da li ima negde pa nisam našao...

Ma opušteno, verovatno je i bolje da ovakva priča ima svoj topik.

Poneku reč razumem... Universe, black hole...
Mislim da me je vreme pregazilo...  :cry:

A čekaj dok pročitaš ovo:
A Jewel at the Heart of Quantum Physics (https://www.simonsfoundation.org/quanta/20130917-a-jewel-at-the-heart-of-quantum-physics/)
(https://www.znaksagite.com/diskusije/proxy.php?request=http%3A%2F%2Fi40.tinypic.com%2F2jb2woy.jpg&hash=790fcf01f2996970f5eaa0758fc6b21658269cf6)

Quote

Physicists have discovered a jewel-like geometric object that dramatically simplifies calculations of particle interactions and challenges the notion that space and time are fundamental components of reality.

"This is completely new and very much simpler than anything that has been done before," said Andrew Hodges (http://www.maths.ox.ac.uk/contact/details/hodges), a mathematical physicist at Oxford University who has been following the work.

The revelation that particle interactions, the most basic events in nature, may be consequences of geometry significantly advances a decades-long effort to reformulate quantum field theory, the body of laws describing elementary particles and their interactions. Interactions that were previously calculated with mathematical formulas thousands of terms long can now be described by computing the volume of the corresponding jewel-like "amplituhedron," which yields an equivalent one-term expression.

"The degree of efficiency is mind-boggling," said Jacob Bourjaily (http://www-personal.umich.edu/~jbourj/), a theoretical physicist at Harvard University and one of the researchers who developed the new idea. "You can easily do, on paper, computations that were infeasible even with a computer before."

The new geometric version of quantum field theory could also facilitate the search for a theory of quantum gravity that would seamlessly connect the large- and small-scale pictures of the universe. Attempts thus far to incorporate gravity into the laws of physics at the quantum scale have run up against nonsensical infinities and deep paradoxes. The amplituhedron, or a similar geometric object, could help by removing two deeply rooted principles of physics: locality and unitarity.

"Both are hard-wired in the usual way we think about things," said Nima Arkani-Hamed (http://www.sns.ias.edu/~arkani/), a professor of physics at the Institute for Advanced Study in Princeton, N.J., and the lead author of the new work, which he is presenting in talks (http://susy2013.ictp.it/video/05_Friday/2013_08_30_Arkani-Hamed_4-3.html) and in a forthcoming paper. "Both are suspect."

Locality is the notion that particles can interact only from adjoining positions in space and time. And unitarity holds that the probabilities of all possible outcomes of a quantum mechanical interaction must add up to one. The concepts are the central pillars of quantum field theory in its original form, but in certain situations involving gravity, both break down, suggesting neither is a fundamental aspect of nature.

In keeping with this idea, the new geometric approach to particle interactions removes locality and unitarity from its starting assumptions. The amplituhedron is not built out of space-time and probabilities; these properties merely arise as consequences of the jewel's geometry. The usual picture of space and time, and particles moving around in them, is a construct.

"It's a better formulation that makes you think about everything in a completely different way," said David Skinner (http://www.damtp.cam.ac.uk/people/dbs26/), a theoretical physicist at Cambridge University.

The amplituhedron itself does not describe gravity. But Arkani-Hamed and his collaborators think there might be a related geometric object that does. Its properties would make it clear why particles appear to exist, and why they appear to move in three dimensions of space and to change over time.

Because "we know that ultimately, we need to find a theory that doesn't have" unitarity and locality, Bourjaily said, "it's a starting point to ultimately describing a quantum theory of gravity."

Clunky Machinery

The amplituhedron looks like an intricate, multifaceted jewel in higher dimensions. Encoded in its volume are the most basic features of reality that can be calculated, "scattering amplitudes," which represent the likelihood that a certain set of particles will turn into certain other particles upon colliding. These numbers are what particle physicists calculate and test to high precision at particle accelerators like the Large Hadron Collider in Switzerland.
The 60-year-old method for calculating scattering amplitudes — a major innovation at the time — was pioneered by the Nobel Prize-winning physicist Richard Feynman. He sketched line drawings of all the ways a scattering process could occur and then summed the likelihoods of the different drawings. The simplest Feynman diagrams look like trees: The particles involved in a collision come together like roots, and the particles that result shoot out like branches. More complicated diagrams have loops, where colliding particles turn into unobservable "virtual particles" that interact with each other before branching out as real final products. There are diagrams with one loop, two loops, three loops and so on — increasingly baroque iterations of the scattering process that contribute progressively less to its total amplitude. Virtual particles are never observed in nature, but they were considered mathematically necessary for unitarity — the requirement that probabilities sum to one.

"The number of Feynman diagrams is so explosively large that even computations of really simple processes weren't done until the age of computers," Bourjaily said. A seemingly simple event, such as two subatomic particles called gluons colliding to produce four less energetic gluons (which happens billions of times a second during collisions at the Large Hadron Collider), involves 220 diagrams, which collectively contribute thousands of terms to the calculation of the scattering amplitude.

In 1986, it became apparent that Feynman's apparatus was a Rube Goldberg machine.

To prepare for the construction of the Superconducting Super Collider in Texas (a project that was later canceled), theorists wanted to calculate the scattering amplitudes of known particle interactions to establish a background against which interesting or exotic signals would stand out. But even 2-gluon to 4-gluon processes were so complex, a group of physicists had written two years earlier (https://inspirehep.net/record/201469/files/Pub-84-017-T.pdf), "that they may not be evaluated in the foreseeable future."

Stephen Parke and Tommy Taylor, theorists at Fermi National Accelerator Laboratory in Illinois, took that statement as a challenge. Using a few mathematical tricks, they managed to simplify the 2-gluon to 4-gluon amplitude calculation from several billion terms to a 9-page-long formula, which a 1980s supercomputer could handle. Then, based on a pattern they observed in the scattering amplitudes of other gluon interactions, Parke and Taylor guessed a simple one-term expression (http://theory.fnal.gov/people/parke/PAPERS/sjp-1986-1.pdf) for the amplitude. It was, the computer verified, equivalent to the 9-page formula. In other words, the traditional machinery of quantum field theory, involving hundreds of Feynman diagrams worth thousands of mathematical terms, was obfuscating something much simpler. As Bourjaily put it: "Why are you summing up millions of things when the answer is just one function?"

"We knew at the time that we had an important result," Parke said. "We knew it instantly. But what to do with it?"

The Amplituhedron

The message of Parke and Taylor's single-term result took decades to interpret. "That one-term, beautiful little function was like a beacon for the next 30 years," Bourjaily said. It "really started this revolution."
In the mid-2000s, more patterns emerged in the scattering amplitudes of particle interactions, repeatedly hinting at an underlying, coherent mathematical structure behind quantum field theory. Most important was a set of formulas called the BCFW recursion relations, named for Ruth Britto, Freddy Cachazo (http://www.perimeterinstitute.ca/people/freddy-cachazo), Bo Feng (http://physics.zju.edu.cn/english/redir.php?catalog_id=8037&object_id=8078) and Edward Witten (http://www.sns.ias.edu/~witten/). Instead of describing scattering processes in terms of familiar variables like position and time and depicting them in thousands of Feynman diagrams, the BCFW relations are best couched in terms of strange variables called "twistors," (http://www.twistordiagrams.org.uk/) and particle interactions can be captured in a handful of associated twistor diagrams. The relations gained rapid adoption as tools for computing scattering amplitudes relevant to experiments, such as collisions at the Large Hadron Collider. But their simplicity was mysterious.

"The terms in these BCFW relations were coming from a different world, and we wanted to understand what that world was," Arkani-Hamed said. "That's what drew me into the subject five years ago."

With the help of leading mathematicians such as Pierre Deligne (https://www.simonsfoundation.org/science_lives_video/pierre-deligne/), Arkani-Hamed and his collaborators discovered that the recursion relations and associated twistor diagrams corresponded to a well-known geometric object. In fact, as detailed in a paper posted to arXiv.org (http://arxiv.org/abs/1212.5605) in December by Arkani-Hamed, Bourjaily, Cachazo, Alexander Goncharov (http://users.math.yale.edu/public_html/People/ag727.html), Alexander Postnikov (http://math.mit.edu/~apost/about.html) and Jaroslav Trnka (http://www.princeton.edu/~jtrnka/), the twistor diagrams gave instructions for calculating the volume of pieces of this object, called the positive Grassmannian.

Named for Hermann Grassmann, a 19th-century German linguist and mathematician who studied its properties, "the positive Grassmannian is the slightly more grown-up cousin of the inside of a triangle," Arkani-Hamed explained. Just as the inside of a triangle is a region in a two-dimensional space bounded by intersecting lines, the simplest case of the positive Grassmannian is a region in an N-dimensional space bounded by intersecting planes. (N is the number of particles involved in a scattering process.)

It was a geometric representation of real particle data, such as the likelihood that two colliding gluons will turn into four gluons. But something was still missing.

The physicists hoped that the amplitude of a scattering process would emerge purely and inevitably from geometry, but locality and unitarity were dictating which pieces of the positive Grassmannian to add together to get it. They wondered whether the amplitude was "the answer to some particular mathematical question," said Trnka, a post-doctoral researcher at the California Institute of Technology. "And it is," he said.
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Arkani-Hamed and Trnka discovered that the scattering amplitude equals the volume of a brand-new mathematical object — the amplituhedron. The details of a particular scattering process dictate the dimensionality and facets of the corresponding amplituhedron. The pieces of the positive Grassmannian that were being calculated with twistor diagrams and then added together by hand were building blocks that fit together inside this jewel, just as triangles fit together to form a polygon.

Like the twistor diagrams, the Feynman diagrams are another way of computing the volume of the amplituhedron piece by piece, but they are much less efficient. "They are local and unitary in space-time, but they are not necessarily very convenient or well-adapted to the shape of this jewel itself," Skinner said. "Using Feynman diagrams is like taking a Ming vase and smashing it on the floor."

Arkani-Hamed and Trnka have been able to calculate the volume of the amplituhedron directly in some cases, without using twistor diagrams to compute the volumes of its pieces. They have also found a "master amplituhedron" with an infinite number of facets, analogous to a circle in 2-D, which has an infinite number of sides. Its volume represents, in theory, the total amplitude of all physical processes. Lower-dimensional amplituhedra, which correspond to interactions between finite numbers of particles, live on the faces of this master structure.

"They are very powerful calculational techniques, but they are also incredibly suggestive," Skinner said. "They suggest that thinking in terms of space-time was not the right way of going about this."

Quest for Quantum Gravity

The seemingly irreconcilable conflict between gravity and quantum field theory enters crisis mode in black holes. Black holes pack a huge amount of mass into an extremely small space, making gravity a major player at the quantum scale, where it can usually be ignored. Inevitably, either locality or unitarity is the source of the conflict.
"We have indications that both ideas have got to go," Arkani-Hamed said. "They can't be fundamental features of the next description," such as a theory of quantum gravity.
String theory, a framework that treats particles as invisibly small, vibrating strings, is one candidate for a theory of quantum gravity that seems to hold up in black hole situations, but its relationship to reality is unproven — or at least confusing. Recently, a strange duality (https://www.simonsfoundation.org/quanta/20130701-signs-of-a-stranger-deeper-side-to-natures-building-blocks/) has been found between string theory and quantum field theory, indicating that the former (which includes gravity) is mathematically equivalent to the latter (which does not) when the two theories describe the same event as if it is taking place in different numbers of dimensions. No one knows quite what to make of this discovery. But the new amplituhedron research suggests space-time, and therefore dimensions, may be illusory anyway.
"We can't rely on the usual familiar quantum mechanical space-time pictures of describing physics," Arkani-Hamed said. "We have to learn new ways of talking about it. This work is a baby step in that direction."
Even without unitarity and locality, the amplituhedron formulation of quantum field theory does not yet incorporate gravity. But researchers are working on it. They say scattering processes that include gravity particles may be possible to describe with the amplituhedron, or with a similar geometric object. "It might be closely related but slightly different and harder to find," Skinner said.

Physicists must also prove that the new geometric formulation applies to the exact particles that are known to exist in the universe, rather than to the idealized quantum field theory they used to develop it, called maximally supersymmetric Yang-Mills theory. This model, which includes a "superpartner" particle (https://www.simonsfoundation.org/quanta/20121120-as-supersymmetry-fails-tests-physicists-seek-new-ideas/) for every known particle and treats space-time as flat, "just happens to be the simplest test case for these new tools," Bourjaily said. "The way to generalize these new tools to [other] theories is understood."

Beyond making calculations easier or possibly leading the way to quantum gravity, the discovery of the amplituhedron could cause an even more profound shift, Arkani-Hamed said. That is, giving up space and time as fundamental constituents of nature and figuring out how the Big Bang and cosmological evolution of the universe arose out of pure geometry.

"In a sense, we would see that change arises from the structure of the object," he said. "But it's not from the object changing. The object is basically timeless."

While more work is needed, many theoretical physicists are paying close attention to the new ideas.

The work is "very unexpected from several points of view," said Witten, a theoretical physicist at the Institute for Advanced Study. "The field is still developing very fast, and it is difficult to guess what will happen or what the lessons will turn out to be."

I dodatak:

Quote
>Puzzling Thoughts
Locality and unitarity are the central pillars of quantum field theory, but as the following thought experiments show, both break down in certain situations involving gravity. This suggests physics should be formulated without either principle.
Locality says that particles interact at points in space-time. But suppose you want to inspect space-time very closely. Probing smaller and smaller distance scales requires ever higher energies, but at a certain scale, called the Planck length, the picture gets blurry: So much energy must be concentrated into such a small region that the energy collapses the region into a black hole, making it impossible to inspect. "There's no way of measuring space and time separations once they are smaller than the Planck length," said Arkani-Hamed. "So we imagine space-time is a continuous thing, but because it's impossible to talk sharply about that thing, then that suggests it must not be fundamental — it must be emergent."
Unitarity says the quantum mechanical probabilities of all possible outcomes of a particle interaction must sum to one. To prove it, one would have to observe the same interaction over and over and count the frequencies of the different outcomes. Doing this to perfect accuracy would require an infinite number of observations using an infinitely large measuring apparatus, but the latter would again cause gravitational collapse into a black hole. In finite regions of the universe, unitarity can therefore only be approximately known.

Ovo mi sasvim sigurno neće pomoći u lečenju glavobolje...
Mada, ima više poznatijih reči...

Relativno je lakim jezikom objašnjeno mada uvrće mozak svejedno.

Mogao bi da uvećaš font kada kvotuješ, Meho...

Pa, ima link za originalni tekst na početku, ovo kvotovanje je samo za svaki slučaj ako original nestane. A ctrl i plus na numeričkoj tastaturi rešava većinu ovih problema.

ne, ne. bolje je da povećaš font, veruj mi:) hvala na tekstu:)

Ma, naravno da je bolje, ali ja sam lenj.

Još malo glavolomnog sadržaja vezanog za kvantnu teoriju i vreme:

Quantum Experiment Shows How Time 'Emerges' from Entanglement (https://medium.com/the-physics-arxiv-blog/d5d3dc850933)

Quote
Time is an emergent phenomenon that is a side effect of quantum entanglement, say physicists. And they have the first experimental results to prove itWhen the new ideas of quantum mechanics spread through science like wildfire in the first half of the 20th century, one of the first things physicists did was to apply them to gravity and general relativity. The result were not pretty.
It immediately became clear that these two foundations of modern physics were entirely incompatible. When physicists attempted to meld the approaches, the resulting equations were bedeviled with infinities making it impossible to make sense of the results.
Then in the mid-1960s, there was a breakthrough. The physicists John Wheeler and Bryce DeWitt successfully combined the previously incompatible ideas in a key result that has since become known as the Wheeler-DeWitt equation. This is important because it avoids the troublesome infinites—a huge advance.
But it didn't take physicists long to realise that while the Wheeler-DeWitt equation solved one significant problem, it introduced another. The new problem was that time played no role in this equation. In effect, it says that nothing ever happens in the universe, a prediction that is clearly at odds with the observational evidence.
This conundrum, which physicists call 'the problem of time', has proved to be thorn in flesh of modern physicists, who have tried to ignore it but with little success.
Then in 1983, the theorists Don Page and William Wooters came up with a novel solution based on the quantum phenomenon of entanglement. This is the exotic property in which two quantum particles share the same existence, even though they are physically separated.
Entanglement is a deep and powerful link and Page and Wooters showed how it can be used to measure time. Their idea was that the way a pair of entangled particles evolve is a kind of clock that can be used to measure change.
But the results depend on how the observation is made. One way to do this is to compare the change in the entangled particles with an external clock that is entirely independent of the universe. This is equivalent to god-like observer outside the universe measuring the evolution of the particles using an external clock.
In this case, Page and Wooters showed that the particles would appear entirely unchanging—that time would not exist in this scenario.
But there is another way to do it that gives a different result. This is for an observer inside the universe to compare the evolution of the particles with the rest of the universe. In this case, the internal observer would see a change and this difference in the evolution of entangled particles compared with everything else is an important a measure of time.
This is an elegant and powerful idea. It suggests that time is an emergent phenomenon that comes about because of the nature of entanglement. And it exists only for observers inside the universe. Any god-like observer outside sees a static, unchanging universe, just as the Wheeler-DeWitt equations predict.
Of course, without experimental verification, Page and Wooter's ideas are little more than a philosophical curiosity. And since it is never possible to have an observer outside the universe, there seemed little chance of ever testing the idea.
Until now. Today, Ekaterina Moreva at the Istituto Nazionale di Ricerca Metrologica (INRIM) in Turin, Italy, and a few pals have performed the first experimental test of Page Wooters ideas. And they confirm that time is indeed an emergent phenomenon for 'internal' observers but absent for external ones.
The experiment involves the creation of a toy universe consisting of a pair of entangled photons and an observer that can measure their state in one of two ways. In the first, the observer measures the evolution of the system by becoming entangled with it. In the second, a god-like observer measures the evolution against an external clock which is entirely independent of the toy universe.
The experimental details are straightforward. The entangled photons each have a polarisation which can be changed by passing it through a birefringent plate. In the first set up, the observer measures the polarisation of one photon, thereby becoming entangled with it. He or she then compares this with the polarisation of the second photon. The difference is a measure of time.
In the second set up, the photons again both pass through the birefringent plates which change their polarisations. However, in this case, the observer only measures the global properties of both photons by comparing them against an independent clock.
In this case, the observer cannot detect any difference between the photons without becoming entangled with one or the other. And if there is no difference, the system appears static. In other words, time does not emerge.
"Although extremely simple, our model captures the two, seemingly contradictory, properties of the Page-Wooters mechanism," say Moreva and co.
That's an impressive experiment. Emergence is a popular idea in science. In particular, physicists have recently become excited about the idea that gravity is an emergent phenomenon. So it's a relatively small step to think that time may emerge in a similar way.
What emergent gravity has lacked, of course, is an experimental demonstration that shows how it works in in practice. That's why Moreva and co's work is significant. It places an abstract and exotic idea on firm experimental footing for the first time.
Perhaps most significant of all is the implication that quantum mechanics and general relativity are not so incompatible after all. When viewed through the lens of entanglement, the famous 'problem of time' just melts away.
The next step will to extend the idea further, particularly to the macroscopic scale. It's one thing to show how time emerges for photons, it's quite another to show how it emerges for larger things such as humans and train timetables.
And therein lies another challenge.
Ref: arxiv.org/abs/1310.4691 (http://arxiv.org/abs/1310.4691) :Time From Quantum Entanglement: An Experimental Illustration

Veza između kvantne zapletenosti i crvotočina u kosmosu se pomalja i ako ova teorija zaživi na putu smo da pomirimo kvantnu teoriju sa Ajnštajnovom opštom teorijom relativiteta. Doduše, kritičari teorije vele da je u pitanju prosta matematička sličnost koja ne ukazuje na povezanost.

       

    A Link Between Wormholes and Quantum Entanglement (http://news.sciencemag.org/physics/2013/12/link-between-wormholes-and-quantum-entanglement)   

Quote
  This advance is so meta. Theoretical physicists have forged a connection between the concept of entanglement (http://news.sciencemag.org/2013/05/physicists-create-quantum-link-between-photons-dont-exist-same-time)—itself a mysterious quantum mechanical connection between two widely separated particles—and that of a wormhole—a hypothetical connection between black holes that serves as a shortcut through space. The insight could help physicists reconcile quantum mechanics and Einstein's general theory of relativity, perhaps the grandest goal in theoretical physics. But some experts argue that the connection is merely a mathematical analogy.
Entanglement links quantum particles so that fiddling with one can instantly affect another. According to the bizarre quantum laws that govern the subatomic realm, a tiny particle can be in two opposite conditions or states at once. For example, an atom can spin in one direction or the other—up or down—or both ways at once. That two-way state lasts only until the atom's spin is measured, however, at which point it "collapses" into either the up or down state. Two atoms can then be entangled so that both spin two ways at once but their spins are completely correlated, so that, for example, they point in opposite directions. Then, if the first atom is measured and found to be spin up, the second atom will instantly collapse into the down state, even if it's light-years away.
Wormholes, on the other hand, are a prediction of Albert Einstein's general theory of relativity, which describes how massive objects warp space and time, or spacetime, to create the effects we call gravity. If an object is massive enough, it can create a funnellike hole in spacetime so steep that not even light can escape from it—a black hole. In principle, two widely separated black holes can connect like back-to-back trumpet horns to make a shortcut through spacetime called a wormhole.
At first glance, entanglement and wormholes both seem to offer a way around Einstein's dictum that nothing can travel faster than light. But in both cases, that hope is dashed. Entanglement cannot be used to send signals faster than light because one cannot control the output of the measurement on the first atom and thus willfully set the state of the distant one. Similarly, one can't zip through a wormhole because it's impossible to escape the black hole on the other end. Still, there is a connection. In June, Juan Maldacena, a theorist at the Institute for Advanced Study in Princeton, New Jersey, and Leonard Susskind, a theorist at Stanford University in Palo Alto, California, imagined entangling the quantum states of two black holes. They then imagined pulling the black holes apart. When that happens, they argued, a bona fide wormhole forms between the two black holes.
That was perhaps not so surprising, because the researchers started with black holes. But now two independent teams of scientists say that it should also be possible to create a wormhole connection between two ordinary quantum particles, such as quarks that make up protons and neutrons.
Kristan Jensen of the University of Victoria in Canada and Andreas Karch of the University of Washington, Seattle, start by imagining an entangled quark-antiquark pair residing in ordinary 3D space (http://prl.aps.org/abstract/PRL/v111/i21/e211602), as they described online on 20 November in Physical Review Letters. The two quarks rush away from each other, approaching the speed of light so that it becomes impossible to pass signals from one to the other. The researchers assume that the 3D space where the quarks reside is a hypothetical boundary of a 4D world. In this 3D space, the entangled pair is connected by a kind of conceptual string. But in the 4D space, the string becomes a wormhole.
Julian Sonner of the Massachusetts Institute of Technology in Cambridge then builds upon Karch's and Jensen's work. He imagines a quark-antiquark pair that pops into existence in a strong electric field (http://prl.aps.org/abstract/PRL/v111/i21/e211603), which then sends the oppositely charged particles accelerating in opposite directions. Sonner also finds that the entangled particles in the 3D world are connected by a wormhole in the 4D world, as he also reported online on 20 November in Physical Review Letters.
To arrive at this result, Jensen, Karch, and Sonner use the so-called holographic principle, a concept invented by Maldacena that states that a quantum theory with gravity in a given space is equivalent to a quantum theory without gravity in a space with one less dimension that makes up the original space's boundary. In other words, black holes inside the 4D space and a wormhole between them are mathematically equivalent to their holographic projections existing on the boundary in 3D. These projections are essentially elementary particles that function according to the laws of quantum mechanics, without gravity, and a string connecting them. "The wormhole and entangled pair don't live in the same space," Karch says. But, he adds, mathematically they are equivalent.
But how big an insight is this? It depends on whom you ask. Susskind and Maldacena note that in both papers, the original quantum particles reside in a space without gravity. In a simplified, gravity-free 3D model of our world, there can't be any black holes or wormholes, Susskind adds, so the connection to a wormhole in a higher dimensional space is mere mathematical analogy. The wormhole and entanglement equivalence "only makes sense in a theory with gravity," Susskind says.
However, Karch and colleagues say that their calculations are an important first step toward verifying Maldacena and Susskind's theory. Their toy model without gravity, Karch says, "gives a concrete realization of the idea that wormhole geometry and entanglement can be different manifestations of the same physical reality."
   

http://prl.aps.org/abstract/PRL/v111/i21/e211602 (http://prl.aps.org/abstract/PRL/v111/i21/e211602)

http://prl.aps.org/abstract/PRL/v111/i21/e211603 (http://prl.aps.org/abstract/PRL/v111/i21/e211603)

Why we think there's a Multiverse, not just our Universe (https://medium.com/starts-with-a-bang/23d5ecd33707)


(Ne mogu da ga kopiram, ima previše slika i grafikona. Da ne pominjem jednačine  :-? :-? :-? :-? )

Čitaš li ti Skrobonju?  :)

Pa... ne? Zašto?

Pa, multiverzumi...

More, čitaš li TI Skrobonju?


ed. Dobro, de, jedan multiverzum, ali multiverzumi!!!! To je još jednačina.

Mene pitaš, čitam li Skrobonju?

Pa, pročitao sam do sada praktično sve što je napisao, osim poslednjeg romana Sva Teslina deca, koga mi je poslao u fazi rada na njemu da mu dam sugestije, ali zbog zauzetosti nisam uspeo da stignem da pročitam više od stotinak stranica, a on se već pojavio u štampi. Zato sam prestao da ga čitam, pa ću ga natenane pročitati, od početka, u finalnoj obradi, na nekom od odmora...


Ne verujem da postoji u galaksiji čovek koji je pročitao više Skorobonjog originalnog teksta (lilit uključujući, ma koliko to nemoguće zvučalo)...


Kad je pravio bibliografiju svojih ostvarenja dodao sam mu priču za koju ni sam nije znao da ju je napisao...


Mene pitaš čitam li Skrobonju?

Ja sam koncept multiverzuma svario čitajući Murkoka, a posle X-Men i Marvelove stripove generalno tako da je meni to što bi se reklo "normalna stvar".

Duboko se izvinjavam.


Učinilo mi se da sam osetio dozu iznenađenja u tvom postu, pa plaho reagovah...

Oh, ne, ne, nema mesta izvinjavanju. Moje izbezumljene face (simbolizovane smajlijima) su tu bile zbog količine matematike u tekstu koji sam linkovao a koja zahteva da se čovek malo ozbiljnije udubi u čitanje ako želi da razume zaključak koji veli: "eto, zato postoji multiverzum".

Nego da te pitam. Ti meni napišeš da ne čitam ništa, pa mirna Bačka. Eto, pročitao si stotinak strana Skrobonje više od mene. Mene je više zanimala priča o multiverzumima. Jel' to znači da ima više multiverzuma? Mada bi mogao da mi objasni i Meho. On je to apsolvirao kod Murkoka i Marvela.

Da pojasnim da u tekstu koji sam linkovao pominju samo multiverzum, ne multiverzume. To je Mića u šali rekao "multiverzumi".

Što se tiče Murkoka, meni je kao detetu bilo skroz mindblowing kada sam video da se likovi iz očigledno različitih univerzuma u nekim momentima susreću, pa još kada se ispostavilo da su neki od njih različite verzije istog arhetipskog like  :-? :-? :-?


Kod Marvela (i kod konkurencije u DC-ju) je koncept multiverzuma uglavnom korišćen kao narativna poštapalica koja se upotrebi kada ne možeš neku priču da ispričaš u "glavnom" univerzumu jer njeni događaji protivreče uspostavljenoj istoriji tog sveta. Mada je bilo i inventivnijih korišćenja, naravno. Kod DC-ja je recimo bilo interesantno gledati kako je polovinom osamdesetih urađen veliki pokušaj pakovanja svih univerzuma u jedan i uređivanja istorije da bude konzistentna...

Nije bilo u šali. Skrobonja piše o multiverzumima. Meni je multiverzum uvek pomalo bio posledica racionalizacije putovanja kroz vreme: ako već putujemo kroz vreme i tako menjamo realnost, sasvim je očekivano da ta nova realnost pripada drugom univerzumu. Ovo sa jednačinama je nova racionalizacija nastala iz iste ideje.

Aha. A kako se multiverzumi kod Skrobonje razlikuju/ klasifikuju?

Ofrlje.

Pa, ne, mislim, koji je razlog za postojanje više od jednog multiverzuma?? Kako je to književno opravdano?

Ove pravoslavne godine u svemu se slažemo.


Postoji još jedno pričanje o multiverzumu (drugom), ali taj je moja ujdurma. Ni to nisi čitao.

Ali možeš da mi pojasniš kako si ti onda opravdao postojanje više od jednog multiverzuma. Mislim, ja ne uspevam da izmaštam kako bi postojalo više od jednog.

Borhesov "Vrt sa stazama koje se račvaju". Paralelni univerzumi. Koristili su to mnogi. Jan Mekdonald ti je neki od modernijih primera. SF klasika...

Paralelni univerzumi su multiverzum. Ali šta su multiverzumi, kako se oni račvaju?


Mekdonalda sam pročitao dva romana i ni jedan nije imao koncept multiverzuma pa mi ova referenca ne pomaže  :( :(

Ako si mene pitao, onda ćeš morati da pročitaš moje Svemirske Cigane (obe knjige). Ili pitaj Miću. On sigurno zna. Ako nije zaboravio.

Pa, da, prvo mi zaglicate maštu a onda kao "ko te jebe, čitaj knjige". Pa da sam hteo da čitam knjige, ne bih se doseljavao na internet!!!!

Što si onda pročitao DVA Mekdonalda?

Možda su dva multiverzuma multiverzum, kao što je dvaput beskonačno beskonačno.

Quote from: scallop on 14-01-2014, 12:33:31
Što si onda pročitao DVA Mekdonalda?

Navukli me mangupi. Skrobonja ga je mnogo hajpovao i onda je Nekrovil pojavio u Monolitu i ja kao, ajde, Monolit je to, Boban me nikad do sad nije prevario i onda kao, budućnost, zombiji, genetkiinženjeringkrilaludilopewpewništanisamshvatio. A čitao sam i Desolation Road jer ga je DrZŽ objavio u svojoj biblioteci a tu sam računao, DrZŽ je ipak naš čovek, old skul lik, ne bi on ovo objavio da nije valjano. Ali nije me ni to baš kupilo. Od svega što sam pročitao od Mekdonalda (a čitao sam još nekoliko priča) dopala mi se samo ona jedna priča gde se irski đilkoš smuva sa vanzemaljkom koja odlepi od seksualne želje kad god oseti miris njegove kožne jakne a posle je ubije IRA. Tako da je moje ponovljeno razočaranje u najhajpovanijeg pisca na ovim prostorima tokom devedesetih godina bilo dosta zaslužno za to da se odreknem knjiga i prigrlim ambis interneta.

Quote from: Father Jape on 14-01-2014, 12:38:41
Možda su dva multiverzuma multiverzum, kao što je dvaput beskonačno beskonačno.

Pa to je i moj rezon. Zato i pitam koji je kriterijum da se prepoznaju dva distinktna multiverzuma a ne samo jedan. Primera radi, kriterijum za razlikovanje dva univerzuma bi bilo recimo to da u njima neka fizička konstanta nema jednaku vrednost - na primer, brzina svetlosti u našem je 300k kilometara u sekundi a u drugom je svega 300 metara, pa to ima silne druge implikacije itd. Ali pošto multiverzum (jedan) već, kao koncept obuhvata sve takve varijacije - barem kako ja mogu da ih zamislim - onda me zbunjuje po čemu se onda razlikuje drugi multiverzum.

I sad mi je Mekdonald kriv što ne čitaš? I Mića koji ladno napiše da je SF klasik. Bre, Boban i ja smo klasika za Mekdonalda. Inače, u pravu si kad napišeš da bi drugi multiverzum morao da bude zasnovan na bar jednom parametru koji nije svojstven našem multiverzumu.

Nije samo Mekdonald, najviše je kriva moja pretencioznost, kada sam odlučio da moram da čitam više teorije pa je sad ispalo da čitam maltene samo teoriju.

Mislim da je Mića Mekdonalda nazvao modernijim primerom, a da je opaska o klasici bila vezana za nešto drugo što bih morao da sam znam bez navođenja.

I, da, to za kriterijum me i zanima. Dakle, dajte da to raspravimo, kako se razlikuju dva multiverzuma?

Evo jedne lake podele. Svi univerzumi u koje može da prodre informacija iz drugog univerzuma čine skup koji je jedan multiverzum. Svi univerzumi za koje to ne važi su neki drugi multiverzum (ili multiverzumi).

mac, je l ovo tvoja podela, ili neka opšte prihvaćena?

Ma moja. Cela ta priča o multiverzumu je u ovom trenutku vrlo mutna, malo šta se zna, osim da postoji, a i to se ne zna empirijski, tako da pretpostavke lete na sve strane kao neutrini.

Podela nije loša za moj groš, mada jeste arbitrarna. Mislim, može i da se kaže da su univerzumi koji međusobno komuniciraju podskup unutar jednog multiverzuma - dakle, ova vrsta kriterijuma ne daje nužno više od jednog multiverzuma (drugi kriterijum može da bude takođe arbitraran - svi univerzumi u kojima je plankova konstanta manja od te i te vrednosti su jedan multiverzum, svi u kojima je veća su drugi, pošto vrednost plankove konstante određuje veličinu kvanta pa to onda ima uticaja na sve ostale vrednosti u univerzumu. ). Neki... jači kriterijum bi mi bio uverljiviji.

Eto, nekima je sasvim lako. Otprilike to što je napisao Mac napisao je i Hoking, jedino je Hoking bio skroman, pa se ograničio na univerzum. Dakle, njegovo tumačenje je analogija Hokingovog.


Sa druge strane, mi bismo mogli da se bacimo i na problematiku multiverzuma, ali ovaj forum je suviše neozbiljno mesto. Naravno, pišem samo sa tačke gledišta fantastike, da budem precizniji, naučne fantastike. Za mene se pitanje multiverzuma ne rešava sa nekoliko jednačina i crteža. Ono, zaista, mora da počiva na elementima koje ne može da pokrije jedan multiverzum. Tvoj stav da bi to mogla da bude bar brzina svetlosti od 300 m/s je relevantan. Naravno, to može da bude zanimljiva pozicija, ali ostaje pitanje šta nam bitno donosi. Nešto što se u fantastici, posebno u domaćoj fantastici, više ne posmatra celishodnim, jeste upravo pitanje zašto?, ili šta nam novo donosi. Mislim da je neko ovde pomenuo, ali smo to olako preskočili, fantastika sadrži i kriterijume uverljivosti koje realna književnost nema kao problem.


Sa treće strane, imam ja i svoju teoriju za pristupanje fantastici, držim se toga kao premise u pisanju, ali to što se događa u našem selu nikoga ne zanima. Mislim da sam u jednom kraćem tekstu sve sažeo kao lični pristup naučnoj fantastici, čak ga je ZStef. negde i postavio, ali to niko ne vidi od silnih linkova na engleskom jeziku. Možda je najbolje da se uzdržim i da prepustim naknadnom kopanju.

Da, pa ja sam ideju o brzini svetlosti od 300 metara u sekundi i pomenuo upravo kao nešto što mi deluje kao polazna osnova za pisanje fantastične proze koja bi iz ove premise (možda) mogla da izvuče posledice koje bi prevazišle puke "fizičke" razlike između našeg i tog univerzuma. Lem je, recimo imao onu sjajnu priču koja nije imala multiverzalnu premisu ali je bila bazirana na ideji da naučnici otkrivaju živa bića u vreloj, jelte, plazmi i onda razvijaju tezu da zapravo, zbog visokog energetskog sadržaja takvog okruženja (ili tako nešto), život u našem univerzumu, načelno, po pravilu nastaje upravo u koronama zvezda itd. te da je naše postojanje u komparativno ledenom delu univerzuma, dakle, predaleko od zvezde, anomalija i, kako već to kod Lema biva, dolazi se do zaključka da smo mi time osuđeni na otpadništvo, da nikada nećemo ni naći način da komuniciramo sa većinskom populacijom svemira jer u odnosu na njih živimo nekoliko potencija presporim tempom i ona nas ne bi ni prepoznala kao živa bića itd.

Sad me povlačiš tamo gde ja ne bih. Vreme Lema, Klarka pa i nekih drugih je vreme stvaranja okvira za fantastične priče. To je vreme antiantropomorfije kojoj se Z.Ž. toliko divio, a BoB postavio pitanje: "Šta mene briga što je stonoga slomila 76 nogu levo?". Što se mene tiče, BoB je apsolutno bio u pravu. Takođe, priča o irskom đilkošu je ljudskija i pripada vremenu promenjene uznapredovale fantastike. Ako promenimo sredinu ili pomerimo vreme, u središtu je i dalje ono šta se događa nama. Ako danas menjamo ili postavljamo nove okvire, ta promena se događa samo zato da bismo dobili drugačije uslove, ali u njima i dalje posmatramo ljude i njihove odnose.

Ma, dobro, pomenuo sam Lema jer mi je prvo palo na pamet kako varijacija na jednu stvar u vezi sa prirodom dovodi do velike metafizičke posledice (i to kod njega čak unutar istog univerzuma). Ja se svakako slažem sa tobom u tome da bi proza koja bi pre svega ispitivala suhe fizičke posledice promene nekog od parametara meni bila manje zanimljiva od one koja bi u to unela hjumen tač, zato sam gore i pomenuo "pisanje fantastične proze koja bi iz ove premise (možda) mogla da izvuče posledice koje bi prevazišle puke "fizičke" razlike između našeg i tog univerzuma".

Opet, ne mislim da to nužno treba da budu stvari na razini emocija ili kakve socijalne proze, mada je i to apsolutno legitiman pristup. Kad razmišljam o SF delima koja su mi bila fascinantna na ime neke radikalne "naučne" premise često se prisetim onih koja su to pre svega na tom nekom metafizičkom nivou - od recimo Andersonovog Tau zero (koji pokazuje ljude koji prežive kraj jednog univerzuma, novi veliki prasak i pojave se u novom univerzumu), pa preko Priestovog Invertiranog sveta (koji ima elemente socijalne proze (klasno uređenje društva, strukture moći koje tu moć ne puštaju jer insistiraju da je jedino ovakav način života kadar da obezbedi opstanak) kojima nas navuče da navijamo za glavnog junaka za koga se nadamo da će revolucijom poremetiti status quo samo da bi nas na kraju ošamario prikazom da su zapravo strukture moći u pravu i da junaci žive u jednom skoro pa nezamislivom svetu), sve do nebrojenih priča kojima više ne pamtim ni imena ni autore ali su mi se urezale u sećanje tim jakim opisima svetova koji su radikalno drugačiji od našeg najčešće po samo jednom parametru, ali taj parametar menja sve i ljudsku egzistenciju dovodi u mnogo oštriji fokus (bila je jedna u Siriujusu u kojoj neobjašjivo, gravitacija jedog dana počne da deluje pod uglom od devedeset stepeni... pa onda jedna u Alefu o narodu koji živi na litici, bukvalno provodeći čitav život, gradeći društvo, porodice itd. na vertikalnoj površini).

ван топика: мехо која је то лемова прича, не сећам је се, а радо бих је прочитао.

Nadam se da naslova mogu da se sete neki manje izlapeli ljudi od mene. Ako se dobro sećam, izašla je u nekom Monolitu, ali pregledanjem ovog topika (http://www.znaksagite.com/diskusije/index.php?topic=2632.0) naišao sam samo na priču "Čekić" a nisam siguran da je to ta.

Edit: nije to ta, evo čekića u originalu (http://leeet.net/lib/getfile.php?id=26970). Grrr, ne sećam se kako se ova zvala...

Tačno. U jednom trenutku, pored toga što svet mora da bude argumentovan, isplivava i kako se to odražava na populaciju koja u tim uslovima živi. Mada bismo mogli jeretički da tvrdimo da uslove u pomerenom svetu i vremenu autor postavlja da bi ispisao svoju priču. Znači da nas već nekoliko decenija autori ne impresioniraju pomeranjem sveta ili vremena u kojima se priča događa, već pričom koja se u tim uslovima odvija. Neko bi sad zaključio da više nije SF klasika, što i nije, već da je to fentezi u sredini koja je već jednom iscrtana. Smatram da se tu upeljavamo u klasifikacije umesto da jednostavno objasnimo da je Suvinova definicija novuma možda zasnovana na hitro odabranoj odrednici. Pojam novuma svakako ima svoju težinu, ali pomislimo da li je savršena priča, zasnovana na već iskorišćenom novumu, samo fentezi? Da li je Papinijeva Istorija o Hristu samo apokrif ili je izvrsna literatura? Imam osećaj da je pojam novuma pomalo prevaziđen i da se zbog gotovo religioznog sledbeništva utapamo u suvišnim klasifikacijama.


Prelazak na aktuelne klasifikacije može da sačeka dok se proguta ovo do sada.

Pa, ja sad ne smem da se usudim da raspravljam o novumu u savremenoj fantastici (naučnoj i inoj) jer je moj uvid u moderni fantastički literarni korpus jednak nuli. Ali čisto instinktivno ću se složiti da je, ako pričamo o literaturi koja bi trebalo da bude smatrana dobrom, primarno ne to kako opisati drugačiji svet/ univerzum/ multiverzum već kako se ta drugačijost odražava na, jelte, hjumen kondišn. I sam Asimov je u predgovoru za Nightfall eksplicitno insistirao da iako stanovnici planete koju opisuje možda nisu "stvarno" antropomorfni, za potrebe usredsređivanja na interesantne sociološke posledice njegove naučnofantastične premise (svet sa više sunaca u kome (skoro) nikada ne pada noć, a noć ipak dolazi) rešio je da se ne bakće sa opisivanjem njihovih pipaka ili bizarnih rituala parenja, već da je dovoljno da čitalac zamišlja da su oni dovoljno uporedivi sa nama, kako bi ispratio priču na pravi način.

Opet, s druge strane - i neka mi bude oprošteno što navodim samo primere iz duboke prošlosti - sam Asimov u romanu Gods themselves ima element koji je, da kažem, sociološki interesantan u smislu toga kako mase percipiraju nauku kao utilitarnu disciplinu koju zapravo ne razumeju i zbog toga često naučnike raspinju na križ itd., ali je sa druge strane imao i element opisivanja paralelnog univerzuma koji ima društvo (i biologiju, i fiziku) neuporedivo sa našim i, ako mogu da kažem, kontrast tog društva sa našim nije neophodan da bi se ispričala ova druga strana priče u romanu (ova u našem univerzumu, na našoj zemlji) ali ga obogaćuje.

Skoro sam videla ovu animaciju

Stephen Hawking's big ideas... made simple - animation (http://www.youtube.com/watch?v=D6lFGJdwRyo#ws)

A kad ste vec pomenuli Asimova evo jos nesto lepo za citanje

http://www.brainpickings.org/index.php/2013/04/04/isaac-asimov-muppets-magazine-1983/ (http://www.brainpickings.org/index.php/2013/04/04/isaac-asimov-muppets-magazine-1983/)

Shvatam da te napinjem, pa ću da odustanem. Da ne pominjem trolovanje sa strane.

Ma, napinjem se sam, mislim, najnovije delo naučne fantastike koje sam pročitao verovatno je staro dve decenije... Izvan tokova sam.

Stiven Hoking elegantno rešava probleme koje naučnici već decenijama imaju u vezisa horizontom događaja crne rupe a gde se Ajnštajnova teorija relativnosti i kvantna teorija sudaraju uz tresak. Hoking šeretski veli: ne postoje crne rupe.

Stephen Hawking: 'There are no black holes' (http://www.nature.com/news/stephen-hawking-there-are-no-black-holes-1.14583)

Quote
Notion of an 'event horizon', from which nothing can escape, is incompatible with quantum theory, physicist claims.
 

Most physicists foolhardy enough to write a paper claiming that "there are no black holes" — at least not in the sense we usually imagine — would probably be dismissed as cranks. But when the call to redefine these cosmic crunchers comes from Stephen Hawking, it's worth taking notice. In a paper posted online, the physicist, based at the University of Cambridge, UK, and one of the creators of modern black-hole theory, does away with the notion of an event horizon, the invisible boundary thought to shroud every black hole, beyond which nothing, not even light, can escape.

In its stead, Hawking's radical proposal is a much more benign "apparent horizon", which only temporarily holds matter and energy prisoner before eventually releasing them, albeit in a more garbled form.
                                                           
"There is no escape from a black hole in classical theory," Hawking told Nature. Quantum theory, however, "enables energy and information to escape from a black hole". A full explanation of the process, the physicist admits, would require a theory that successfully merges gravity with the other fundamental forces of nature. But that is a goal that has eluded physicists for nearly a century. "The correct treatment," Hawking says, "remains a mystery."
                                                           
Hawking posted his paper on the arXiv (http://arxiv.org/abs/1401.5761) preprint server on 22 January^{1 (http://www.nature.com/news/stephen-hawking-there-are-no-black-holes-1.14583#b1)}. He titled it, whimsically, 'Information preservation and weather forecasting for black holes', and it has yet to pass peer review. The paper was based on a talk he gave via Skype at a meeting at the Kavli Institute for Theoretical Physics in Santa Barbara, California, in August 2013 (watch video of the talk (http://online.kitp.ucsb.edu/online/fuzzorfire_m13/hawking/)).
                                                            Fire fighting                                                           
Hawking's new work is an attempt to solve what is known as the black-hole firewall paradox, which has been vexing physicists for almost two years, after it was discovered by theoretical physicist Joseph Polchinski of the Kavli Institute and his colleagues (see 'Astrophysics: Fire in the hole! (http://www.nature.com/news/astrophysics-fire-in-the-hole-1.12726)').
                                                           
In a thought experiment, the researchers asked what would happen to an astronaut unlucky enough to fall into a black hole. Event horizons are mathematically simple consequences of Einstein's general theory of relativity that were first pointed out by the German astronomer Karl Schwarzschild in a letter he wrote to Einstein (http://alberteinstein.info/vufind1/Record/EAR000006266) in late 1915, less than a month after the publication of the theory. In that picture, physicists had long assumed, the astronaut would happily pass through the event horizon, unaware of his or her impending doom, before gradually being pulled inwards — stretched out along the way, like spaghetti — and eventually crushed at the 'singularity', the black hole's hypothetical infinitely dense core.

But on analysing the situation in detail, Polchinski's team came to the startling realization that the laws of quantum mechanics, which govern particles on small scales, change the situation completely. Quantum theory, they said, dictates that the event horizon must actually be transformed into a highly energetic region, or 'firewall', that would burn the astronaut to a crisp.
This was alarming because, although the firewall obeyed quantum rules, it flouted Einstein's general theory of relativity. According to that theory, someone in free fall should perceive the laws of physics as being identical everywhere in the Universe — whether they are falling into a black hole or floating in empty intergalactic space. As far as Einstein is concerned, the event horizon should be an unremarkable place.
   Beyond the horizon                                                            Now Hawking proposes a third, tantalizingly simple, option. Quantum mechanics and general relativity remain intact, but black holes simply do not have an event horizon to catch fire. The key to his claim is that quantum effects around the black hole cause space-time to fluctuate too wildly for a sharp boundary surface to exist.
In place of the event horizon, Hawking invokes an "apparent horizon", a surface along which light rays attempting to rush away from the black hole's core will be suspended. In general relativity, for an unchanging black hole, these two horizons are identical, because light trying to escape from inside a black hole can reach only as far as the event horizon and will be held there, as though stuck on a treadmill. However, the two horizons can, in principle, be distinguished. If more matter gets swallowed by the black hole, its event horizon will swell and grow larger than the apparent horizon.
Conversely, in the 1970s, Hawking also showed that black holes can slowly shrink, spewing out 'Hawking radiation'. In that case, the event horizon would, in theory, become smaller than the apparent horizon. Hawking's new suggestion is that the apparent horizon is the real boundary. "The absence of event horizons means that there are no black holes — in the sense of regimes from which light can't escape to infinity," Hawking writes.
"The picture Hawking gives sounds reasonable," says Don Page, a physicist and expert on black holes at the University of Alberta in Edmonton, Canada, who collaborated with Hawking in the 1970s. "You could say that it is radical to propose there's no event horizon. But these are highly quantum conditions, and there's ambiguity about what space-time even is, let alone whether there is a definite region that can be marked as an event horizon."
Although Page accepts Hawking's proposal that a black hole could exist without an event horizon, he questions whether that alone is enough to get past the firewall paradox. The presence of even an ephemeral apparent horizon, he cautions, could well cause the same problems as does an event horizon.
Unlike the event horizon, the apparent horizon can eventually dissolve. Page notes that Hawking is opening the door to a scenario so extreme "that anything in principle can get out of a black hole". Although Hawking does not specify in his paper exactly how an apparent horizon would disappear, Page speculates that when it has shrunk to a certain size, at which the effects of both quantum mechanics and gravity combine, it is plausible that it could vanish. At that point, whatever was once trapped within the black hole would be released (although not in good shape).
If Hawking is correct, there could even be no singularity at the core of the black hole. Instead, matter would be only temporarily held behind the apparent horizon, which would gradually move inward owing to the pull of the black hole, but would never quite crunch down to the centre. Information about this matter would not destroyed, but would be highly scrambled so that, as it is released through Hawking radiation, it would be in a vastly different form, making it almost impossible to work out what the swallowed objects once were.
"It would be worse than trying to reconstruct a book that you burned from its ashes," says Page. In his paper, Hawking compares it to trying to forecast the weather ahead of time: in theory it is possible, but in practice it is too difficult to do with much accuracy.
Polchinski, however, is sceptical that black holes without an event horizon could exist in nature. The kind of violent fluctuations needed to erase it are too rare in the Universe, he says. "In Einstein's gravity, the black-hole horizon is not so different from any other part of space," says Polchinski. "We never see space-time fluctuate in our own neighbourhood: it is just too rare on large scales."
Raphael Bousso, a theoretical physicist at the University of California, Berkeley, and a former student of Hawking's, says that this latest contribution highlights how "abhorrent" physicists find the potential existence of firewalls. However, he is also cautious about Hawking's solution. "The idea that there are no points from which you cannot escape a black hole is in some ways an even more radical and problematic suggestion than the existence of firewalls," he says. "But the fact that we're still discussing such questions 40 years after Hawking's first papers on black holes and information is testament to their enormous significance."
   Nature doi:10.1038/nature.2014.14583      References (http://www.znaksagite.com/diskusije/javascript:;) 

   
• Hawking, S. W. Preprint at http://arxiv.org/abs/1401.5761 (http://arxiv.org/abs/1401.5761) (2014).

I reakcija na Hokinga


Yes, Virginia, Black Holes Exist! (https://medium.com/starts-with-a-bang/df0a131d7b95)

Quote
Do black holes exist? The world's most famous scientist vs. the actual science.

"My goal is simple. It is a complete understanding of the Universe, why it is as it is and why it exists at all." -Stephen Hawking

Here in our little corner of the Universe, the Earth is a pretty intense source of gravity for us. If we want to escape its gravitational pull, we'd need to accelerate ourselves up past the escape velocity (http://en.wikipedia.org/wiki/Escape_velocity), or the speed necessary to climb out of the gravitational potential well that Earth's mass creates. We can (and have) accomplished this, in fact, but it would take a speed of around 11.2 km/s (or 0.004% the speed of light) to make it so.






But that's not so fast, after all, not compared to a great many things in this Universe. The reason that we don't need higher speeds to escape from our planet is that despite having a decent amount of mass — some 6 × 10^24 kg, or some 10^49 heavy atoms — our Earth is spread out over a relatively large volume of space.
But if the laws of physics were somewhat different, we might be able to compress the mass of our Earth down into a much smaller region of space. And if we could, it would take greater and greater speeds to escape from it. At some point, when all the mass of the Earth was compressed into a sphere a little smaller than a centimeter in radius, you'd suddenly discover that nothing in this Universe — not even light — could escape from it.
You'd have turned the Earth into a black hole.




Because the speed of light in a vacuum is a universal speed limit, some regions of space can achieve enough mass compressed into a small enough volume that nothing can escape from it (https://medium.com/starts-with-a-bang/43e9e3401513). For a long time, these were purely theoretical objects, as it was assumed that getting such huge amounts of mass into such a tiny volume would be impossible. But then we started discovering things that were... interesting.
Regions of space with incredible radio and X-ray emissions, but no visible light. Regions where stars were being ripped apart and their matter accelerated, but no signs of ultramassive stars. And finally, a place near the very center of our galaxy where stars were orbiting a single point that must have a mass of around 4 million Suns, but from which no light of any type was being emitted.
This must be a black hole! Gravitationally, Einstein's theory of General Relativity tells us that black holes must distort space, with interesting optical effects that can will show up by looking at the background matter.


But you might wonder, thinking about objects like this, whether they're really, truly, completely black, in the sense that nothing can ever escape from them. It's a legitimate question, and one that didn't really go answered for a very long time. You see, black holes — as described by Einstein's theory of gravity — were classical objects, or objects described by a continuous spacetime with mass, charge, and angular momentum in it. But we know that the matter and energy in our reality is not necessarily continuous in nature, but rather quantum. And there was no good way to reconcile the fundamentally quantum nature of things with a classical theory like General Relativity.



Instead, the Universe itself must be inherently quantum in nature, and yet we do not have a quantum theory of spacetime. In the absence of a quantum theory of gravity, there was only one option if you wanted to know what was happening around a black hole: you'd have to compute the predictions of our quantum Universe — and that's the full-on quantum field theory — in the curved spacetime as predicted by General Relativity.



It wasn't going to be easy. And I know, because I've done the calculation (http://en.wikipedia.org/wiki/Quantum_field_theory_in_curved_spacetime) myself, but I wasn't the first to do so. That honor goes to Stephen Hawking, who — in the mid-1970s — calculated what would happen when you had a fundamentally quantum Universe existing in curved spacetime, and that the curvature of space was due to the presence of a black hole.
You'd have quantum fluctuations, or pairs of particles-and-antiparticles popping in-and-out of existence, while simultaneously having this event horizon nearby, where things could fall in, but nothing could ever get out.


What would sometimes happen, however, is that if you had a fluctuation just outside the event horizon, one of the particles (or antiparticles) would sometimes escape from the black hole, while the other one fell in! Because of the conservation of energy, the black hole had to lose mass, while the escaping radiation's spectrum (and you need quantum field theory to get the spectrum correct) would be a blackbody, and determined by the mass of (and hence curvature near) the black hole! All the other properties — how long the black hole would exist for, the timescales on which it would evaporate, the rate of energy loss — were determined by this phenomenon, which is justly known as Hawking radiation (http://en.wikipedia.org/wiki/Hawking_radiation).


In other words, black holes aren't completely black!




Because we don't yet have a complete, comprehensive theory of quantum gravity, we have to do the best we can with the tools we have: General Relativity as the descriptor of space and time, Quantum Field Theory as the laws governing matter and energy. As you (theoretically) move in towards a black hole, you'll typically pass an accretion disk, you'll find that there's an Innermost Stable Circular Orbit (http://en.wikipedia.org/wiki/Black_hole#X-ray_binaries), and then interior to that, there shouldn't be anything, as the black hole gobbles that up and takes in inside its event horizon in short order. And once you go inside — with the exception of Hawking radiation — nothing can ever leave (https://medium.com/starts-with-a-bang/43e9e3401513).
Unless, of course, as a now-famous paper from two years ago (http://arxiv.org/abs/1207.3123) contended, you get incinerated by a firewall of radiation (https://www.simonsfoundation.org/quanta/20121221-alice-and-bob-meet-the-wall-of-fire/) as you cross the event horizon.




What that paper showed is that all three of the following cannot be simultaneously true:

   
• Hawking radiation is in a pure state.
• The information carried by the radiation is emitted from the region near the horizon, with low energy effective field theory valid beyond some microscopic distance from the horizon.
• The infalling observer encounters nothing unusual at the horizon.

This is an interesting paradox, because we had previously thought that Hawking radiation avoids information loss, the black hole's event horizon is a real entity from which nothing can escape, and there would be no firewall (i.e., "nothing unusual") when you cross the event horizon. Yet, could one of these three things be wrong? And if so, which one?
It's often true that noticing things like this is how physics moves forwards. But it's also true that the resolution to this paradox — or any paradox in science — isn't dependent on what a titanic, famous, authoritative figure in the field says it is. It's dependent on the scientific merits themselves.




But three physicists that you've probably never heard of — Samuel L. Braunstein, Stefano Pirandola, and Karol Życzkowski — came up with an interesting find last year (http://prl.aps.org/abstract/PRL/v110/i10/e101301)! You see, Hawking radiation comes from pairs of entangled quantum particles, one of which "escapes" out into the Universe and the other one of which falls into the black hole. If you break the entanglement, by say, measuring the properties of the one that didn't fall in, a barrier of energetic particles would descend around the event horizon of the black hole; that's where the alleged firewall comes from. You have a particle that went "in" and one that went "out," and they're entangled with one another: hence the paradox.
The fun thing that they found, here, is that the greater the entanglement across the event horizon of the black hole, the later the firewall curtain falls. More entanglement = more time. And in our Universe — as their paper shows (http://prl.aps.org/pdf/PRL/v110/i10/e101301) — entanglement across all black hole event horizons is maximized, which means that the time it takes the firewall curtain-to-fall is... infinite. So that was a clue; it didn't answer everything, but it told us that the problem with the paradox probably isn't that item #3 is wrong.
But then this happened.




In short, this proposal suggests throwing out #2, or the notion of a classical event horizon. Well, maybe that's the case, but it's far from clear that this is even a self-consistent resolution, much less the correct one. I do have to give credit for the astonishingly successful PR move to claim, "There are no black holes," but the quantum nature of our Universe in no way invalidates our notion of a classical event horizon in any way other than the existence of Hawking radiation invalidates it.
On the other hand, if it has been successfully shown that #3 isn't the solution, maybe it's worth looking into #1? That is, we normally think of avoiding information loss (another way of saying that Unitarity (http://en.wikipedia.org/wiki/Unitarity_%28physics%29) is maintained) as being synonymous with giving rise to a pure state of radiation. But what if we could avoid that information loss without the Hawking radiation being in a so-called pure state?
There have been two very interesting papers on that front that — along with the Braunstein, Pirandola and Zyczkowski paper I linked to above — represent (to me) the three biggest developments that have come about since the statement of this paradox. And none of them have names like Hawking or Susskind attached to them.


Imagine you have two pairs of particles with the same momenta, and for both pairs, one particle falls in through the event horizon while the other escapes out. If the two that fall in (and, because they do, you never get to see their information) are each entangled with the ones that escape out, you lose information, as you no longer have that Unitarity property.
But Verlinde and Verlinde (http://arxiv.org/abs/1306.0515) showed that you can do a mathematical (and also Unitary) swap so long as the two pairs have the same momenta as one another. Instead of having an in-out pair and another in-out pair, you can treat them as though they were an in-in pair and an out-out pair, effectively disentangling* them, meaning that there's no longer any entanglement across the horizon, and hence no possibility of a firewall. That was progress, but it didn't demonstrate exactly where the firewall paradox broke down.




Until, quite recently, Sabine Hossenfelder found quite generally (http://arxiv.org/abs/1401.0288) that the information preserving transformations you can do also have some generic and incredibly interesting properties:

   
• The swap to disentangle the particles — so that there's no information crossing the event horizon — can be local, meaning it can happen between two points that are causally connected at all times.
• This local interaction is restricted to occurring in a certain location right outside the event horizon; you do not get a choice!
• And finally (and most importantly), she finds that there are no entanglements between radiation states emitted at significantly different times, something that you need if you're going to be a "pure state."

And so what these three papers, in tandem, have done, is demonstrate that there is no firewall and that the resolution to the firewall paradox is that the first assumption, that Hawking radiation is in a pure state, is the one that's flawed.




You won't read about this in the popular write-ups because it doesn't have a catchy headline, it's complex, and it's not work by someone that's already very famous for other work. But it's right. Hawking radiation is not in a pure state, and without that pure state, there's no firewall, and no paradox.
There is still an incredible amount to learn and understand about black holes, event horizons, and the behavior of quantum systems in strongly curved spacetime, to be sure, and there's lots of very interesting research ahead. These findings arguably raise more questions than they answer, although at least we know that black holes won't fry you when you fall in; it will still be death by spaghettification (http://en.wikipedia.org/wiki/Spaghettification), not by incineration!




And that's the actual end of the Black Hole Firewall Paradox!

---

* - A tremendous thanks to Sabine Hossenfelder (http://backreaction.blogspot.com/), author of this paper (http://arxiv.org/abs/1401.0288), for explaining many of her thoughts and many of the nuances of this topic to me. You can read her admonition of the outrageous Hawking claims here (http://backreaction.blogspot.com/2014/01/if-it-quacks-like-black-hole.html).

Izgleda da svakih nedelju dana or sou imamo nove uzbudljive priče o crnim rupama. Upoznajmo Plankove zvezde, novi tip zvezda koje nastaju iz crnih rupa. Strogo teoretski za sada, naravno:

New Type of Star Emerges From Inside Black Holes (https://medium.com/the-physics-arxiv-blog/6cf7ec0ed28b)

Quote
Born inside black holes, "Planck stars" could explain one of astrophysics' biggest mysteries and may already have been observed by orbiting gamma ray telescopes, say cosmologists
Black holes have fascinated scientists and the public alike for decades. There is special appeal in the idea that the universe contains regions of space so dense that light itself cannot escape and so extreme that the laws of physics no longer apply. What secrets can these extraordinary objects hide?
Today, we get an answer thanks to the work of Carlo Rovelli at the University of Toulon in France, and Francesca Vidotto at Radboud University in the Netherlands. These guys say that inside every black hole is the ghostly, quantum remains of the star from which it formed. And that these stars can later emerge as the black hole evaporates.
Rovelli and Vidotto call these objects "Planck stars" and say they could solve one of the most important questions in astrophysics. What's more, evidence for the existence of Planck stars may be readily available, simply by looking to the heavens.
Black holes arise naturally from Einstein's theory of general relativity which predicts that gravity influences the trajectory of photons moving through space. Indeed, when gravity is strong enough, light shouldn't be able to escape at all. That region is then a black hole.
Astrophysicists have long believed that black holes form when stars a little bigger than the Sun run out of fuel. No longer supported by thermal energy, the star collapses under its own weight to form a black hole. Since there is no known force that can stop this collapse, astrophysicists have always assumed that it eventually forms a singularity, a region of space that is infinitely dense.
But this has never been entirely satisfactory. The laws of physics break down in a region of infinite density, leaving physicists scratching their heads over what must be going on inside a black hole.
Even worse, many physicists believe black holes slowly evaporate and disappear. That raises problems because the information that describes an object must fully determine its future and be fully derivable from its past, at least in principle. But if black holes disappear, what happens to this information?
Nobody knows, a problem known as the "information paradox" and one of the hottest mysteries in astrophysics.
Now Rovelli and Vidotto have the answer. They begin by revisiting some ideas about what might happen should the universe end in a big crunch, the opposite of a big bang. Their key insight is that quantum gravitational effects prevent the universe from collapsing to infinite density. Instead, the universe "bounces" when the energy density of matter reaches the Planck scale, the smallest possible size in physics.
That's hugely significant. "The bounce does not happen when the universe is of planckian size, as was previously expected; it happens when the matter energy density reaches the Planck density," they say. In other words, quantum gravity could become relevant when the volume of the universe is some 75 orders of magnitude larger than the Planck volume.
Rovelli and Vidotto say the same reasoning can be applied to a black hole. Instead of forming a singularity, the collapse of a star is eventually stopped by the same quantum pressure, a force that is similar to the one that prevents an electron falling into the nucleus of an atom. "We call a star in this phase a "Planck star"," they say.
Planck stars would be small— stellar-mass black hole would form a Planck star about 10^-10 centimetres in diameter. But that's still some 30 orders of magnitude larger than the Planck length.
An interesting question is whether these Planck stars would be stable throughout the life of the black hole that surrounds them. Rovelli and Vidotto have a fascinating answer. They say that the lifetime of a Planck star is extremely short, about the length of time it takes for light to travel across it.
But to an outside observer, Planck stars would appear to exist much longer. That's because time slows down near high-density masses. For such an observer , a Planck star would last just as long as its parent black hole.
It then becomes possible for the black hole to interact with the Planck star it contains. Rovelli and Vidotto point out that as the black hole evaporates and shrinks, its boundary will eventually meet that of the Planck star as it expands after the bounce. "At this point there is no horizon any more and all information trapped inside can escape," they say.
That immediately solves the information paradox. The information isn't lost or trapped inside an unimaginably small region of space but eventually re-emitted into the universe.
There's yet another exciting consequence of these ideas. Rovelli and Vidotto say this release of information would generate radiation with a wavelength of about 10^-14 cm. In other words, gamma rays.
The universe is filled with a foggy background of gamma rays that astrophysicists have already observed in considerable detail with orbiting telescopes. Could it be that they have already detected the signature of Planck stars releasing their information into the cosmos?
There will certainly be no shortage of astrophysicists willing to comb through the data to find out. Worth watching in the near future.
Ref: http://arxiv.org/abs/1401.6562 (http://arxiv.org/abs/1401.6562) : Planck Stars

Daj nešto seksi. I to su crne rupe.

To ćemo na onom topiku sa fotografijama članova Sagite.

Do sada najstarija zvezda u univerzumu otkrivena:


ANU astronomers discover oldest star (http://news.anu.edu.au/2014/02/10/anu-team-discovers-oldest-star/)

Quote

A team led by astronomers at The Australian National University has discovered the oldest known star in the Universe, which formed shortly after the Big Bang 13.7 billion years ago.
The discovery has allowed astronomers for the first time to study the chemistry of the first stars, giving scientists a clearer idea of what the Universe was like in its infancy.
"This is the first time that we've been able to unambiguously say that we've found the chemical fingerprint of a first star," said lead researcher, Dr Stefan Keller of the ANU Research School of Astronomy and Astrophysics.
"This is one of the first steps in understanding what those first stars were like. What this star has enabled us to do is record the fingerprint of those first stars."
The star was discovered using the ANU SkyMapper telescope at the Siding Spring Observatory, which is searching for ancient stars as it conducts a five-year project to produce the first digital map the southern sky.
The ancient star is around 6,000 light years from Earth, which Dr Keller says is relatively close in astronomical terms. It is one of the 60 million stars photographed by SkyMapper in its first year.
"The stars we are finding number one in a million," says team member Professor Mike Bessell, who worked with Keller on the research.
"Finding such needles in a haystack is possible thanks to the ANU SkyMapper telescope that is unique in its ability to find stars with low iron from their colour."
Dr Keller and Professor Bessell confirmed the discovery using the Magellan telescope in Chile.
The composition of the newly discovered star shows it formed in the wake of a primordial star, which had a mass 60 times that of our Sun.
"To make a star like our Sun, you take the basic ingredients of hydrogen and helium from the Big Bang and add an enormous amount of iron – the equivalent of about 1,000 times the Earth's mass," Dr Keller says.
"To make this ancient star, you need no more than an Australia-sized asteroid of iron and lots of carbon. It's a very different recipe that tells us a lot about the nature of the first stars and how they died."
Dr Keller says it was previously thought that primordial stars died in extremely violent explosions which polluted huge volumes of space with iron. But the ancient star shows signs of pollution with lighter elements such as carbon and magnesium, and no sign of pollution with iron.
"This indicates the primordial star's supernova explosion was of surprisingly low energy. Although sufficient to disintegrate the primordial star, almost all of the heavy elements such as iron, were consumed by a black hole that formed at the heart of the explosion," he says.
The result may resolve a long-standing discrepancy between observations and predictions of the Big Bang.
The discovery was published in the latest edition of the journal Nature.

Naravno, moje poznavanje astronomije je ništavno pa sam ja duplo fasciniran da zvezda stara više od 13 milijardi godina (plus minus 6000 koliko treba da svetlo stigne do nas) i dalje postoji u formi zvezde, tj. da nije postala beli patuljak/ neutronska zvezda/ crna rupa ili koji bi već za njenu veličinu odgovarajući post-zvezdaški status bio. Zaključujem da je ovo jedna masivno-masivna zvezda sa MNOGO vodoničkog goriva, mada tekst zapravo govori prevashodno o gvožđu i ugljeniku.

Nisu baš snimci crnih rupa, ali je zanimljivo da je autor ovih fotografija profesionalni golfer koji je ove godine daleko najuspešniji - već je dobio par najjačih svetskih turnira...


http://jwalk.smugmug.com/ (http://jwalk.smugmug.com/)

Quote from: tomat on 19-09-2013, 00:08:57

QuoteIt could be time to bid the Big Bang bye-bye. Cosmologists have speculated that the Universe formed from the debris ejected when a four-dimensional star collapsed into a black hole — a scenario that would help to explain why the cosmos seems to be so uniform in all directions.

Nije za mene to bogznakakva novost. Davno sam čitao ono od Hokinga crne rupe i bebe vaseljene. Ili što moj buraz spekuliše o postojanju belih rupa u svom romanu...
Sa druge strane, gledao sam jednu pesimističku emisiju o sveopštem kraju kroz rasplinjavanje kosmosa, kad i crne rupe "ispare". Tamo je raspad crne rupe dat entropijski, nimalo kreativno kao "bljuvanje materije" ili nešto slično. Možda bi ga bolje opisao bljesak gama-zraka (fotona) koji će vremenom ići u crveni pomak, etc...
Međutim, iz mog ugla gledanja, zašto ne bi crna rupa rekonstruisala postojeće stanje, jer informacije su u njoj zadržane - tačnije na njoj, ako ćemo po hologramskoj teoriji.
Po hologramskoj teoriji možda nije bilo big banga, nego smo mi hologram nečega što je na udaljenoj površini (dve dimenzije) crne rupe.
Sa druge strane ne mislim da je "večna haotična inflacija" rekla sve svoje, a nju gotivim ne samo zbog toga što je "devedesetih" bilo sve kul  xrofl

Otkriveni gravitacioni talasi?

nejčer

http://www.nature.com/news/telescope-captures-view-of-gravitational-waves-1.14876 (http://www.nature.com/news/telescope-captures-view-of-gravitational-waves-1.14876)

b92

http://www.b92.net/zivot/nauka.php?yyyy=2014&mm=03&dd=17&nav_id=824989 (http://www.b92.net/zivot/nauka.php?yyyy=2014&mm=03&dd=17&nav_id=824989)

Big Bang's Smoking Gun Found (http://news.discovery.com/space/astronomy/big-bangs-smoking-gun-discovered-140317.htm)

Quote

For the first time, scientists have found direct evidence of the expansion of the universe, a previously theoretical event that took place a fraction of a second after the Big Bang explosion nearly 14 billion years ago.
      (https://www.znaksagite.com/diskusije/proxy.php?request=http%3A%2F%2Fstatic.ddmcdn.com%2Fen-us%2Fnews%2Fimg%2Fvideo-icon.png&hash=6c07f6aab848dfeb4afea79e650da68f21ad12f5)  The clue is encoded in the primordial cosmic microwave background radiation that continues to spread through space to this day.
Scientists found and measured a key polarization, or orientation, of the microwaves caused by gravitational waves, which are miniature ripples in the fabric of space.


Gravitational waves, proposed by Albert Einstein's General Theory of Relativity nearly 100 years ago but never before proven, are believed to have originated in the Big Bang explosion and then been amplified by the universe's inflation.
"This detection is cosmology's missing link," physicist Marc Kamionkowski, at Johns Hopkins University, told reporters during a webcast press conference on Monday.
"It's something that we thought should be there, but we weren't really sure. It has been eagerly sought now for close to two decades," he said.
Because gravitational waves squeeze space as they travel, they imprint a specific pattern in the cosmic microwave background. Like light waves, gravitational waves have "handedness" that correlates to left- and right-skewed polarizations.
ANALYSIS: Big Bang, Inflation, Gravitational Waves: What It Means (http://news.discovery.com/space/astronomy/big-bang-inflation-gravitational-waves-what-it-all-means-140317.htm)
Using a special telescope located at the South Pole, scientists not only detected gravitational waves in the universe's fossil radiation; they also found that the telltale polarization signals are much stronger than expected.
"This has been like looking for a needle in a haystack, but instead we found a crowbar," team co-leader Clem Pryke, with the University of Minnesota, said in a press release.
In addition to providing the first direct evidence of the universe's inflation, the measurements can be used to date the process and determine how much energy it took.
"This is not something that's just a home run, but a grand slam. It's the smoking gun for inflation. It hints at unification of the fundamental forces at energies 10 trillions of times higher than those accessible at the Large Hadron Collider at CERN," Kamionkowski said.


Computer models indicate that the universe expanded by 100 trillion trillion times in .0000000000000000000000000000000001 (10 to the minus-34) seconds after the Big Bang explosion 13.8 billion years ago.
The telescope used to detect the gravitational waves is called Bicep, short for Background Imaging of Cosmic Extragalactic Polarization.
"These results are as extraordinary as they get, and they will require the most extraordinary scrutiny," Kamionkowski said.
"If these results hold up ... then we've learned only that inflation has sent us a telegram, encoded on gravitational waves and transcribed on the cosmic microwave background sky. It will be essential in the years to come to follow through with more detailed and precise measurements to infer fully what this telegram is telling us," he added.

Занимљиво, брзина којом се Свемир раширио много пута превазилази брзину свјетлости. Али пошто свјетлости није било у том тренутку а и касније онда је ово логично.

Has The Hole in Stephen Hawking's Black Hole Theory Been Plugged?

[/size]
[/size]

Quote[/size]Earlier this year,[/size] [/size][color=rgb(0, 51, 153) !important]Stephen Hawking revised his theory of black holes (http://www.iflscience.com/physics/according-stephen-hawking-black-holes-we-currently-understand-them-do-not-exist)[/color][/size] [/size]to state that the "event horizon" which is a point of no return for everything—including light—cannot exist because it goes against everything that is known about information preservation in quantum physics. However, there were still some unresolved issues with Hawking's theory; issues which Chris Adami from Michigan State University claims to have resolved. The results of this study have been published in an open access format in the journal[/size] [/size][/color][color=rgb(0, 51, 153) !important]Classical and Quantum Gravity (http://iopscience.iop.org/0264-9381/31/7/075015/article)[/color][/size].[/size]Nearly 40 years ago, Hawking proposed a radiation that is emitted from black holes, now known as Hawking radiation. The radiation was believed to slowly evaporate the black hole and then disappear, effectively eliminating it and everything that has ever entered the black hole.
[/size]Unfortunately, this creates an information paradox and does not agree with any known law of physics. If this were true, it would mean that the Universe itself was fundamentally unpredictable. If it doesn't disappear, then where does the information go? Adami's groundbreaking new study incorporates all of Hawking's original calculations and combines them with what is now known about quantum systems.
[/size]The missing link, it seems, was the radiation's stimulated emission. This process was first described by Albert Einstein in 1917: when a photon hits an electron, the electron can be forced from the excited state down to the ground state and that energy difference manifests as another photon. Essentially, it works like a copy machine: one photon in, two photons out. This is the same principle that allows us to have Light Amplification by Stimulated Emission of Radiation; more commonly known as laser. Before light is drawn into the black hole, Adami determined, a copy is made that does not get destroyed. Thus, the information is preserved.
[/size]Though it will take some time for other scientists to check over the math and verify Adami's work, it has already received some support. Paul Davies, a theoretical physicist from Arizona State University agrees with the conclusion. "In my view Chris Adami has correctly identified the solution to the so-called black hole information paradox," Davies said in a press release. "Ironically, it has been hiding in plain sight for years. Hawking's famous black hole radiation is an example of so-called spontaneous emission of radiation, but it is only part of the story. There must also be the possibility of stimulated emission – the process that puts the S in LASER."
[/size]According to Adami: "Stephen Hawking's wonderful theory is now complete in my opinion. The hole in the black hole theory is plugged, and I can now sleep at night."

[/size]
[/size]http://www.iflscience.com/space/has-hole-stephen-hawking's-black-hole-theory-been-plugged

Most Convincing Evidence Yet For Dark Matter Detection

QuoteScientists have been analyzing high-energy gamma rays originating from the center of the Milky Way and have presented the most convincing case so far that at least some of this may come from dark matter.

Dark matter is a type of matter that is thought to account for apparent effects due to mass where no mass can be observed. It behaves differently to normal matter, such as planets and stars, which only accounts for approximately 5% of the universe. It neither emits nor absorbs light or other forms of electromagnetic energy, so a simple definition is that it is matter that does not react to light. The total mass-energy of the known universe is estimated to contain approximately 27% dark matter.

Using data collected from NASA's Fermi Gamma-ray Space Telescope, scientists from different institutions generated maps of the center of the galaxy. They found that some of the high-energy gamma rays could not be sufficiently explained by known sources. There are numerous known sources of gamma-rays in the center of the galaxy, such as supernova remnants, but it is also predicted to be rich in dark matter. Although scientists know dark matter exists, they are not entirely sure of what it is composed of. Weakly Interacting Massive Particles, or WIMPs, are a strong candidate. It is thought that collision of WIMPs may produce a quickly decaying particle, which could produce gamma rays detectable by Fermi.

Once they removed all the known sources of gamma rays from the Fermi observations, some emission was leftover. If dark matter particles with a particular mass are destroying each other, this would be a remarkable fit for the remaining emission. Despite this, the scientists err on the side of caution since alternative sources may still exist. Further sightings are also required to make this interpretation more convincing.

The Fermi scientists have also turned elsewhere in an attempt to detect dark matter by looking at dwarf galaxies orbiting the Milky Way. Dwarf galaxies are rich in dark matter and lack other types of gamma-ray sources present in the center of the Milky Way which make detection of dark matter problematic. On the flip side, their distance from us and the fact that the dark matter present is still considerably less than that in the center of the Milky Way means that the signals are weak. But according to Elliott Bloom, a member of the Fermi collaboration, "If we ultimately see a significant signal, it could be a very strong confirmation of the dark matter signal claimed in the galactic center."

While at this stage the signal cannot be confirmed or refuted as dark matter, it represents an exciting step towards the detection of dark matter at the galactic center.

http://www.iflscience.com/space/most-convincing-evidence-yet-dark-matter-detection (http://www.iflscience.com/space/most-convincing-evidence-yet-dark-matter-detection)

Zašto u univerzumu (dostupnom našoj opservaciji u ovom trenutku) preovlađuje materija umesto da imamo nekakav balans materije i antimaterije, kad je pretpostavka da su se obe kotirale podjednako dobro u post-big beng periodu? Ovo je jedno od pitanja koje muči fizičare već duže vreme. Medium ima lepu rekapitulaciju cele rasprave o bariogenezi:



Why are we made of matter? (https://medium.com/starts-with-a-bang/537d06075bae)

Ponovo medium.com:

Matematičko izvođenje dokaza da se univerzum potencijalno spontano formirao ni iz čega:
A Mathematical Proof That The Universe Could Have Formed Spontaneously From Nothing (https://medium.com/the-physics-arxiv-blog/ed7ed0f304a3)

I ponovo medium.com:


Ask Ethan #44: What came first, black holes or galaxies? (https://medium.com/starts-with-a-bang/ask-ethan-44-what-came-first-black-holes-or-galaxies-cef618a2f943)



Koliko možemo da vidimo, galaksije u svojim centrima imaju (super)masivne crne rupe. Pitanje je šta je bilo prvo - te crne rupe ili galaksije oko njih?

Jel' neko postavio teoriju mufova do sada?

Život, multiverzum i potencijal da se eksperimentalno potvrdi njegovo postojanje:


Will Science Burst the Multiverse's Bubble? (http://news.discovery.com/space/will-science-burst-the-multiverses-bubble-140718.htm)

Quote
Physicists aren't afraid of thinking big, but what happens when you think too big?
This philosophical question overlaps with real physics when hypothesizing what lies beyond the boundary of our observable universe. The problem with trying to apply science to something that may or may not exist beyond our physical realm is that it gets a little foggy as to how we could scientifically test it.
A leading hypothesis to come from cosmic inflation theory and advanced theoretical studies — centering around the superstring hypothesis — is that of the multiverse, an idea that scientists have had a hard time in testing.


In its most basic sense, the multiverse is a collection of universes popping in and out of existence, bustling around in a foamy mess, embedded in a vacuum of non-zero energy. Through quantum fluctuations, universes are born while others die — each universe taking on different forms and different kinds of physics.
But, if the multiverse hypothesis has any shred of reality behind it, how can scientists prove (or at least gather some observational evidence) that we exist inside one of an infinite ocean of universes?
This question is a tough one for scientists as many critics will argue that the multiverse hypothesis is nothing more than metaphysics, or a philosophical discussion. We are forever cocooned inside our universal 'bubble' and can therefore never experience what is going on 'outside' — if, indeed, there is an outside -- so what's the point in thinking about it?
But in a thought-provoking news release from the Perimeter Institute for Theoretical Physics, in Ontario, Canada (https://www.perimeterinstitute.ca/node/94107), theoretical physicists are working hard to marry the multiverse with observational science collected from the furthest-most frontiers of the Cosmos.


"We're trying to find out what the testable predictions of (the multiverse) would be, and then going out and looking for them," said Matthew Johnson of the Perimeter Institute for Theoretical Physics.
If the multiverse is real, it stands to reason that, in this rampaging mess of neighboring universal "bubbles," there should be frequent collisions, much like the jostling balls in a ball pit. Johnson's team has specifically set out to look for observational evidence of neighboring universes colliding with our own, thereby supplying some hint of observational evidence that we may have universal neighbors.
But to do this, Johnson must model the entire Universe.
"We start with a multiverse that has two bubbles in it, we collide the bubbles on a computer to figure out what happens, and then we stick a virtual observer in various places and ask what that observer would see from there," said Johnson.
"Simulating the universe is easy."


Although you have to admire his can-do attitude, the team aren't simulating every atom, star or galaxy in the Universe; in fact, the computer simulation only models the largest scale structures and forces. "All I need is gravity and the stuff that makes these bubbles up. We're now at the point where if you have a favorite model of the multiverse, I can stick it on a computer and tell you what you should see," he said.
This is where, according to the researchers, their work is so important if we are to understand what is going on in the regions beyond our Universe.
For example, if we consider a collision-filled multiverse, Jonson's model predicts that observations of the cosmic microwave background (CMB) radiation should exhibit rings, or 'bruises', where next-door universes are pushing against ours. The CMB is the ubiquitous (yet very faint) 'echo' of the Big Bang that can be seen at the most distant reaches of the Universe. If there's some interaction with universal bubbles (as some multiverse hypotheses suggest), these circular bruises should be present in the CMB signal – -representing distortions in the outermost edge of our 'bubble.'
Through a brief analysis of CMB maps of the entire sky, it appears that these circular rings are not present, potentially disproving a multiverse filled with colliding universes. Or it at least suggests the collisions aren't happening now — perhaps the multiverse is in some quiescent state?
As pointed out by the Institute press release, this research isn't setting out to prove whether or not the multiverse exists, it's merely identifying possible observational cues that we could look out for. And this pulls extra-universal studies into a scientific endeavor rather than leaving it in a metaphysical funk.

Putting The Multiverse To The Test (http://www.youtube.com/watch?v=w0uyR6JPkz4#ws)

Crne rupe, heh, ne postoje... tvrdi ovo istraživanje:



Researcher shows that black holes do not exist (http://phys.org/news/2014-09-black-holes.html)

Quote
Black holes have long captured the public imagination and been the subject of popular culture, from Star Trek to Hollywood. They are the ultimate unknown – the blackest and most dense objects in the universe that do not even let light escape. And as if they weren't bizarre enough to begin with, now add this to the mix: they don't exist.


By merging two seemingly conflicting theories, Laura Mersini-Houghton, a physics professor at UNC-Chapel Hill in the College of Arts and Sciences, has proven, mathematically, that black holes can never come into being in the first place. The work not only forces scientists to reimagine the fabric of space-time, but also rethink the origins of the universe.

"I'm still not over the shock," said Mersini-Houghton. "We've been studying this problem for a more than 50 years and this solution gives us a lot to think about."

For decades, black holes were thought to form when a massive star collapses under its own gravity to a single point in space – imagine the Earth being squished into a ball the size of a peanut – called a singularity. So the story went, an invisible membrane known as the event horizon surrounds the singularity and crossing this horizon means that you could never cross back. It's the point where a black hole's gravitational pull is so strong that nothing can escape it.

The reason black holes are so bizarre is that it pits two fundamental theories of the universe against each other. Einstein's theory of gravity predicts the formation of black holes but a fundamental law of quantum theory states that no information from the universe can ever disappear. Efforts to combine these two theories lead to mathematical nonsense, and became known as the information loss paradox.

In 1974, Stephen Hawking used quantum mechanics to show that black holes emit radiation. Since then, scientists have detected fingerprints in the cosmos that are consistent with this radiation, identifying an ever-increasing list of the universe's black holes.

But now Mersini-Houghton describes an entirely new scenario. She and Hawking both agree that as a star collapses under its own gravity, it produces Hawking radiation. However, in her new work, Mersini-Houghton shows that by giving off this radiation, the star also sheds mass. So much so that as it shrinks it no longer has the density to become a black hole.

Before a black hole can form, the dying star swells one last time and then explodes. A singularity never forms and neither does an event horizon. The take home message of her work is clear: there is no such thing as a black hole.

The paper, which was recently submitted to ArXiv, an online repository of physics papers that is not peer-reviewed, offers exact numerical solutions to this problem and was done in collaboration with Harald Peiffer, an expert on numerical relativity at the University of Toronto. An earlier paper, by Mersini-Houghton, originally submitted to ArXiv in June, was published in the journal Physics Letters B, and offers approximate solutions to the problem.

Experimental evidence may one day provide physical proof as to whether or not black holes exist in the universe. But for now, Mersini-Houghton says the mathematics are conclusive.

Many physicists and astronomers believe that our universe originated from a singularity that began expanding with the Big Bang. However, if singularities do not exist, then physicists have to rethink their ideas of the Big Bang and whether it ever happened.

"Physicists have been trying to merge these two theories – Einstein's theory of gravity and quantum mechanics – for decades, but this scenario brings these two theories together, into harmony," said Mersini-Houghton. "And that's a big deal."

http://arxiv.org/abs/1409.1837 (http://arxiv.org/abs/1409.1837)

Ako sam dobro razumeo oni zaključuju da nijedna crna rupa nije 100% crna, nego samo 99.999%, to jest da neka svetlost može da pobegne.

Edit: nisam dobro razumeo. Oni zaključuju da crna rupa ne može da se formira jer dok se zvezda sabija ona emituje Hokingovu radijaciju u tolikoj meri da izgubi masu potrebnu da se formira crna rupa. Zanimljivo.

Koliko JA iz ovoga mogu da razaberem, ne kažu ni to, nego kažu da zvezda kada kolabira pod gravitacionim pritiskom ne emituje samo radijaciju nego i masu i to do te mere da na kraju nema dovoljnu masu da kolabira u singularitet...

Većina planeta u kosmosu, tvrde, zapravo ne orbitira oko zvezde nego jurca unaokolo  :-? :-? :-? :-?


Throwback Thursday: Most Planets in the Universe are Homeless (https://medium.com/starts-with-a-bang/throwback-thursday-most-planets-in-the-universe-are-homeless-ad8cdce4d468)

A Mathematical Proof That The Universe Could Have Formed Spontaneously From Nothing (https://medium.com/the-physics-arxiv-blog/a-mathematical-proof-that-the-universe-could-have-formed-spontaneously-from-nothing-ed7ed0f304a3)

QuoteCosmologists assume that natural quantum fluctuations allowed the Big Bang to happen spontaneously. Now they have a mathematical proof

Ko ume da čita, ima i ceo rad ovde:


http://arxiv.org/pdf/1404.1207v1.pdf (http://arxiv.org/pdf/1404.1207v1.pdf)

Takođe:


'Revolutionary' New View of Baby Planets Forming Around a Star (http://news.discovery.com/space/astronomy/revolutionary-new-view-of-baby-planets-forming-around-a-star-141106.htm)

Quote
Welcome to HL Tauri — a star system that is just being born and the target of one of the most mind-blowing astronomical observations ever made.
Observed by the powerful Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, this is the most detailed view of the proto-planetary disk surrounding a young star 450 light-years away. And those concentric rings cutting through the glowing gas and dust? Those, my friends, are tracks etched out by planets being spawned inside the disk.
PHOTOS: Monster Desert Telescope Construction Complete (http://news.discovery.com/space/astronomy/alma-antenna-mega-telescope-pictures-131002.htm)
In short, this is the mother of all embryonic star system ultrasounds. But this dazzling new observation is so much more — it's a portal into our solar system's past, showing us what our system of planets around a young sun may have looked like over 4 billion years ago. And this is awesome, because it proves that our theoretical understanding about the evolution of planetary systems is correct.
However, there are some surprises.
"These features are almost certainly the result of young planet-like bodies that are being formed in the disc. This is surprising since such young stars are not expected to have large planetary bodies capable of producing the structures we see in this image," said Stuartt Corder, ALMA Deputy Director.
NEWS: It's Always a Windy Day Around This Baby Star (http://news.discovery.com/space/astronomy/its-always-a-windy-day-around-this-baby-star-14092.htm)
"When we first saw this image we were astounded at the spectacular level of detail," said Catherine Vlahakis, ALMA Deputy Program Scientist. "HL Tauri is no more than a million years old, yet already its disc appears to be full of forming planets. This one image alone will revolutionize theories of planet formation."


After a star sparks to life from the gravitational collapse of a star-forming nebula, the leftover gas and dust will collect around the star, creating a disk. Conventional theory suggests that, over time, the disk cools and small particles begin to accrete, forming small pebbles, then asteroids, then planetesimals and, eventually, planets.
PHOTOS: ALMA: New Jewel of the Atacama Desert (http://news.discovery.com/space/astronomy/alma-radio-telescope-inauguration-130317.htm)
As these embryonic planetary bodies orbit the star, they clear a track in the remaining disk of dust, 'vacuuming' up the remaining debris with their increasing gravitational dominance, continuing to bulk up their mass.
And this is exactly what we are seeing here. HL Tauri has a protoplanetary disk that is being populated with planets carving out their individual orbital paths. Eventually, the majority of the dust in HL Tauri will be consumed by the growing population of asteroids and planets, maturing into a stable star system like ours. However, the star system seems to be growing up fast, a puzzle that astronomers will no doubt be trying to understand for some time to come.
ALMA is nearing completion and this is the first precision observation in it's near-fully commissioned configuration. Using the technique of long-baseline interferometry, ALMA is composed of many individual antennae spread over a large area. The distance between the antennae mimics one large antenna spread over a huge area. ALMA can therefore beat the precision of any other observatory on Earth or even in space, including Hubble.
PHOTOS: The Most Mind-Blowing Space Spirals (http://news.discovery.com/space/most-mind-blowing-space-spirals-121019.htm)
"The logistics and infrastructure required to place antennas at such distant locations required an unprecedented coordinated effort by an expert international team of engineers and scientists," said ALMA Director Pierre Cox. "These long baselines fulfill one of ALMA's major objectives and mark an impressive technological, scientific and engineering milestone."
"Most of what we know about planet formation today is based on theory," added Tim de Zeeuw, Director General of the European Southern Observatory. "Images with this level of detail have up to now been relegated to computer simulations or artist's impressions. This high resolution image of HL Tauri demonstrates what ALMA can achieve when it operates in its largest configuration and starts a new era in our exploration of the formation of stars and planets."

vole Kinezi te komunističke naslove

Complex life may be possible in only 10% of all galaxies (http://news.sciencemag.org/physics/2014/11/complex-life-may-be-possible-only-10-all-galaxies)

QuoteThe universe may be a lonelier place than previously thought. Of the estimated 100 billion galaxies in the observable universe, only one in 10 can support complex life like that on Earth, a pair of astrophysicists argues. Everywhere else, stellar explosions known as gamma ray bursts would regularly wipe out any life forms more elaborate than microbes. The detonations also kept the universe lifeless for billions of years after the big bang, the researchers say.
"It's kind of surprising that we can have life only in 10% of galaxies and only after 5 billion years," says Brian Thomas, a physicist at Washburn University in Topeka who was not involved in the work. But "my overall impression is that they are probably right" within the uncertainties in a key parameter in the analysis.
Scientists have long mused over whether a gamma ray burst could harm Earth. The bursts were discovered in 1967 by satellites designed to spot nuclear weapons tests and now turn up at a rate of about one a day. They come in two types. Short gamma ray bursts last less than a second or two; they most likely occur when two neutron stars or black holes spiral into each other. Long gamma ray bursts last for tens of seconds and occur when massive stars burn out, collapse, and explode. They are rarer than the short ones but release roughly 100 times as much energy. A long burst can outshine the rest of the universe in gamma rays, which are highly energetic photons.
That seconds-long flash of radiation itself wouldn't blast away life on a nearby planet. Rather, if the explosion were close enough, the gamma rays would set off a chain of chemical reactions that would destroy the ozone layer in a planet's atmosphere. With that protective gas gone, deadly ultraviolet radiation from a planet's sun would rain down for months or years—long enough to cause a mass die-off.
How likely is that to happen? Tsvi Piran, a theoretical astrophysicist at the Hebrew University of Jerusalem, and Raul Jimenez, a theoretical astrophysicist at the University of Barcelona in Spain, explore that apocalyptic scenario in a paper in press at Physical Review Letters (http://arxiv.org/abs/1409.2506).
Astrophysicists once thought gamma ray bursts would be most common in regions of galaxies where stars are forming rapidly from gas clouds. But recent data show that the picture is more complex: Long bursts occur mainly in star-forming regions with relatively low levels of elements heavier than hydrogen and helium—low in "metallicity," in astronomers' jargon.
Using the average metallicity and the rough distribution of stars in our Milky Way galaxy, Piran and Jimenez estimate the rates for long and short bursts across the galaxy. They find that the more-energetic long bursts are the real killers and that the chance Earth has been exposed to a lethal blast in the past billion years is about 50%. Some astrophysicists have suggested a gamma ray burst may have caused the Ordovician extinction, a global cataclysm about 450 million years ago that wiped out 80% of Earth's species, Piran notes.
The researchers then estimate how badly a planet would get fried in different parts of the galaxy. The sheer density of stars in the middle of the galaxy ensures that planets within about 6500 light-years of the galactic center have a greater than 95% chance of having suffered a lethal gamma ray blast in the last billion years, they find. Generally, they conclude, life is possible only in the outer regions of large galaxies. (Our own solar system is about 27,000 light-years from the center.)
Things are even bleaker in other galaxies, the researchers report. Compared with the Milky Way, most galaxies are small and low in metallicity. As a result, 90% of them should have too many long gamma ray bursts to sustain life, they argue. What's more, for about 5 billion years after the big bang, all galaxies were like that, so long gamma ray bursts would have made life impossible anywhere.
But are 90% of the galaxies barren? That may be going too far, Thomas says. The radiation exposures Piran and Jimenez talk about would do great damage, but they likely wouldn't snuff out every microbe, he contends. "Completely wiping out life?" he says. "Maybe not." But Piran says the real issue is the existence of life with the potential for intelligence. "It's almost certain that bacteria and lower forms of life could survive such an event," he acknowledges. "But [for more complex life] it would be like hitting a reset button. You'd have to start over from scratch."
The analysis could have practical implications for the search for life on other planets, Piran says. For decades, scientists with the SETI Institute in Mountain View, California, have used radio telescopes to search for signals from intelligent life on planets around distant stars. But SETI researchers are looking mostly toward the center of the Milky Way, where the stars are more abundant, Piran says. That's precisely where gamma ray bursts may make intelligent life impossible, he says: "We are saying maybe you should look in the exact opposite direction."

The Multiverse and you (https://medium.com/starts-with-a-bang/ask-ethan-73-the-multiverse-and-you-46c9e3c493e2): Is there another version of you somewhere out there in a parallel Universe? (https://medium.com/starts-with-a-bang/ask-ethan-73-the-multiverse-and-you-46c9e3c493e2)

Zgodan tekst da se shvati kako to nije za fantastičarski pristup multiverzumu (multiverzumima?). Smem da se kladim da niko sa ZS, uključujući i sve njihove verzije u multiverzumima nije u stanju da linkovan tekst pročita, a kamoli da razume. Ono šta je bitno za ovaj forum jeste da je literarni deo teorije multiverzuma nastao kao posledica potrebe da se oslobodi prostor za prevazilaženje vremenskog paradoksa. A vremenski paradoks je posledica SF igrarija sa putovanjem kroz vreme, koje se na sličan, naučni način, da obrazložiti kao moguć događaj. Neko će reći da vremenski paradoks egzistira samo u delu putovanja kroz vreme u prošlost, ali, ako se promene u budućnosti mogu posmatrati i kao sadašnjost neke druge stvarnosti, onda paradoks i dalje postoji i varijanta multiverzuma je zgodno rešenje da se prevaziđe. 
Ja sve teorije o multiverzumima shvatam kao stepen slobode naučnoj fantastici da ne bude viđena kao gola fantazija. Bez obzira da li se grade na teoriji struna, zakrivljenom prostoru ili kvantnom titraju univerzuma u kome postoji naša verzija ličnosti, važno je samo da priče u tom tkanju budu uverljive i moguće samo u tom izmenjenom svetu. Sve ostalo je banalizacija i traćenje.

A sad ovo:

No Big Bang? Quantum equation predicts universe has no beginning (http://phys.org/news/2015-02-big-quantum-equation-universe.html)

Quote
(Phys.org) —The universe may have existed forever, according to a new model that applies quantum correction terms to complement Einstein's theory of general relativity. The model may also account for dark matter and dark energy, resolving multiple problems at once.
The widely accepted age of the universe, as estimated by general relativity, is 13.8 billion years. In the beginning, everything in existence is thought to have occupied a single infinitely dense point, or singularity. Only after this point began to expand in a "Big Bang" did the universe officially begin.
Although the Big Bang singularity arises directly and unavoidably from the mathematics of general relativity, some scientists see it as problematic because the math can explain only what happened immediately after—not at or before—the singularity.
"The Big Bang singularity is the most serious problem of general relativity because the laws of physics appear to break down there," Ahmed Farag Ali at Benha University and the Zewail City of Science and Technology, both in Egypt, told Phys.org.
Ali and coauthor Saurya Das at the University of Lethbridge in Alberta, Canada, have shown in a paper published in Physics Letters B that the Big Bang singularity can be resolved by their new model in which the universe has no beginning and no end.
Old ideas revisited
The physicists emphasize that their quantum correction terms are not applied ad hoc in an attempt to specifically eliminate the Big Bang singularity. Their work is based on ideas by the theoretical physicist David Bohm, who is also known for his contributions to the philosophy of physics. Starting in the 1950s, Bohm explored replacing classical geodesics (the shortest path between two points on a curved surface) with quantum trajectories.
In their paper, Ali and Das applied these Bohmian trajectories to an equation developed in the 1950s by physicist Amal Kumar Raychaudhuri at Presidency University in Kolkata, India. Raychaudhuri was also Das's teacher when he was an undergraduate student of that institution in the '90s.

Using the quantum-corrected Raychaudhuri equation, Ali and Das derived quantum-corrected Friedmann equations, which describe the expansion and evolution of universe (including the Big Bang) within the context of general relativity. Although it's not a true theory of quantum gravity, the model does contain elements from both quantum theory and general relativity. Ali and Das also expect their results to hold even if and when a full theory of quantum gravity is formulated.
No singularities nor dark stuff
In addition to not predicting a Big Bang singularity, the new model does not predict a "big crunch" singularity, either. In general relativity, one possible fate of the universe is that it starts to shrink until it collapses in on itself in a big crunch and becomes an infinitely dense point once again.
Ali and Das explain in their paper that their model avoids singularities because of a key difference between classical geodesics and Bohmian trajectories. Classical geodesics eventually cross each other, and the points at which they converge are singularities. In contrast, Bohmian trajectories never cross each other, so singularities do not appear in the equations.
In cosmological terms, the scientists explain that the quantum corrections can be thought of as a cosmological constant term (without the need for dark energy) and a radiation term. These terms keep the universe at a finite size, and therefore give it an infinite age. The terms also make predictions that agree closely with current observations of the cosmological constant and density of the universe.
New gravity particle
In physical terms, the model describes the universe as being filled with a quantum fluid. The scientists propose that this fluid might be composed of gravitons—hypothetical massless particles that mediate the force of gravity. If they exist, gravitons are thought to play a key role in a theory of quantum gravity.
In a related paper, Das and another collaborator, Rajat Bhaduri of McMaster University, Canada, have lent further credence to this model. They show that gravitons can form a Bose-Einstein condensate (named after Einstein and another Indian physicist, Satyendranath Bose) at temperatures that were present in the universe at all epochs.
Motivated by the model's potential to resolve the Big Bang singularity and account for dark matter and dark energy, the physicists plan to analyze their model more rigorously in the future. Their future work includes redoing their study while taking into account small inhomogeneous and anisotropic perturbations, but they do not expect small perturbations to significantly affect the results.
"It is satisfying to note that such straightforward corrections can potentially resolve so many issues at once," Das said.
Explore further: Did the universe originate from a hyper-dimensional black hole?
More information: Ahmed Farag Ali and Saurya Das. "Cosmology from quantum potential." Physics Letters B. Volume 741, 4 February 2015, Pages 276–279. DOI: 10.1016/j.physletb.2014.12.057. Also at: arXiv:1404.3093[gr-qc].
Saurya Das and Rajat K. Bhaduri, "Dark matter and dark energy from Bose-Einstein condensate", preprint: arXiv:1411.0753[gr-qc].
Journal reference: Physics Letters B search and more info website

ко год да је кренуо бомовим стопама завршио је сучељен са уобичајеном интерпретацијом универзума

How The Nature of Information Could Resolve One of The Great Paradoxes Of Cosmology (https://medium.com/the-physics-arxiv-blog/how-the-nature-of-information-could-resolve-one-of-the-great-paradoxes-of-cosmology-8c16fc714756)

Monster black hole born shortly after big bang (http://www.znaksagite.com/diskusije/news.sciencemag.org/space/2015/02/monster-black-hole-born-shortly-after-big-bang)

Quote
All galaxies are thought to have supermassive black holes at their center. These start out small—with masses equivalent to between 100 and 100,000 suns—and build up over time by consuming the gas, dust, and stars around them or by merging with other black holes to reach sizes measured in millions or billions of solar masses. Such binge eating usually takes billions of years, but a team of astronomers was stunned to discover what is, in galactic terms, a monstrous baby: a gigantic black hole of 12 billion solar masses in a barely newborn galaxy, just 875 million years after the big bang. The researchers report online in Nature today that they were scouring through several astronomical surveys looking for bright objects in the very early universe called quasars, galaxies that burn very bright because their central black holes are consuming material so fast. The monster they found (http://dx.doi.org/10.1038/nature14241) (depicted in this artist's impression) is roughly 3000 times the size of our Milky Way's central black hole. To have grown to such a size in so short a time, it must have been munching matter at close to the maximum physically possible rate for most of its existence. Its large size and rate of consumption also makes it the brightest object in that distant era, and astronomers can use its bright light to study the composition of the early universe: how much of the original hydrogen and helium from the big bang had been forged into heavier elements in the furnaces of stars.

Universe may be on the brink of collapse (on the cosmological timescale) (http://phys.org/news/2015-03-universe-brink-collapse-cosmological-timescale.html?utm_source=nwletter&utm_medium=email&utm_content=splt-item&utm_campaign=daily-nwletter)

Quote
(Phys.org)—Physicists have proposed a mechanism for "cosmological collapse" that predicts that the universe will soon stop expanding and collapse in on itself, obliterating all matter as we know it. Their calculations suggest that the collapse is "imminent"—on the order of a few tens of billions of years or so—which may not keep most people up at night, but for the physicists it's still much too soon.

In a paper published in Physical Review Letters, physicists Nemanja Kaloper at the University of California, Davis; and Antonio Padilla at the University of Nottingham have proposed the cosmological collapse mechanism and analyzed its implications, which include an explanation of dark energy.
"The fact that we are seeing dark energy now could be taken as an indication of impending doom, and we are trying to look at the data to put some figures on the end date," Padilla told Phys.org. "Early indications suggest the collapse will kick in in a few tens of billions of years, but we have yet to properly verify this."
The main point of the paper is not so much when exactly the universe will end, but that the mechanism may help resolve some of the unanswered questions in physics. In particular, why is the universe expanding at an accelerating rate, and what is the dark energy causing this acceleration? These questions are related to the cosmological constant problem, which is that the predicted vacuum energy density of the universe causing the expansion is much larger than what is observed.
"I think we have opened up a brand new approach to what some have described as 'the mother of all physics problems,' namely the cosmological constant problem," Padilla said. "It's way too early to say if it will stand the test of time, but so far it has stood up to scrutiny, and it does seem to address the issue of vacuum energy contributions from the standard model, and how they gravitate."
The collapse mechanism builds on the physicists' previous research on vacuum energy sequestering, which they proposed to address the cosmological constant problem. The dynamics of vacuum energy sequestering predict that the universe will collapse, but don't provide a specific mechanism for how collapse will occur.
According to the new mechanism, the universe originated under a set of specific initial conditions so that it naturally evolved to its present state of acceleration and will continue on a path toward collapse. In this scenario, once the collapse trigger begins to dominate, it does so in a period of "slow roll" that brings about the accelerated expansion we see today. Eventually the universe will stop expanding and reach a turnaround point at which it begins to shrink, culminating in a "big crunch."

Currently, we are in the period of accelerated expansion, and we know that the universe is approximately 13.8 billion years old. So in order for the new mechanism to work, the period of accelerated expansion must last until at least this time (needless to say, a mechanism that predicts that the universe has already collapsed is obviously flawed). The collapse time can be delayed by choosing an appropriate slope, which in this case, is a slope that has a very tiny positive value—about 10-39 in the scientists' equation. The very gradual slope means that the universe evolves very slowly.
Importantly, the scientists did not choose a slope just to fit the observed expansion and support their mechanism. Instead, they explain that the slope is "technically natural," and takes on this value due to a symmetry in the theory.
As the physicists explain, the naturalness of the mechanism makes it one of the first ever models that predicts acceleration without any direct fine-tuning. In the mechanism, the slope alone controls the universe's evolution, including the scale of the accelerated expansion.
"The 'technically natural' size of the slope controls when the collapse trigger begins to dominate, but was it guaranteed to give us slow roll and therefore the accelerated expansion?" Padilla said. "Naively one might have expected to have to fine-tune some initial conditions to guarantee this, but remarkably that is not the case. The dynamics of vacuum energy sequestering guarantee the slow roll."
The idea is still in its early stages, and the physicists hope to build on it much more in the future.
"There is much to do," Padilla said. "Right now we are working on a way to describe our theory in a way that is manifestly local, which will make it more conventional, and more obviously in keeping with some of the key principles behind quantum theory (namely, linear superposition). We would also like to devise more tests of the idea, both cosmological and astrophysical.
"Over the longer term, we would like to understand how our theory could emerge from a more fundamental theory, such as string theory. It is also important to ask what happens when we consider vacuum energy corrections from quantum gravity."
If there was ever a justification that more work is needed, it may be in the paper's conclusion:
"The present epoch of acceleration may be evidence of impending doom. . . A detailed analysis to better quantify these predictions is certainly warranted."

(Phys.org)—Physicists have proposed a mechanism for "cosmological collapse" that predicts that the universe will soon stop expanding and collapse in on itself, obliterating all matter as we know it. Their calculations suggest that the collapse is "imminent"—on the order of a few tens of billions of years or so—which may not keep most people up at night, but for the physicists it's still much too soon.

Read more at: http://phys.org/news/2015-03-universe-brink-collapse-cosmological-timescale.html#jCp (http://phys.org/news/2015-03-universe-brink-collapse-cosmological-timescale.html#jCp)

Moguće je da supermasivna crna rupa u centru mlečnog puta fasilitira stvaranje novih zvezda:

Stars May Form in Shadow of Galaxy's Black Hole Beast (http://news.discovery.com/space/galaxies/stars-may-form-in-shadow-of-galaxys-black-hole-beast-150410.htm)

Quote
Despite the harsh environment created by the monster black hole lurking in the center of the Milky Way galaxy, new observations show that stars — and, potentially, planets — are forming just two light-years away from the colossal giant.

Bright and massive stars were spotted circling (http://www.space.com/5755-stars-form-black-hole-chaos.html) the 4-million-solar-mass behemoth more than a decade ago, sparking a debate within the astronomy community. Did they migrate inward after they formed? Or did they somehow manage to form in their original positions?

ANALYSIS: Rare 'Medium-Sized' Black Hole Creates Galactic Dead Zone (http://news.discovery.com/space/astronomy/rare-medium-sized-black-hole-creates-galactic-dead-zone-150226.htm)

Most astronomers had said the latter idea seemed far-fetched, given that the black hole wreaks havoc on its surroundings, often stretching any nearby gas into taffylike streamers before it has a chance to collapse into stars. But the new study details observations of low-mass stars forming within reach of the galactic center. The findings lend support to the argument that "adult" stars observed in this region formed near the black hole. [Images: Milky Way's Monster Black Hole Shreds Space Cloud (http://www.space.com/21992-gas-cloud-ripped-black-hole-images.html)]

The new evidence for ongoing star formation near the black hole is "a nail in the coffin" for the theory that the stars form in situ, said lead author Farhad Yusef-Zadeh, of Northwestern University. The observations, if accurate, make it unlikely that the stars migrated from elsewhere, the researchers said.

Birth Near a Black Hole

Stars are born (http://www.space.com/10373-star-born-gas-clouds-stellar-fusion.html) within clouds of dust and gas. Turbulence within these clouds give rise to knots that begin to collapse under their own weight. The knots grows hotter and denser, rapidly becoming protostars, which are so-named because they have yet to start fusing hydrogen into helium.

ANALYSIS: Why Our Galaxy's Black Hole Didn't Eat Mystery Object (http://news.discovery.com/space/astronomy/why-our-galaxys-black-hole-didnt-eat-that-mystery-object-141104.htm)

But a protostar can rarely be seen. It has yet to generate energy via nuclear fusion, and any faint light it does produce is often blocked by the disk of gas and dust still surrounding it.

So, when Yusef-Zadeh and his colleagues used the Very Large Array in New Mexico to scan the skies near the central supermassive black hole, they didn't spot the protostars but rather the disks of gas and dust surrounding them.

"You could see these beautiful cometary-shaped structures," Yusef-Zadeh told Space.com. Intense starlight and stellar winds from previously discovered high-mass stars had shaped these disks into cometlike structures with bright heads and tails. Similar structures (called bow shocks) can be seen anywhere young stars are being born, including the famous Orion Nebula (http://www.space.com/14034-gallery-amazing-orion-nebula-photos.html).

ANALYSIS: Our Galaxy's Black Hole Does NOT Have the 'Munchies' (http://news.discovery.com/space/galaxies/our-galaxys-black-hole-does-not-have-the-munchies-140721.htm)

"There is, of course, one big catch here — and that is that the tidal force on the black hole is so strong that it's hard to see how these stars would form," Yusef-Zadeh said. "Many people think that star formation is forbidden near a supermassive black hole. But nature finds a way."

Astronomers have managed to find a way as well. Over the last decade, they've come up with two scenarios, both of which use the nearby black hole to simulate star formation.

Kad ste već tu, pogledajte i ovaj video koji objašnjava argumente za postojanje velikog praska, nove i uverljive:


http://news.discovery.com/space/galaxies/how-we-know-the-big-bang-actually-happened-video.htm (http://news.discovery.com/space/galaxies/how-we-know-the-big-bang-actually-happened-video.htm)

Where did light first come from? (https://medium.com/starts-with-a-bang/ask-ethan-84-where-did-light-first-come-from-e6054566ea74)

Wormholes Untangle a Black Hole Paradox (https://www.quantamagazine.org/20150424-wormholes-entanglement-firewalls-er-epr/)

Što se mene tiče, ovo je moglo da bude napisano i na kineskom, sve bih isto razumeo kao i sada  :lol:

Ali interesantno je.

Bog možda zaista ne baca kockice, ali se sa galaksijama prilično zajebava:

Tiny and Speedy: 'Homeless' Galaxies Ejected From Clusters (http://news.discovery.com/space/astronomy/tiny-and-speedy-homeless-galaxies-ejected-from-clusters-150423.htm)

Quote
Like stars that can be ejected from galaxies, resigned to an eternity floating through the darkness of intergalactic space, astronomers have discovered entire galaxies — 11 in total — that underwent some unpleasant gravitational turbulence and flung from their home clusters, marooned in intercluster space.
"These galaxies are facing a lonely future, exiled from the galaxy clusters they used to live in," said Igor Chilingarian, an astronomer at the Harvard-Smithsonian Center for Astrophysics and Moscow State University.
ANALYSIS: 'Missing' Evolutionary Link for Compact Galaxies Found (http://news.discovery.com/space/astronomy/mystery-evolutionary-link-for-compact-galaxies-revealed-140106.htm)
Runaway stars can be ejected from their host galaxies if they are travelling at a greater speed than that galaxy's "escape velocity." Like a rocket leaving Earth's gravitational well, escape velocity can only be achieved if the rocket is supplied with enough energy to exceed 11.2 kilometers per second (25,000 miles per hour). In the case of a star being ejected from our galaxy, it would need to be traveling a speed of 537 km/s (over 1.2 million miles per hour!).
So you can probably imagine the astronomical speed an entire galaxy would need to travel to leave the gravitational heft of an entire galaxy cluster — a velocity of up to 3,000 km/s (6 million miles per hour), depending on the mass of the cluster.
The 11 runaway galaxies were found by chance while Chilingarian and co-investigator Ivan Zolotukhin, of the L'Institut de Recherche en Astrophysique et Planetologie and Moscow State University, were scouring publicly-available data (via the Virtual Observatory (http://www.virtualobservatory.org/)) from the Sloan Digital Sky Survey and the GALEX satellite for compact elliptical galaxies.
ANALYSIS: The Grown-Up Galaxy Among Kids (http://news.discovery.com/space/astronomy/the-grown-up-galaxy-among-kids.htm)
These tiny galaxies are rare, but the researchers were able to uncover 200 previously unknown compact ellipticals, 11 of which were found to be alone and separated from any galactic cluster. And they are moving really, really fast.
"The first compact ellipticals were all found in clusters because that's where people were looking. We broadened our search, and found the unexpected," said Zolotukhin. Elliptical galaxies are thought to originate from larger galaxies that go through gravitational interactions with neighboring galaxies; ellipticals are therefore expected to be clustered near larger 'parent' galaxies.
So how did these tiny galaxies, which are approximately 1,000 times smaller than our galaxy, end up so far away from home?
The researchers think that a similar gravitational mechanism that produces runaway stars may be also slingshotting these ellipticals.
"We asked ourselves, what else could explain them? The answer was a classic three-body interaction," said Chilingarian.
NEWS: Weird Little Galaxy Hides a Giant Black Hole (http://news.discovery.com/space/astronomy/weird-little-galaxy-has-a-giant-black-hole-140917.htm)
One way a hypervelocity star can be produced is if one star in a binary pair strays too close to a black hole. When the star gets swallowed, its binary partner is flung away. In the case of a hypervelocity compact elliptical galaxy, should a massive galaxy collide with the elliptical's parent galaxy, the elliptical could be flung away as the two larger galaxies merge.
For the compact elliptical galaxy, this galactic merger is the start of its long and, potentially, infinite journey into the cosmic abyss.

e,mene ti naucnici zaaaaista zasmejavaju....CRNE RUPE!?!?
ma sve njihove teorije vrede kolko i ono sto izadje iz moje 'crne rupe'....

pobrkali su oni odavno nauku i fantastiku....

Ne veruješ da postoje crne rupe? Ali teorija iza njih i dokazi su više nego solidni. Za širenje našeg celokupnog znanja nije previše bitno što baš ti ne veruješ u crne rupe, ali me zanima otkud to? U šta tačno ne veruješ u vezi sa crnim rupama?

dokazi? kakvi dokazi? nekoliko zatamnjenih pixela iz navodnih opservatorija? i par naucnika koji tapsu jedni druge po ramenu...

Jebiga, sad ja treba da potrošim ceo sat za objašnjenje, da bi se na kraju ispostavilo da samo troluješ. Nije to u redu. Evo ti objašnjenje (https://briankoberlein.com/2014/09/25/yes-virginia-black-holes/) s linkovima. Za tebe je samo prvi pasus u članku, s obiljem linkova, a posle toga se opovrgava neka friška nova teorija koja kaže da crne rupe matematički ne mogu da postoje, što ovom trenutku nije predmet rasprave, pa bolje ignoriši.

Ali pre nego što stignemo do crnih rupa, da te pitam, veruješ li u Ajnštajnovu opštu teoriju relativiteta? To je nešto u fizici takođe neosporno (za sada). Ono što hoću da kažem je da je nemoguće verovati u jedno, a ne i u drugo. Druga stvar, šta ti znaš o crnim rupama? Jesu li to za tebe samo dve reči, ili imaš neko znanje?

Nemoguće je ne verovati u Ajnštajnovu teoriju, jer su potvrde za njeno postojanje nebrojene. Geostacionarni sateliti ne bi mogli da rade da njhovi časovnici nisu nešto malo sporiji od svih časovnika na Zemlji, a moraju da budu sporiji da bi bili sinhronizovani sa časovnicima na Zemlji, jer se nalaze u slabijem gravitacionom polju. Baš kao što Ajnštajnova teorija kaže, vreme drugačije teče u različitim gravitacionim poljima.

Masivne zvezde iskrivljuju svetlost koja prolazi tik pored njih, super-masivne iskrivljuju još više, a kad ta super-masivnost pređe određenu granicu onda se svetlost iskrivljuje najviše. Jedna posledica Ajnštajnove teorije je da se svetlost koja napušta površinu tela sa kritično velikom gravitacijom nalazi u toliko usporenom vremenu da svetlosti treba praktično beskonačno vremena da napusti gravitaciono polje. Posledica je da tu svetlost (koja zaista postoji) mi nikad nećemo videti, i zato se objekat zove crna rupa. Svetlost postoji, ali mi je nikad nećemo videti.

Druga posledica teorije je da se u blizini masivnih objekata zraci svetlosti iskrivljuju. To vidimo već sada kad posmatramo zvezde na ivici Sunčevog diska. Zvezde se malo pomeraju (vrlo malo), što je u skladu sa idejom da se zraci svetlosti iskrivljuju. E pa, u blizini super-masivnih objekata zraci se toliko iskrivljuju da je moguće videti ono što je iza objekta. Moguće je videti nekoliko slika onoga što je iza objekta. Ako u svemiru vidimo tako nešto, više slika iste stvari, a ne vidimo centar, onda to što ne vidimo je po svemu sudeći crna rupa. Prosto nema šta drugo da bude.

Quote from: mac on 28-04-2015, 13:26:51
Ali pre nego što stignemo do crnih rupa, da te pitam, veruješ li u Ajnštajnovu opštu teoriju relativiteta?

ne znam koliko je to pitanje vere. može se možda dokazati da to ne radi, ali to nije stvar vere.

mac, brate, cujes li ti sebe?
uopste ne trolujem,ali moram da se ne slozim da treba 100% verovati svim tim bilmezima...
prvo:To je nešto u fizici takođe neosporno (za sada)....
e jebi ga ako ocekujes i sam da ga neko ospori, onda stvaaaaarno....

a to o casovnicima i gravitaciji?
pa napravljeni su ovde na zemlji a onda otisli negde gde nije zemlja, i trt....
gledao si film WALL-E.....sta se desi sa ljudima....?
prosto objasnjenje...


Svetlost postoji, ali mi je nikad nećemo videti.

....sve same teorije do teorije...ko ti kaze da je necemo videti...? i to je teorija, mozda hocemo...

Jedini cvrst dokaz koji ja mogu da ponudim u vezi svih njihovih teorija, je da nikakve konkretne vajde mi nemamo od svih tih teorija,i da su sve one vise fantastika nego nauka.

I naravno nisi posetio link, nisi pročitao, nisi posetio linkove koji su dati u članku, nego si odmah dao svoj komentar u kome ne veruješ, i tačka. Pa dobro, "ne veruj".

Quote from: Ugly MF on 28-04-2015, 13:39:41
... nikakve konkretne vajde mi nemamo od svih tih teorija,i da su sve one vise fantastika nego nauka...

Contributions of Physics to the Information Age (http://www.physics.ucla.edu/~ianb/history/)

jedno su teorije i istrazivanja ovde gde je sve to opipljivo i primenjljivo,nisam ja protiv fizike i ostalih pametnih nauka,nadam se da nigde nisam ni kuckao takvo sto,ali da verujem u tamo neke imaginacije...

Hm, da, ali gde je ta tačka gde imaginarno postaje realno? Kad igraš peek-a-boo sa malim detetom i pokriješ svoje lice, dete pomisli da si nestao, ali ti znaš da nisi. Zar ne bismo mogli kompetentnim naučnicima da dozvolimo da budu "roditelji", to jest da oni u ime cele civilizacije odvoje imaginarno od realnog? I to, sigurno ne jednom naučniku, nego celoj naučnoj javnosti. Cela naučna javnost je sigurno kompetentnija, i zna znanje. Mislim, za to su se ljudi školovali, i za to platu primaju.

Nego, jesi li ispratio link i pročitao članke? Daj da pričamo o konkretnom, a ne o verovanjima u imaginacije...

pa i crne rupe su valjda neka fizika. a teško da je kvantna mehanika "nešto opipljivo".

Rado bih se umešao, ali vam se ne bi dopalo. Teorije i hipoteze nisu ništa više od toga bez tvrdih dokaza. Što bi rekli pravnici, teorije o kojima raspravljate su na osnovu posrednih dokaza. Ako crne rupe ne priznaju, nema sudske odluke.

Ma ima dokaza, nego niko neće da klikće na linkove...

Neće. NI ja neću. Ti dokazi nisu pravi dokazi.

imaginarno je kad me ceo naucni svet ubedjuje u genijalnost nepokretnog coveka u kolicima koji prica kroz masinu, i kaze mi da ja treba da verujem da je on genijalan zato jer je suvise pametan za njih da bi ga sami razumeli....
pa mi onda isti ti naslazu gomile imaginarnih podataka o teorijama da je tamo nesto sto mi nikada necemo videti,ali oni su ubedjeni da je to tako jer su im i njihove kolege ptvrdile da su ubedjeni u mogucnost njihovih teorija!

mac, da li sada nakon gomile nakuckanih slova zvucim malko elokventnije?
(....ako nastavim da tupim na 15 strana,garant dobijam doktorat na faxu gde i nas precednik!....samo jos kad bi mi Toma reko de je taj faxultet...)

Nauka ne funkcioniše tako kako si sad opisao. Nije bitno koliko si nepokretan, i koliko je ko u šta ubeđen. Bitna je samo epirijska potvrda našeg modela prirode.

ali nije ni hawking bas neki primjer znanstvenog pristupa; od rada do rada se revidira. jednostavno postavlja zanimljive hipoteze i nagadja na visokoj razini. inace ga zovem hawkings, s = spekulation.

funkcionisanje i ubedjenost....
kakvu funkciju ja imam ako sam ubedjen da je ovaj nas svet isprdjen iz nekog supka i to nazvano BIGBANG....pre nekoliko milijardi godina...?
verovatno da se naprzim na trabunjanja i kupujem njihove knjige....
neka fala, vise volim postene frenk herberte sa dinama i asimove sa zaduzbinama i endere sa igrama....mloooogo su posteniji....

sto je zanimljivo, blize si istini od hawkingsa. naravno da smo na razini makrokosmosa djelic organizma; na zalost ne i neuroloske celije. bah. :lol:

Quote from: Ugly MF on 28-04-2015, 16:36:48
kakvu funkciju ja imam ako sam ubedjen da je ovaj nas svet isprdjen iz nekog supka i to nazvano BIGBANG....pre nekoliko milijardi godina...?

ali ovo je sasvim drugo pitanje. ako smisao tvog postojanja podrazumeva "X", a ljudi dokažu da nije "X" nego je "Y" što utiče na tvoju percepciju sopstvene svrhe, to ne znači da je i dalje "X" a nije "Y". ti možeš da se preispitaš svoju svrhu, ili možeš da se praviš da je i dalje "X", to je već tebi na volju.

Quote from: zosko on 28-04-2015, 16:27:23
ali nije ni hawking bas neki primjer znanstvenog pristupa; od rada do rada se revidira.

šta tu konkretno nije naučni pristup? pa zar je greh revidirati se?

Quote from: tomat on 28-04-2015, 17:08:23

Quote from: Ugly MF on 28-04-2015, 16:36:48
kakvu funkciju ja imam ako sam ubedjen da je ovaj nas svet isprdjen iz nekog supka i to nazvano BIGBANG....pre nekoliko milijardi godina...?

ali ovo je sasvim drugo pitanje. ako smisao tvog postojanja podrazumeva "X", a ljudi dokažu da nije "X" nego je "Y" što utiče na tvoju percepciju sopstvene svrhe, to ne znači da je i dalje "X" a nije "Y". ti možeš da se preispitaš svoju svrhu, ili možeš da se praviš da je i dalje "X", to je već tebi na volju.

ljudi dokazu,hahaha!
ljudi meni da dokazuju u redu, eto ih neka dokazu.dokaz je da ja na planeti zemlji ne mogu da zivim bez vazduha.svaka cast tom naucniku, volim ga ,dokazano,otidosmo i pod vodu i u svemir od tog dokaza. volim i postujem.
ali da mi neko tupi i svira kurcu sto ne moze da mi tako dokaze i ja da nesto budem vredniji sa tim znanjem,eeee, malo morgen!
kolko je ljudi zbog takvih demagoga propatilo u zivotu i tek ce da pati?
podji samo od udzbenika u osnovnoj,,,,teorije i teorije,od bigbanga do evolucije...

Quote from: tomat on 28-04-2015, 17:09:27
šta tu konkretno nije naučni pristup? pa zar je greh revidirati se?

nije grijeh revidirati se, no koliko to cini hawkings, svrstava se u sf. sva njegova razmisljanja su pod upitnikom. jer prelazi crtu koju je u stanju obuhvatiti empirijski, nagadja na visokoj razini.

Quote from: Ugly MF on 28-04-2015, 17:19:04
kolko je ljudi zbog takvih demagoga propatilo u zivotu i tek ce da pati?

mnogo manje nego onih koji su patili i koji će patiti zbog dogmi.

Nauka se ipak od dogme razlikuje baš po tome što je svaka teorija podložna reviziji.

Quote from: zosko on 28-04-2015, 17:23:33
nije grijeh revidirati se, no koliko to cini hawkings, svrstava se u sf. sva njegova razmisljanja su pod upitnikom. jer prelazi crtu koju je u stanju obuhvatiti empirijski, nagadja na visokoj razini.

za nauku je dobro dok su mu istraživanja pod upitnikom. čovek je teorijski fizičar, njegov posao je da razmišlja na visokoj razini.

Quote from: tomat on 28-04-2015, 17:24:04

Quote from: Ugly MF on 28-04-2015, 17:19:04
kolko je ljudi zbog takvih demagoga propatilo u zivotu i tek ce da pati?

mnogo manje nego onih koji su patili i koji će patiti zbog dogmi.

kojih dogmi,cijih dogmi,kakvih dogmi?

Tomat verovatno hoće da ukaže kako nauka, baš zato što insistira na transparentnosti i proverljivosti (i ponovljivosti rezultata) nema potencijal da bude represivna kao dogma (bilo koja) jer ona, naprotiv, insistira na prostoj reprodukciji.

what Meho said :)

mislim, verovatno je u srednjem veku tvrdnja da je sunce u centru oko kojeg kruži zemlja delovala kao naučna fantastika, al ispalo je da je tako.

edit: sad, kakav je naš benefit od toga što znamo da zemlja kruži oko sunca, ko zna :)

Pa zna se to. Mislim, nema direktne "zarade" na strani društva od toga što je geocentrični model zamenjen heliocentričnim, ali je heliocentrični model bio podsticaj za svemirska istraživanja a ona su bila podsticaj za pravljenje opreme koja može da izdrži put u kosmos i, par decenija kasnije dobili smo teflonske tiganje. Teflon je materijal razvijen u okviru svemirskog programa. Koga verovatno ne bi bilo da je zadržan geocentrični model kosmosa.

Quote from: Meho Krljic on 28-04-2015, 17:39:57
Pa zna se to. Mislim, nema direktne "zarade" na strani društva od toga što je geocentrični model zamenjen heliocentričnim, ali je heliocentrični model bio podsticaj za svemirska istraživanja a ona su bila podsticaj za pravljenje opreme koja može da izdrži put u kosmos i, par decenija kasnije dobili smo teflonske tiganje. Teflon je materijal razvijen u okviru svemirskog programa. Koga verovatno ne bi bilo da je zadržan geocentrični model kosmosa.

i dušeci od memorijske pene :)

jasno je da se zna, ja se samo malo šalim. eno gore okačih link koji prikazuje koristi koje imamo od fizike. bez stvari koje se čine potpuno beskorisnim i nebitnim "običnom" čoveku, kao što je kvantna mehanika, ti i ja bi poruke razmenjivali pismom, a ne preko foruma.

ama opet u redu i za kvantnu mehaniku i teflon, ali crne rupe,eeeej,aman!

nemojmo bre da se vredjamo po inteligenciji...

Quote from: tomat on 28-04-2015, 17:28:13
za nauku je dobro dok su mu istraživanja pod upitnikom. čovek je teorijski fizičar, njegov posao je da razmišlja na visokoj razini.

i kao takav, ne bavi se znanstvenim radom. postavlja hipoteze uz spoznaje koje mu dostupne, pa ih revidira kako mu sine koja nova ideja. pjur sf.

Quote from: Ugly MF on 28-04-2015, 17:51:41
ama opet u redu i za kvantnu mehaniku i teflon, ali crne rupe,eeeej,aman!

nemojmo bre da se vredjamo po inteligenciji...

Šta tačno deluje neverovatno u vezi crne rupe? Koncept da imaš takvu gustinu materije da svetlost ne može da umakne tom gravitacionom polju je prilično lak za razumevanje i objašnjavanje uz korišćenje već osnovnoškolske fizike. Možda tebe nešto drugo tu žulja???

Pitanje zašto imamo toliko teorija mi liči na pitanje zašto tako mnogo spermatozoida učestvuje u oplođavanju. Priroda zna zašto :wink:

Sasvim je u redu da imamo mnogo nepotvrđenih teorija, dokle god su te teorije u skladu sa onim što već znamo. Neke od tih teorija će jednom biti empirijski potvrđene, kao što su i crne rupe empirijski poprilično potvrđene (treba samo kliktati i čitati).

Stvarno, zašto su crne rupe toliko problematične? Meni tu ništa nije problem, savršeno je razumljivo, i kad čovek jednom čuje i razume, posle toga može samo da kaže "pa da, kako mi to i samom nije palo na pamet"... Mislim, nije to kvantna mehanika (koja je daleko nerazumljivija), nego sve savršeno jasno...

hawkingsove teorije su, ako zanemarimo razlicite dimenzije misli autora, jednako vjerodostojne poput onih kako divovska kornjaca nosi svijet na ledjima. kakve crne rupe.

zajeba mi se modify....

Quote from: Meho Krljic on 28-04-2015, 17:56:32

Quote from: Ugly MF on 28-04-2015, 17:51:41
ama opet u redu i za kvantnu mehaniku i teflon, ali crne rupe,eeeej,aman!

nemojmo bre da se vredjamo po inteligenciji...

Šta tačno deluje neverovatno u vezi crne rupe? Koncept da imaš takvu gustinu materije da svetlost ne može da umakne tom gravitacionom polju je prilično lak za razumevanje i objašnjavanje uz korišćenje već osnovnoškolske fizike. Možda tebe nešto drugo tu žulja???

crne rupe su Sf, sta tu ima da zulja?
a sta tebe zulja moja neverica,junace?
kazi cika Frojdu,hmmmm?
cemu tolko obozavanje 'crne rupe'...hehe

Quote from: zosko on 28-04-2015, 18:10:08kakve crne rupe.

Hehe, pa Hoking je više kvantni fizičar nego astronom. Ako ga zaključak u kvantnoj fizici dovede do toga da crne rupe ne mogu da postoje on će se vrlo rado toga držati. To se već desilo, pa je posle morao da se posipa pepelom. Jednom se kladio da izvor Cygnus_X-1 (http://en.wikipedia.org/wiki/Cygnus_X-1) nije crna rupa, ali je sam na kraju priznao da je izgubio opkladu:

QuoteCygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.

Hoking je skoro upravo ustvrdio da idealne crne rupe zapravo ne postoje (http://www.pbs.org/newshour/updates/hawking-meant-black-holes/). Nisam se mnogo udubljivao, i meni je komplikaovano, ali treba samo napomenuti da Hoking ne kaže da ne postoje supermasivni objekti koji nama izgledaju potpuno bez svetla, nego da neko malecno svetlo teoretski ipak može da pobegne i iz najcrnje crne rupe, pa da zato crne rupe nisu 100% crne.

joj,nemoj neko da te cuje da sad ni crne rupe nisu bas i crne nego mlecne, jooooj,,,,i da svetlost ipak moze da pobegne,hehe

Ma, nisu ni rupe. I prava osoba može to zapušiti. Dart Džek je pisao o tom heroju. :-|

Da staneš ispred crne rupe video bi totalno crnilo, a ova teorijska začkoljica bi bila potpuno bez značaja.

To je sve zbog kvantne mehanike, koja je još zaguljenija od opšte teorije relativnosti, i iskreno, nije mi jasno kako ti relativnost nije po volji, a kvantovi jesu. Does not compute.

meni je relativnost Sve!...osim jedne stvari...

mislio sam da se zove teorija relativiteta,valjda je to isto,relativnost...
a ti kvantovi, ako nam je to pomoglo da nam procesori u kompu danas brze rade,onda su mi okej,sto da ne....
ali da smo svi ovolko isprdak dzinovskog cmara, e bemu teoriju....misliiim,
kom to uopste treba?

Quote from: Ugly MF on 28-04-2015, 19:51:46

ali da smo svi ovolko isprdak dzinovskog cmara...

Sve zavisi sa koje si strane.

Quote from: Ugly MF on 28-04-2015, 18:26:32

Quote from: Meho Krljic on 28-04-2015, 17:56:32

Quote from: Ugly MF on 28-04-2015, 17:51:41
ama opet u redu i za kvantnu mehaniku i teflon, ali crne rupe,eeeej,aman!

nemojmo bre da se vredjamo po inteligenciji...

Šta tačno deluje neverovatno u vezi crne rupe? Koncept da imaš takvu gustinu materije da svetlost ne može da umakne tom gravitacionom polju je prilično lak za razumevanje i objašnjavanje uz korišćenje već osnovnoškolske fizike. Možda tebe nešto drugo tu žulja???

crne rupe su Sf, sta tu ima da zulja?
a sta tebe zulja moja neverica,junace?
kazi cika Frojdu,hmmmm?
cemu tolko obozavanje 'crne rupe'...hehe

Ma kakvo obožavanje, nego nisam siguran zašto je Crna Rupa neprihvatljiv koncept u dvadesetprvom veku. Mislim, svakako da ja, sa svojom osnovnoškolskom fizikom ne bih umeo da te korak po korak provedem kroz ideju da foton ima masu kada se kreće i da ta masa sasvim uobičajeno interaguje sa masom onog što zovemo Crnom Rupom i da pošto je gustina mase velika, gravitaciono polje biva veoma snažno i to fotonu ne da da pobegne itd. ali već neki profesor fizike za osnovnu školu bi umeo, dakle, nije to neko sad supertajno, ezoterično znanje u koje se samo može verovati a koje se ne može dokazivati (uz pretpostavku da se prihvataju osnovne postavke fizike).

ma meni su mnoge stvari neprihvatljive, pa ih ima u 21.veku....demokratija, lgtb prava, islam, sns, crne rupe....

Твој живот је ПАКАО!!!!!!!!!!!! (Ćirilica radi dojma)

Ali neće ni njihova do zore.

Black Hole Sun- Soundgarden (http://www.youtube.com/watch?v=RBXGxgreM1k#)

Ubij, ubij, ubij crnu rupuuu, crnu rupuuu, crnu ruuupuuuuuuu

Ili

Ubij, zakolji, da crna rupa ne postoji

Ili

Crna rupa gradom neće šetati

sad jos samo nedostaje stevo da kaze, crna rupa? nix, pa hoce lijepo ili kroz dimnjak!

Quote from: tomat on 28-04-2015, 21:05:18
Ubij, ubij, ubij crnu rupuuu, crnu rupuuu, crnu ruuupuuuuuuu

Ili

Ubij, zakolji, da crna rupa ne postoji

Ili

Crna rupa gradom neće šetati

hilarijus!
anbilivabl!
kakva originalnost,ljudi moji, pa da li je to moguce!?

el treba da promenim nick u recimo....Konzervirani Bigot Homofobijus...ili slicno......

meho,
Аркона (Arkona) - Сербия (Serbia) (http://www.youtube.com/watch?v=9dkvT6EwAlY#ws)

Agli, ne znam šta ti tačno smeta kod crnih rupa. to što crne rupe postoje ne znači da je svemir obavezno nastao iz crne rupe. a i da je nastao, to ne mora da isključi tvorca. ne vidim kako bi dokazi da crne rupe postoje morali i mogli da utiču na tvoje stavove, načela, principe, smisao tvog postojanja, ...

ja nigde ne pomenuh ni svoju religiju ovde, ni tvorca, niti su bitni svi moji stavovi o svemu i svacemu, to si se ti malo prvi nadovezao, i o tome cu na drugim topikcima....
A ja moram da priupitam sada, sta to ima nekome da smeta sto, pazi sad, JA odbijam da poverujem u TEORIJU da crne rupe uopste postoje.Upitnik....: ?

...da razglabamo, mozda je zemlja stara 6.000 godina mozda 6.000.000.000, relativno ,dal je kreacija od boga isla putem evolucije,pffff,zabole me se zamaram s tim.....de cu odem kad crknem, a de sam sad, opet moz' naglabamo tamo i vamo.....

mozda se i sunce i ostale planete okrecu oko zemlje, ama ima x stvari koje moz ovako i onako, i za njih me zabole,,,,

.....ali eto, ja ne verujem u TEORIJU da crne rupe postoje...
a konkretno, nista mi ne smeta doklen god ih gledam u SF.....do jaja su mi....

Pa ne postoji takva teorija. Nema toga. Postoji Ajnštajnova teorija, a super masivni objekti u narodu poznati kao crne rupe po Ajnštajnovoj teoriji imaju tu osobinu da se njihova svetlost ne vidi. Drugim rečima, ne veruješ u Ajnštajnovu teoriju?

i einsteinova teorija je relativna. ne vjerujem da smo obuhvatili tek naznake svijeta oko nas, kamo li u stanju izvoditi zakljucke iz tih krnjih matematickih modela...

Pa, to sve možda stoji ali šta konkretno zvuči neverovatno u konceptu crne rupe?? Ako neko veruje u ostatak astrofizike, šta posebno izdvaja crne rupe kao generator neverice?

iskustvo. znamo da jedni svoje teorije prodaju kao sf, drugi znanost. price o crnim rupama su maminovac.
sutra ce reci, oh, sorry, nije crna rupa, bila muha na objektivu... ali sad smo izracunali bijelu elipsu!

verujem u njegovu E=mc2, ta je dokazana....
a cim si ti definisao,ili ajnstajn, da nesto mozda postoji,na osnovu necega,ono mozda automatski stvara teoriju,
tako da teorija o crnim rupama postoji....ima ih vise, jedna kaze da BlackHoleSun moze da bidne WormHole,,,

e, ja ne verujem ni u jednu od tih teorija....
jooooj,jednom sam se ovako preganjo s jednim da ne postoji reinkarnacija,on bio ubedjen da je bio puz....ili sam to ja citao Loba....?

Neverovatna je upornost u odbrani crne rupe do poslednjeg posta. Ugly neće da veruje u crnu rupu, pa šta? Jel' će se neka rupa žaliti nadležnom ministarstvu? Tužiće nas EU za rodno nepoštovanje?

Ja samo želim da otkrijem kakva je crna magija po sredi, ništa više. Šta ako se proširi neka moda međ narodom, gde ljudi prosto ne žele da poveruju ne samo u postojanje već dokazanih astronomskih fenomena (crne rupe, pulsari, kvazari, supernove, crna materija, galaktička super-jata, braon patuljci) nego i u neke druge stvari koje nisu videli svojim očima (bacili, virusi, vakcine, promena klime, spuštanje na Mesec i Mars)? Te mode su opasne. Posledica masovnog neverovanja može negativno da utiče i na mene lično. Bolje da se pripremim sada, makar neverovanje u crne rupe nikad ne bude omasovljeno, jer će neverovanje u nešto drugo sigurno biti.

e, sad je dosta.
mac, sirotinjo duhovna i intelektualna!
znaci ko ne veruje u nesto tvoje, odmah je jeretik i treba masovno sve takve potamaniti, jer se ti takvih kolko vidim plasis?
to te naucili ovi sto poturaju slobode i jednakosti? po toj tvojoj logici ,spremte se spremte, pa priemptiv strajk?
to ti je moderna demokratija? ko sumnja u tvoje dogme,crnomagijas?

bajdvej, ti opisujes sukob dve religije ovde,(religija znaci ponovno spajanje sa Bogom od koga smo se odvojili,bajdvej),i dok neko mirno iznese svoje misljenje,tebi kome se isto ne svidja, odmah smatras za jeres!
klasican inkvizitor i dzihadist,mac,nista drugo!
samo nisu ti Isus ni Allah vec Nauka naziv tvog Boga....uffff jaka razlika, princip isti...ovi su imali krstaske ratove,ovi dzihad, ameri uterivanje demokratije, tebi je trenutno maltretiranje po forumima....

jos ne mogu da poverujem sta sve proizvede drugacije misljenje o totalno nebitnoj stvari kao sto su crne rupe....
a Quassari su mi omiljeni, najlepsi,bas sam se odusevio daaaavno kad sam gutao sve to....ali takodje Teorija o njima dal postoje mi je nebitna.....moz' i tako, a moz' iovako....

Malo skepse nikada nije na odmet. Nauka nikad ne bi stigla dovde, da je nije bilo. Meni je malo previše teorija sačinjeno da bi neke druge teorije opstale. Ne čini li ti se da je i Ajnštajnova konstanta C malo obajatila. Već neko vreme su u opticaju uslovi pod kojima nije konstanta. Tako da i nije sasvim brzina svetlosti. Uostalom, sve konstante su samo nepotpuno razjašnjeni deo neke jednačine. Liči na konstantu, ali i nije sasvim. Dug put smo prešli od Njutna do Ajnštajna, ali će se nastavak još dugo graditi.

Okej znači Tomat je u pravu, ipak je religija. Još samo da utvrdimo gde se to religija kosi sa crnim rupama, ko je to rekao, i kako je do toga došao... Zar nemaju u Rimu naučni tim, koji se uglavnom slaže sa većinom onoga što nauka ustanovi, uključujući i crne rupe?

Nisu crne rupe "moje". Da su moje zvale bi se macove rupe, ili macovo crnilo, ili šta već. Neki drugi, učeniji, ljudi su se svega toga dosetili, ponajpre Ajnštajn, a kasnije i empirijski potvrdili (http://www.universetoday.com/22104/beyond-any-reasonable-doubt-a-supermassive-black-hole-lives-in-centre-of-our-galaxy/).

Takođe, skepsa je ne samo poželjna, nego i neophodna. Esencijalna zapravo. Sve se mora stalno proveravati. Ali "nevjeruju" nije isto što i skepsa. Razlika je što ti za skepsu treba racio. Kad kažeš ne verujem u crne rupe jer fotoni nemaju masu, pa prema tome gravitacija nikako ne može na njih da utiče, to je skepsa. Kad kažeš ne verujem u crne rupe, ste normalni, šta vam je, to nije skepsa.

"Undoubtedly the most spectacular aspect of our 16-year study, is that it has delivered what is now considered to be the best empirical evidence that super-massive black holes do really exist," Genzel continues. "The stellar orbits in the galactic centre show that the central mass concentration of four million solar masses must be a black hole, beyond any reasonable doubt."

a ja kazem da kenja ko foka....eto, moje misljenje...
isti takvi su nam poturali i da vanzemaljci postoje...i da su ih ameri snimili...
i da su bili na mesecu,,,,i to su snimili....
i da su Srbi pobili toliko shiptara da su morali da bace bombe....
i da sad ISIS roka po celom svetu, ali zaboga, to se sad nikog ne tice....
...i da ko nece da se zaduzi kod MMFa imaa da popije bombe-(u ovo ustvari verujem)....

"A ja kažem da kenja ko foka" je obično mesto u raspravi gde treba da se napravi muzički intermeco. Evo!



Einstein vs Stephen Hawking -Epic Rap Battles of History #7 (http://www.youtube.com/watch?v=zn7-fVtT16k#ws)

evo i ja da dodam

MC Hawking - Biz Bizang (http://www.youtube.com/watch?v=mf5QJqVVf74#ws)

Јасно вам је да је ово морало да дође прије или касније?

Decostructing Harry (Black Hole dialogue) (http://www.youtube.com/watch?v=tGqrL8hVzXI#ws)

evo cemu sluze crne rupe...
http://www.imdb.com/title/tt0078869/ (http://www.imdb.com/title/tt0078869/)

Mala meditacija o hlađenju univerzuma i tome gde je mesto inteligentnom životu u kosmosu ohlađenom na desetmilioniti deo stepena Kelvina i sastavljenom od samih crnih rupa i po kog tračka Hokingove radijacije...


Learning to Chill (https://medium.com/starts-with-a-bang/learning-to-chill-cd8f4fe607d4)
What would intelligent life look like in the frigid, final era of the Universe? (https://medium.com/starts-with-a-bang/learning-to-chill-cd8f4fe607d4)

Još interesantnih priča o crnim rupama. Između ostalog obrazlaže da mislimo da postoje jer se mnogi astronomski i astrofizički fenomeni koje posmatramo najjednostavnije i najlogičnije objašnjavaju crnim rupama (tj. masivnim gravitacionim bunarima) a onda i razmatra da li crne rupe imaju neki poseban oblik.




Astroquizzical: does a black hole have a shape? (https://medium.com/starts-with-a-bang/astroquizzical-does-a-black-hole-have-a-shape-3fbb01b13843)





http://youtu.be/pj2iFCfDmHY (http://youtu.be/pj2iFCfDmHY)

Pa valjda smo ih "videli" i u Interstellaru, to mu je kao najjača tačka  xrotaeye

Nismo videli dve zajedno. Možda će to da prikažu u nastavku...

Interstellar 2: Clash of the Titans. Now with 100% more black holes!!!!!!!!!

A crazy new theory solves 40-year-old mystery about what happens inside of a black hole (http://finance.yahoo.com/news/crazy-theory-solves-age-old-165905743.html)

Quote
There's a common notion that at the edge of every black hole lies a back door to the universe — an exit from reality into a new realm where fundamental laws of nature, like time, no longer behave the way that we understand them.

What happens once you cross this threshold is a long-standing mystery that the world's leading scientists have been pondering for decades with little headway.

Now, a recent paper (http://arxiv.org/abs/1506.04342) presented at a conference in Paris this week has proposed a solution by looking at black holes in a completely different way.

Taking a novel approach to this age-old problem, the theory proposes that there is no back door to the universe in the first place. Instead, black holes are impenetrable bodies, called fuzzballs.
Fuzzballs (yes, fuzzballs) are the new black holes
Samir Mathur, a professor of physics at The Ohio State University and sole author of the paper, says as you approach the fuzzball, your body will be destroyed but, oddly enough, you will not die. Rather, you'll be transformed into a copy of yourself, in the form of a hologram, that is forever embedded onto the surface of the fuzzball.


Mathur describes the surface (https://www.physics.ohio-state.edu/~mathur/fuzzballparadigm.pdf) as a thin fuzzy region of space instead of smooth, distinct feature, which is how he came up with the name "fuzzball".

When he first announced his fuzzball theory in 2003, it excited the scientific community (http://researchnews.osu.edu/archive/fuzzball.htm) because it offered a resolution to an outstanding paradox about black holes.

This paradox was originally discovered by astrophysicist Stephen Hawking more than 40 years ago and scientists have been attempting to explain it ever since.

However, Mathur's original calculations didn't conform to other well-established theories that describe the nature of black holes. So, he's spent over 15 years molding and maturing his argument.

Now, his latest paper has taken a significant step forward, suggesting that his picture of black holes as the holographic copy machines of the universe, while bizarre, could mean that fuzzballs truly are how scientists should be thinking about these mysterious cosmic beasts to better understand their behavior.

But some scientists are skeptical (http://phys.org/news/2015-06-surface-black-hole-firewalland-nature.html) of Mathur's conclusions. Although they support his novel view of black holes, they suggest you won't survive your encounter with a fuzzball, at all, but suffer a fiery death.
The most extreme environments in spaceWhat makes black holes so exotic is their powerful gravitational grip, which acts like a deep well in space, warping the space and time around and within.

Moreover, this grip has the power to swallow everything that passes too close, including light. This means anything that falls into the well never returns, which makes it nearly impossible to determine what happens beyond the edge of a black hole.

That didn't stop Hawking from first attempting to find some answers in the early '70s.

Unlike Mathur, Hawking pictured black holes with back doors through which material was pulled by gravity. So, Hawking began to explore what happens just outside of that door, moments before crossing over to the dark side for eternity.

What he found in 1976 from following the well-established laws of physics originally set down by Albert Einstein (https://en.wikipedia.org/wiki/General_relativity) and Paul Dirac (https://en.wikipedia.org/wiki/History_of_quantum_field_theory) and many others, was shocking: Black holes don't just consume material through their back doors. They also emit it in the form of radiation.
A pesky paradox
While this was a momentous discovery — the radiation has since been named Hawking radiation — it generated a perplexing issue, called the black hole information paradox, that scientists have yet to resolve.
Hawking radiation is generated from whatever falls first into a black hole, according to Hawking's theory.

Some of what falls in gets spit back out while the rest is trapped inside of the black hole, where it's eventually destroyed and lost forever. This is where the paradox arises: One of the most fundamental concepts in physics states that no material in the universe can be completely lost or destroyed, which directly contradicts Hawking's original assumption.

Other than that small problem, the famous astrophysicist's logic was fool proof. And scientists today, including Mathur, still consider Hawking radiation a plausible component of black holes, although it has yet to be observed.

Nearly 30 years later, Hawking hasn't offered a convincing solution to the paradox he discovered, but Mathur might have. What Mathur has done differently is to think of black holes as a solid surface that has no back door.
Solving the information paradox
The fuzzball black holes that Mathur pictures are impenetrable and, therefore, don't have a region where material can fall into them. Rather, any object attracted by a fuzzball's gravitational pull will fall onto the surface.
When that happens, a near-perfect copy of the objects is created in the form of a hologram. That hologram goes on to live on the surface of the black hole, while the original copy feeds the fuzzball.

"The original copy is destroyed. More precisely, the data making up the original copy gets transformed to a new form, which is data on the surface of the fuzzball," Mathur told Business Insider in an email. "When matter falls on the surface, this surface gets more energy, and it expands."

When Mathur was first exploring this theory at the turn of the century, his original calculations suggested that your holographic twin was a perfect copy of your original self. However, other scientists argued that a perfect copy was impossible because the universe tends to favor imperfection (https://www.facebook.com/NOVAonline/videos/10152710760662196/).

Mathur's latest paper resolves this issue, showing how slightly altered copies could be possible.

From this, Mathur has managed to settle the black hole information paradox in two ways:

   
• By removing the exotic realm inside a black hole where information is mysteriously destroyed and lost forever.
• By explaining exactly what happens to material as it reaches a black hole and how all of it is preserved and none is lost.

"The fuzzball structure resolves this paradox; that is the reason I believe in it," Mathur told Business Insider.
Strings of fuzzballs
To explain his assumptions mathematically, Mathur relies on a theoretical framework in physics called string theory (https://en.wikipedia.org/?title=String_theory), which suggests that all particles in the universe are made of tiny, one-dimensional strings that vibrate and interact with one another to generate the universe around us.
(This idea is controversial since no one has ever observed a string. Still, string theory offers convincing solutions to some outstanding scientific mysteries like quantum gravity (https://medium.com/starts-with-a-bang/ask-ethan-91-does-quantum-gravity-need-string-theory-f1d424137b03) — also referred to as a "unified theory of everything (https://www.iusb.edu/currents/a-unified-theory-of-everything/)" — so physicists are reluctant to scrap it just yet.)

Mathur's fuzzball black holes are actually giant, balled-up collections of strings. So, theoretically, when an object touches the surface of the fuzzball, its mass gets converted into light, generating a holographic copy of its former self. Other string theorists disagree, though.

Building upon Mathur's logic, a team of physicists at the University of California proposed in 2012 (http://download.springer.com/static/pdf/448/art%253A10.1007%252FJHEP02%25282013%2529062.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2FJHEP02%282013%29062&token2=exp=1434724955%7Eacl=%2Fstatic%2Fpdf%2F448%2Fart%25253A10.1007%25252FJHEP02%2525282013%252529062.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252FJHEP02%25282013%2529062*%7Ehmac=6312ebd6eb4904681c053ff19eb0b36855e76346942dfcedefff6921e73c23b7) that anything falling onto the surface of a fuzzball would immediately be "burned to a crisp" and die. This group's "firewall" theory divided the scientific community into supporters of fuzzballs versus supporters of firewalls.

One way to resolve the issue would be a scientific experiment.

"It is hard to check the fuzzball structure explicitly by an experiment," Mathur told Business Insider in an email. "One way would be if we could ever make tiny black hole in an accelerator like [those at] CERN (http://home.web.cern.ch/about)."

Particle accelerators slam particles together at near the speed of light, which can generate extreme environments that are similar to the early universe. Whether the world most powerful accelerators at CERN (European Organization for Nuclear Research) can produce tiny black holes this way is questionable.

Regardless, there is a growing group of scientists around the world in support of Mathur's idea who are exploring different facets of the theory. The deeper they dig, the more likely they'll discover the truth of fuzzballs.

Itan Zigel:

Why The Black Hole Information Paradox Is Such A Problem (http://www.forbes.com/sites/ethansiegel/2015/09/05/why-the-black-hole-information-paradox-is-such-a-problem/)

More Evidence for Coming Black Hole Collision (http://www.nytimes.com/2015/09/22/science/space/more-evidence-for-coming-black-hole-collision.html?partner=rss&emc=rss&_r=0)

Quote

The apocalypse is still on, apparently — at least in a galaxy about 3.5 billion light-years from here.
Last winter a team of Caltech astronomers reported (http://www.nytimes.com/2015/01/08/science/in-a-far-off-galaxy-2-black-holes-dance-toward-an-explosive-union.html) that a pair of supermassive black holes appeared to be spiraling together toward a cataclysmic collision that could bring down the curtains in that galaxy.
The evidence was a rhythmic flickering from the galaxy's nucleus, a quasar known as PG 1302-102, which Matthew Graham and his colleagues interpreted as the fatal mating dance of a pair of black holes with a total mass of more than a billion suns. Their merger, the astronomers calculated, could release as much energy as 100 million supernova explosions, mostly in the form of violent ripples in space-time known as gravitational waves that would blow the stars out of that hapless galaxy like leaves off a roof.
Now a new analysis of the system by Daniel D'Orazio of Columbia University and his colleagues has added weight to that conclusion. Mr. D'Orazio, a graduate student, and his colleagues Zoltan Haiman and David Schiminovich propose that most of the light from the quasar is coming from a massive disc of gas surrounding the smaller of the two black holes.
As the black holes and their attendant discs swing around each other at high speeds, the light from the disk that is coming toward us gets a boost from relativistic effects – a so-called Doppler boost — the same way a siren gets louder and more high-pitched as it approaches, giving rise to a periodic increase in brightness every five years.
The Columbia astronomers' model predicts that the variation would be two or three times greater in ultraviolet light than in visible light. And that is exactly what they found when they compared archival data from the Hubble Space Telescope (http://topics.nytimes.com/top/news/science/topics/hubble_space_telescope/index.html?inline=nyt-classifier) and NASA's Galex space telescope (http://science.nasa.gov/missions/galex/) to the visible-light data previously analyzed by Dr. Graham's group.
"What's big is that the Doppler boost is inevitable," Dr. Haiman said in an email. Given reasonable assumptions about the masses of the two black holes, their model predicts the right ultraviolet data. "This is rare in 'messy' astronomy," he said, "to have an indisputable clean effect, which explains the data." Follow-up observations of ultraviolet and visible light emissions in the coming years could help the clinch the case, the authors said. Their paper (http://nature.com/articles/doi:10.1038/nature15262) was published on Wednesday in the journal Nature.
Their model suggests that the black holes are orbiting each other at a distance of some 200 billion miles, less than a tenth of a light-year, a cosmic whisker. At that distance the black holes would be rapidly losing energy by radiating gravitational waves and could spiral together into the final bang in as little as 100,000 years, Dr. Haiman said, depending on their relative masses.
"Basically, the more massive the holes, the faster gravitational waves drive them together, and we do require them to be as massive as allowed to be," he said in an email. For their model to hold up, the larger of the black holes has to be a billion solar masses or more. Advertisement
  Continue reading the main story (http://www.nytimes.com/2015/09/22/science/space/more-evidence-for-coming-black-hole-collision.html?partner=rss&emc=rss&_r=0#story-continues-6)   Advertisement
  Continue reading the main story (http://www.nytimes.com/2015/09/22/science/space/more-evidence-for-coming-black-hole-collision.html?partner=rss&emc=rss&_r=0#story-continues-6) E. Sterl Phinney, a Caltech astronomer and expert on supermassive black holes currently on sabbatical at Radboud University in the Netherlands, agreed that Dr. Haiman's model explains the quasar variations. "So Occam's razor makes it attractive," he said in an email, referring to the long-held principle that physicists should adopt the simplest theory that fits the facts.
But it was surprising, he said, to find a pair of supermassive black holes that have gotten so close.
Black holes, (http://www.nytimes.com/2015/06/09/science/black-hole-event-horizon-telescope.html) predicted by Albert Einstein's general theory of relativity, the prevailing theory of gravity, are objects so dense that not even light can escape from them. In effect they are bottomless pits in space-time. Every galaxy of note seems to have a supermassive black hole, weighing millions or billions of times as much as the sun, burping sparks of half-eaten stars and gas.
When galaxies merge, their resident black holes are sent into forced marriages, orbiting each other. But without gravitational interactions with stars or interstellar gas, supermassive black holes can't get close enough to each other to go into a rapid death spiral, a situation known as the "final parsec" problem. (A parsec is the astronomical standard of distance, 3.26 light-years.)
So, as Dr. Phinney explained, unless hundreds of millions of solar masses of gas accompany the black holes, "there are not very convincing ways of getting them to smaller separations" like the black holes in PG 1302-102.
At least that is the theory. If such systems are common, Dr. Phinney said, the gravitational waves emanating from them should sweep the universe and disrupt the timing of signals from pulsars, an effect that could be detected within the next few years by various ongoing programs to time pulsars.
"A scientific theory is only as good as the tests which it has passed," Mr. D'Orazio said in an email. Although general relativity has passed all of the observational and experimental tests thrown at it so far, some of its predictions can only be tested in the most extreme gravitational environments, namely black holes. "Detection of gravitational waves," he said, "is a direct probe of this region and hence the secrets of gravity."

Physicists figure out how to retrieve information from a black hole (http://news.sciencemag.org/physics/2015/12/physicists-figure-out-how-retrieve-information-black-hole) 

Quote
Black holes earn their name because their gravity is so strong not even light can escape from them. Oddly, though, physicists have come up with a bit of theoretical sleight of hand to retrieve a speck of information that's been dropped into a black hole. The calculation touches on one of the biggest mysteries in physics: how all of the information trapped in a black hole leaks out as the black hole "evaporates." Many theorists think that must happen, but they don't know how.
Unfortunately for them, the new scheme may do more to underscore the difficulty of the larger "black hole information problem" than to solve it. "Maybe others will be able to go further with this, but it's not obvious to me that it will help," says Don Page, a theorist at the University of Alberta in Edmonton, Canada, who was not involved in the work.
You can shred your tax returns, but you shouldn't be able to destroy information by tossing it into a black hole. That's because, even though quantum mechanics deals in probabilities—such as the likelihood of an electron being in one location or another[/size]—the quantum waves that give those probabilities must still evolve predictably, so that if you know a wave's shape at one moment you can predict it exactly at any future time. Without such "unitarity" quantum theory would produce nonsensical results such as probabilities that don't add up to 100%.
But suppose you toss some quantum particles into a black hole. At first blush, the particles and the information they encode is lost. That's a problem, as now part of the quantum state describing the combined black hole-particles system has been obliterated, making it impossible to predict its exact evolution and violating unitarity.
Physicists think they have a way out. In 1974, British theorist Stephen Hawking argued that black holes can radiate particles and energy. Thanks to quantum uncertainty, empty space roils with pairs of particles flitting in and out of existence. Hawking realized that if a pair of particles from the vacuum popped into existence straddling the black hole's boundary then one particle could fly into space, while the other would fall into the black hole. Carrying away energy from the black hole, the exiting Hawking radiation should cause a black hole to slowly evaporate. Some theorists suspect information reemerges from the black hole encoded in the radiation[/size]—although how remains unclear as the radiation is supposedly random.
Now, Aidan Chatwin-Davies, Adam Jermyn, and Sean Carroll of the California Institute of Technology in Pasadena have found an explicit way to retrieve information from one quantum particle lost in a black hole (http://arxiv.org/abs/1507.03592), using Hawking radiation and the weird concept of quantum teleportation.
Quantum teleportation (https://en.wikipedia.org/wiki/Quantum_teleportation) enables two partners, Alice and Bob, to transfer the delicate quantum state of one particle such as an electron to another. In quantum theory, an electron can spin one way (up), the other way (down), or literally both ways at once. In fact, its state can be described by a point on a globe (https://en.wikipedia.org/wiki/Bloch_sphere) in which north pole signifies up and the south pole signifies down. Lines of latitude denote different mixtures of up and down, and lines of longitude denote the "phase," or how the up and down parts mesh. However, if Alice tries to measure that state, it will "collapse" one way or the other, up or down, squashing information such as the phase. So she can't measure the state and send the information to Bob, but must transfer it intact.
To do that Alice and Bob can share an additional pair of electrons connected by a special quantum link called entanglement (http://news.sciencemag.org/physics/2015/08/more-evidence-support-quantum-theory-s-spooky-action-distance). The state of either particle in the entangled pair is uncertain[/size]—it simultaneously points everywhere on the globe[/size]—but the states are correlated so that if Alice measures her particle from the pair and finds it spinning, say, up, she'll know instantly that Bob's electron is spinning down. So Alice has two electrons[/size]—the one whose state she wants to teleport and her half of the entangled pair. Bob has just the one from the entangled pair.
To perform the teleportation, Alice takes advantage of one more strange property of quantum mechanics: that measurement not only reveals something about a system, it also changes its state. So Alice takes her two unentangled electrons and performs a measurement that "projects" them into an entangled state. That measurement breaks the entanglement between the pair of electrons that she and Bob share. But at the same time, it forces Bob's electron into the state that her to-be-teleported electron was in. It's as if, with the right measurement, Alice squeezes the quantum information from one side of the system to the other.
Chatwin-Davies and colleagues realized that they could teleport the information about the state of an electron out of a black hole, too. Suppose that Alice is floating outside the black hole with her electron. She captures one photon from a pair born from Hawking radiation. Much like an electron, the photon can spin in either of two directions, and it will be entangled with its partner photon that has fallen into the black hole. Next, Alice measures the total angular momentum, or spin, of the black hole[/size]—both its magnitude and, roughly speaking, how much it lines up with a particular axis. With those two bits of information in hand, she then tosses in her electron, losing it forever.
But Alice can still recover the information about the state of that electron (http://arxiv.org/abs/1507.03592), the team reports in a paper in press at Physical Review Letters. All she has to do is once again measure the spin and orientation of the black hole. Those measurements then entangle the black hole and the in-falling photon. They also teleport the state of the electron to the photon that Alice captured. Thus, the information from the lost electron is dragged back into the observable universe.
Chatwin-Davies stresses that the scheme is not a plan for a practical experiment. After all, it would require Alice to almost instantly measure the spin of a black hole as massive as the sun to within a single atom's spin. "We like to joke around that Alice is the most advanced scientist in the universe," he says.
The scheme also has major limitations. In particular, as the authors note, it works for one quantum particle, but not for two or more. That's because the recipe exploits the fact that the black hole conserves angular momentum, so that its final spin is equal to its initial spin plus that of the electron. That trick enables Alice to get out exactly two bits of information[/size]—the total spin and its projection along one axis[/size]—and that's just enough information to specify the latitude and longitude of quantum state of one particle. But it's not nearly enough to recapture all the information trapped in a black hole, which typically forms when a star collapses upon itself.
To really tackle the black hole information problem, theorists would also have to account for the complex states of the black hole's interior, says Stefan Leichenauer, a theorist at the University of California, Berkeley. "Unfortunately, all of the big questions we have about black holes are precisely about these internal workings," he says. "So, this protocol, though interesting in its own right, will probably not teach us much about the black hole information problem in general."
However, delving into the interior of black holes would require a quantum mechanical theory of gravity. Of course, developing such a theory is perhaps the grandest goal in all of theoretical physics, one that has eluded physicists for decades.
 

 A five-dimensional black hole could 'break' general relativity, say physicists (http://www.sciencealert.com/a-five-dimensional-black-hole-could-break-general-relativity-say-physicists)

QuoteIf you thought regular black holes were about as weird and mysterious as space gets, think again, because for the first time, physicists have successfully simulated what would happen to black holes in a five-dimensional world, and the way they behave could threaten our fundamental understanding of how the Universe works.
The simulation has suggested that if our Universe is made up of five or more dimensions - something that scientists have struggled to confirm or disprove - Einstein's general theory of relativity, the foundation of modern physics, would be wrong. In other words, five-dimensional black holes would contain gravity so intense, the laws of physics as we know them would fall apart.
There's a lot to wrap your head around here, so let's start with the black holes themselves. In a five-dimensional universe, physicists have hypothesised that black holes are more like very thin rings rather than holes, and as they evolve, they can give rise to a series of 'bulges' that become thinner and thinner over time, and eventually break off to form mini black holes elsewhere.
These ring-shaped black holes (or 'black rings') were first proposed in 2002 (http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.88.101101), but until now, no one's been able to successfully simulate their evolution. This has been made possible thanks to the COSMOS supercomputer at the University of Cambridge in the UK - the largest shared-memory computer in Europe that can perform 38.6 trillion calculations per second (http://phys.org/news/2014-06-cosmos-supercomputing-facility-intel-parallel.html). 



The problem with five-dimensional black holes is that they're thought to consist of 'ultragravity rings', where gravity is so intense, it gives rise to a state known as naked singularity (http://io9.gizmodo.com/5825098/whats-so-scandalous-about-a-naked-singularity). Naked singularity is an event so strange, no one really knows what would occur, except that the laws of general relativity would no longer apply.
Einstein's general theory of relativity is based on how we think gravity governs the behaviour of the Universe. We know that matter in the Universe warps the surrounding fabric of spacetime, and this warping effect is what we refer to as gravity. Since it was first proposed 100 years ago (http://www.sciencealert.com/here-s-how-einstein-s-general-theory-of-relativity-killed-off-common-sense-physics), general relativity has passed every test - everything we observe in the Universe follows its stipulations, but singularity can pose some problems. 
In a four-dimensional universe (where the fourth dimension is time), singularity is thought to be the point of a black hole where gravity is at its most intense - the centre - and this is surrounded by the event horizon at the black hole's edge. 
"As long as singularities stay hidden behind an event horizon, they do not cause trouble and general relativity holds - the 'cosmic censorship conjecture' (https://en.wikipedia.org/wiki/Cosmic_censorship_hypothesis) says that this is always the case," says theoretical physicist Markus Kunesch (http://phys.org/news/2016-02-five-dimensional-black-hole-relativity.html) from the University of Cambridge. "As long as the cosmic censorship conjecture is valid, we can safely predict the future outside of black holes."
But what if singularity could exist outside a black hole's event horizon? When Physicists have hypothesied that in five or more dimensions, if an object that has collapsed to an infinite density - singularity - is not bound by an event horizon, it becomes naked singularity, and things would get so crazy in and around that object, we'd need to completely rethink our understanding of how physics works. The whole thing just makes me really nervous.
"If naked singularities exist, general relativity breaks down," said one of the team (http://phys.org/news/2016-02-five-dimensional-black-hole-relativity.html), Saran Tunyasuvunakool. "And if general relativity breaks down, it would throw everything upside down, because it would no longer have any predictive power - it could no longer be considered as a standalone theory to explain the Universe."
If our Universe only has four dimensions, everything is cool, and ring-shaped black holes and naked singularity are not a thing. But physicists have proposed that our Universe could be made up of as many as 11 dimensions (http://www.universetoday.com/48619/a-universe-of-10-dimensions/). The problem is that because humans can only perceive three (http://phys.org/news/2016-02-five-dimensional-black-hole-relativity.html), the only way we can possibly confirm the existence of more dimensions is through high-energy experiments such as the Large Hadron Collider.
Kunesch and his team say they've just about hit the limits of what their supercomputer can simulate, but would like to figure out what it is about four-dimensional universes that make naked singularity impossible, and general relativity correct. "If cosmic censorship doesn't hold in higher dimensions, then maybe we need to look at what's so special about a four-dimensional universe that means it does hold," says Tunyasuvunakool. (http://phys.org/news/2016-02-five-dimensional-black-hole-relativity.html)
The study has been published in Physical Review Letters, (http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.071102) and for more on those 11 dimensions, here's theoretical physicist, Michio Kaku:

http://youtu.be/jI50HN0Kshg (http://youtu.be/jI50HN0Kshg)

'we believe, but we can not yet proove' :D

Pa, tako mu je to u nauci: ponudi se model koji deluje najverovatnije u svetlu onoga što možemo da dokažemo, rade se simulacije koje ukazuju da je tačan, ali niko neće da tvrdi da je on actually tačan dok nema taj neki proverljiv dokaz itd.

Naravno, ovde pričamo o tako zamumuljenim astrofizičkim fenomenima da "proverljiv dokaz" podrazumeva ogroman budžet na strani obrazovanja i opreme od strane bilo kog ko bi to želeo da proveri. Al dobro, niko nije rekao da je granična nauka nešto što mase treba da troše na nivou lake dnevne zabave.  :lol: :lol: :lol:

Ovo je tema o hiper crnim rupama. Tu mora da padne teško teoretisanje. Cenim da ne samo da je pošteno od njih što kažu da ne mogu da dokažu, nego je i savršeno normalno i očekivano.

Podsmevaš se ovim teoretskim naučnicima što veruju bez dokaza, uz implicitnu tvrdnju da je to potpuno isto kao i kad religiozna osoba veruje bez dokaza, ali postoji par fundamentalnih razlika. Prvo, dokaza nema trenutno, ali ako napravimo ciklotron veličine Meseca onda će dokaza možda biti, za razliku od vernika koji ama baš nikad ne može da dođe do dokaza za svoje verovanje. Drugo, a što je posledica prvog, ovaj naučnik će odustati od svoje vere ako se dokaže da nije bio u pravu, za razliku od vernika kome dokazi ništa ne znače. Treće, postoji sijaset drugih naučnika sa raznim drugim teorijama, ali kad se stupi na domen empirijske provere onda postoji samo jedan "svet" u nauci, ovaj naš svet, za razliku od raznih religijskih grupacija koje prosto nemaju način usklade svoje sisteme, i koje nikad neće moći da imaju "jedan svet". I četvrto, od ovog teoretisanja može da ispadne nešto korisno, neki novi metod ili novi pristup širenju našeg znanja, čak i ako se pokaže da je sama teorija nevalidna. U religiji toga prosto nema, ne širi se znanje, nego samo verovanje. Religija ne može da predvidi buduće događaje, niti da objasni prirodne fenomene, i prilično je beskorisna, za sve osim za umirenje savesti.

Dobro, i drugo nešto je tu bitno istaći kao razliku između religije i nauke. Religija u centar stavlja istinu a nauka znanje. U religiji principijelno ne mogu da postoje dva istinita a oprečna iskaza u isto vreme (Kolakovski je odavno mudro ukazivao da pitanje "Ako je Bog apsolutno dobar a svemoćan, da li to znači da ima moć da čini zlo?" nema smisla jer je sve što Bog čini po definiciji dobro) dok je nauka naravno tu mnogo granularnija i istine generalno ograničava na definisane modele u kojima one važe i gde mogu biti upotrebljive. Već smo negde pominjali da planetarni model atoma nema zapravo veze sa "stvarnim" izgledom atoma ali da je na određenom nivou rasprave koristan - pa time i tačan - pa onda isto tako njutnovska i plankovska mehanika obe imaju jasne matematičke modele koji ih opisuju i obe su istinite u isto vreme a jedna drugoj su kontradiktorne. Dakle, nema smisla svoditi nauku na veru niti veru na nauku.

Hmmm...
Ja bih voleo da naidje naučnik koji može da mi dokaže nepostojanje Boga, kao i postojanje crnih rupa.
Ali nažalost...
E, meni moja religija ne brani da verujem da crne rupe postoje.
Ok, dokažite, važi,eto postoje.
I šta sad?
Da li one dokazuju da Bog ne postoji!?

Ne.
Najbitnije je to,što sve i da postoje i da su tačne i tralala, koji će nam moj to znanje!?

Mislim da je njima mesto u naučnoj fantastici, a ne u nauci, al' eto to je moje mišljenje.
Svejedno i da sad verujem da postoje, mac, evo, ti mi reci šta da radim sa tim saznanjem?
Štać'š ti da radiš?

Quote from: Meho Krljic on 23-02-2016, 11:43:30
Dobro, i drugo nešto je tu bitno istaći kao razliku između religije i nauke. Religija u centar stavlja istinu a nauka znanje. U religiji principijelno ne mogu da postoje dva istinita a oprečna iskaza u isto vreme (Kolakovski je odavno mudro ukazivao da pitanje "Ako je Bog apsolutno dobar a svemoćan, da li to znači da ima moć da čini zlo?" nema smisla jer je sve što Bog čini po definiciji dobro) dok je nauka naravno tu mnogo granularnija i istine generalno ograničava na definisane modele u kojima one važe i gde mogu biti upotrebljive. Već smo negde pominjali da planetarni model atoma nema zapravo veze sa "stvarnim" izgledom atoma ali da je na određenom nivou rasprave koristan - pa time i tačan - pa onda isto tako njutnovska i plankovska mehanika obe imaju jasne matematičke modele koji ih opisuju i obe su istinite u isto vreme a jedna drugoj su kontradiktorne. Dakle, nema smisla svoditi nauku na veru niti veru na nauku.

Da si s'ovakim žarom pis'o o kontracepciji, pare bi zaradio.....

Pa evo, da bismo mogli da otkrijemo gravitacione talase (koje su eto napravile dve crne rupe pred sudarom) morali smo da osmislimo potpuno novi instrument, koji ranije nismo imali jer nam nije ni trebao. Ali sad kad imamo tu novu vrstu instrumenta možemo da je iskoristimo za posmatranje drugih fenomena koji nemaju veze samo sa crnim rupama. Znanje se širi.

Za idealne solarne ćelije i idealne baterije verovatno će nam trebati upotrebljivo znanje iz kvantne fizike. Znanje se prepliće.

Za sada nemamo neku veliku upotrebnu vrednost baš od crnih rupa, osim što one velike koristimo kao gravitaciona sočiva da bismo videli udaljene galaksije koje se nalaze iza njih. Ali imamo koristi od mnogih drugih otkrića. Crne rupe su samo delić našeg znanja, koje se neprestano širi.

Polako s pare, zaradićemo. Samo sam udario u nekoliko nepredviđenih prepreka.  :lol:



Nego, nadam se da se nauka ne doživljava kao aktivnost koja treba da dokaže nepostojanje boga? U nauci ionako generalno stvari stoje tako da onaj ko nešto tvrdi to treba da dokaže, dakle, kada bi se nauka i bavila postojanjem boga, ona bi verovatnije išla na to da dokaže pretpostavku njegovog postojanja (kao što je Toma Akvinski i radio sa svojom Sumom Teologikom (http://www.sparknotes.com/philosophy/aquinas/section2.rhtml)). Drugim rečima, nauka obično ima pozitivističku filozofiju: pretpostaviš da nešto postoji ili funkcioniše na taj i taj način a onda tražiš način da to i potvrdiš na što je moguće objektivniji način.

U tom smislu su i crne rupe isprva bile koncept samo na papiru, sa fizičarima i matematičarima u osamnaestom veku koji su proučavali kako gravitacija funkcioniše pa pretpostavili njihovo postojanje na osnovu do tada poznatih (tj. dokazivih) činjenica o gravitacionoj sili i njenom uticaju na materiju i energiju. Kasnije smo dobili i opservacione potvrde da zaista ima nebeskih tela koja se ponašaju u skladu sa tim pretpostavljenim modelima itd. Da li danas iko tvrdi da znamo sve o njima i da smo ih potpuno opisali sa strane matematike i fizike? Ne, ali postoji relativno uverljiv model sa kojim se većina struke slaže. Pošto mi nismo struka, ostaje nam da struci verujemo ili ne verujemo, naravno, upućujući se u materiju koliko nam dopušta vreme i lenjost.

Ja je ne doživljavam, Darvinisti i još poneki da.
Ej, pa i ja se bavim naukom, proučavam crtanje, grafike, odnose crno-belog, razmišljam o bojama koje će tu doći ponekad, itd.
Moraš prvo da naučiš šta je masa pametnijih od tebe uradila, pa da nastaviš to da radiš.

U bibliji nema ništa naučiš od crtanje! ;)

Pa, dobro, jasno, svete knjige, pogotovo u današnje vreme, ne treba da budu izvor svog znanja, pogotovo ne u tim nekim praktičnim oblastima, već putokaz u duhovnost i moralna pitanja. I Kuran je danas u smislu praktičnih saveta prilično zastareo mada je u vreme kada se pojavio bio (između ostalog) bukvalno spisak instrukcija kako da se čovek ponaša da bi opstao kao jedinka i ojačao društvo - od nejednja potencijalno nehigijenskog mesa do lične higijene itd. E, sad, što mnogi i danas radije gledaju te površne elemente svetih spisa (dal' postiš po danu a jedeš samo između sumraka & svitanja, dal' pereš dupe il' koristiš toalet papir) a promiču im duhovniji sadržaji, to je, jebiga, tako, imamo suviše drugih razbibriga u životu da se ozbiljno posvetimo proučavanju vere...  :lol:

Stephen Hawking Suggests Black Holes Are Possible Portals To Another Universe (http://www.scienceworldreport.com/articles/38682/20160423/stephen-hawking-suggests-black-holes-possible-portals-another-universe.htm)

QuoteStephen Hawking, in a recent lecture held at the Harvard University, claimed that black holes could be portals to a parallel universe. The celebrated physicist spoke at length about black holes and suggested that they neither store materials absorbed by them nor physical information about the object that created them.


Known as the information paradox, the theory goes against the scientific rule that information on a system belonging to a particular time can be used to understand its state at a different time. Over the years, it has been speculated that black holes do not retain information about the stars from which they are formed, except storing their electrical charge, angular momentum and mass.
According to Hawking, as per that theory, it was believed that identical black holes might be formed by an infinite quantity of matter configurations. However, quantum mechanics has signaled the opposite by revealing that black holes could only be formed by particles with explicit wavelengths. If the characteristics of the bodies that create black holes are not deprived, then they include a lot of information that is not revealed to the outside world, according to the physicist.
"For more than 200 years, we have believed in the science of determinism, that is that the laws of science determine the evolution of the universe" Stephen Hawking said (http://news.harvard.edu/gazette/story/2016/04/hawking-at-harvard/).  If information was lost in black holes, we wouldn't be able to predict the future because the black hole could emit any collection of particles."
In an earlier talk (http://www.express.co.uk/news/science/662598/Stephen-Hawking-black-holes-space-science-Harvard), Hawking had said things can escape out a black hole, both from the outside and probably through another universe. Currently, Hawking and his colleagues are working on understanding "supertranslations" to offer an explanation for the mechanism via which information is returned from a black hole and encoded on its event horizon.

How Cold Are Black Holes? (http://www.universetoday.com/130605/cold-black-holes/) 

Quote
Today we're going to have the most surreal conversation. I'm going to struggle to explain it, and you're going to struggle to understand it. And only Stephen Hawking is going to really, truly, understand what's actually going on.
But that's fine, I'm sure he appreciates our feeble attempts to wrap our brains around this mind bending concept.
All right? Let's get to it. Black holes again. But this time, we're going to figure out their temperature.
The very idea that a black hole could have a temperature strains the imagination. I mean, how can something that absorbs all the matter and energy that falls into it have a temperature? When you feel the warmth of a toasty fireplace, you're really feeling the infrared photons radiating from the fire and surrounding metal or stone.
And black holes absorb all the energy falling into them. There is absolutely no infrared radiation coming from a black hole. No gamma radiation, no radio waves. Nothing gets out.

Now, supermassive black holes can shine with the energy of billions of stars, when they become quasars. When they're actively feeding on stars and clouds of gas and dust. This material piles up into an accretion disk around the black hole with such density that it acts like the core of a star, undergoing nuclear fusion.
But that's not the kind of temperature we're talking about. We're talking about the temperature of the black hole's event horizon, when it's not absorbing any material at all.
The temperature of black holes is connected to this whole concept of Hawking Radiation. The idea that over vast periods of time, black holes will generate virtual particles right at the edge of their event horizons. The most common kind of particles are photons, aka light, aka heat.
Normally these virtual particles are able to recombine and disappear in a puff of annihilation as quickly as they appear. But when a pair of these virtual particles appear right at the event horizon, one half of the pair drops into the black hole, while the other is free to escape into the Universe.
From your perspective as an outside observer, you see these particles escaping from the black hole. You see photons, and therefore, you can measure the temperature of the black hole.


The temperature of the black hole is inversely proportional to the mass of the black hole and the size of the event horizon. Think of it this way. Imagine the curved surface of a black hole's event horizon. There are many paths that a photon could try to take to get away from the event horizon, and the vast majority of those are paths that take it back down into the black hole's gravity well.
But for a few rare paths, when the photon is traveling perfectly perpendicular to the event horizon, then the photon has a chance to escape. The larger the event horizon, the less paths there are that a photon could take.
Since energy is being released into the Universe at the black hole's event horizon, but energy can neither be created or destroyed, the black hole itself provides the mass that supplies the energy to release these photons.
The black hole evaporates.
The most massive black holes in the Universe, the supermassive black holes with millions of times the math of the Sun will have a temperature of 1.4 x 10^-14 Kelvin. That's low. Almost absolute zero, but not quite.


A solar mass black hole might have a temperature of only .0.00000006 Kelvin. We're getting warmer.
Since these temperatures are much lower than the background temperature of the Universe – about 2.7 Kelvin, all the existing black holes will have an overall gain of mass. They're absorbing energy from the Cosmic Background Radiation faster than they're evaporating, and will for an incomprehensible amount of time into the future.
Until the background temperature of the Universe goes below the temperature of these black holes, they won't even start evaporating.
A black hole with the mass of the Earth is still too cold.
Only a black hole with about the mass of the Moon is warm enough to be evaporating faster than it's absorbing energy from the Universe.
As they get less massive, they get even hotter. A black hole with the mass of the asteroid Ceres would be 122 Kelvin. Still freezing, but getting warmer.
A black hole with half the mass of Vesta would blaze at more than 1,200 Kelvin. Now we're cooking!
Less massive, higher temperatures.
When black holes have lost most of their mass, they release the final material in a tremendous blast of energy, which should be visible to our telescopes.


Some astronomers are actively searching the night sky for blasts from black holes which were formed shortly after the Big Bang, when the Universe was hot and dense enough that black holes could just form.
It took them billions of years of evaporation to get to the point that they're starting to explode now.
This is just conjecture, though, no explosions have ever been linked to primordial black holes so far.
It's pretty crazy to think that an object that absorbs all energy that falls into it can also emit energy. Well, that's the Universe for you. Thanks for helping us figure it out Dr. Hawking.

https://youtu.be/LRtvGABJC2Q (https://youtu.be/LRtvGABJC2Q)

Ja i dalje ne verujem u postojanje crnih rupa...
...to za mene čista laž....
....a plus kad krenu još da ih opisuju i mere im temperaturu i ....
...ma zajeeeeeeeeeeBte..

Šta uopšte hoće ti astrofizičari? Da im verujemo na reč? Da naučimo fiziku? NEČUVENO!!!!!!!!!

Možda da prvo naučimo razliku između Fizike i Sajfaja?

Ali bio si u pravu u jednom od prethodnih postova, razlika između pranja i brisanja guzice i rasprave oko toga...

Bila bi divota da nas pojede crna rupa jer ne bi ni osetili, a postigli bi željeno.

Quote from: Ugly MF on 03-09-2016, 09:59:19
Ja i dalje ne verujem u postojanje crnih rupa...
...to za mene čista laž....
....a plus kad krenu još da ih opisuju i mere im temperaturu i ....
...ma zajeeeeeeeeeeBte..

A što buraz?

Pošto do sada nije rekao zašto ne veruje ja ću biti slobodan da mu inputujem. Bog postoji, i božja reč postoji, i nalazi se svuda, pa čak i u crnim rupama. Ali naučnici kažu da ono što je u crnoj rupi ne može da "izađe napolje", uključujući i Božju reč. To ne sme da bude, i u skladu s tim, crne rupe ne smeju da budu.

Па ђе се шаљу невјерници ако нема црних рупа?

Ne da ja ne verujem u postojanje crnih rupa, nego ne verujem još u masu stvari koje pričaju 'naučnici'.
Naravno, vera u Boga s' tim nema veze, ja ne vidim zašto bi se to pominjalo, dragi moj krivoverni mac, pričamo o crnim rupama.
Pošto ništa u vezi crnih rupa nije dokazano, nego samo teorije postoje, kako ja da verujem u njihovo postojanje?
I zašto bi?
I čemu one služe?
I čemu služi to znanje osim za divne sajfaj priče?

Ali koji dokaz bi nama bio dostatan? Postoje matematički modeli koji opisuju fenomene koji se ponavljaju i predviđaju buduće ponašanje. To bi trebalo da je solidan dokaz.

U redu je, imaš mogućnosti da ne veruješ do kraja sledeće godine (https://en.wikipedia.org/wiki/Event_Horizon_Telescope), a onda ćemo dobiti slike i pravi dokaz. Ono što sad imamo (http://www.skyandtelescope.com/astronomy-news/best-evidence-yet-that-black-holes-really-exist-0505201523/) jeste prilično uverljivo, ali za mnoge astrofizičare nije 100% dokaz. Za mene jeste, ali ja nisam astrofizičar.

U šta još ne veruješ, ako smem da pitam? Da li veruješ da je svemir star 13 milijardi godina, da je Zemlja stara 4.5 milijardi, a da je homo sapiens star 200 hiljada godina? Da li veruješ da je život oduvek menjao svoj oblik (nekakava evolucija, ne mora biti baš Darvinova), i da ga menja i sada? Da li veruješ da globalno zagrevanje postoji, i da ga je pritom izazavao čovek sagorevanjem uglja i nafte? Da li veruješ da se putanja svetlosti krivi pod uticajem gravitacije, a da je to objašnjeno Ajnštajnovom opštom teorijom relativnosti?

Postoje stvari koje nikad ne možeš da ZNAŠ, ali ni znanje nije najbitnije na svetu.
Ja VERUJEM u neke stvari koje nikada nisam video.
Tvoja pitanja su nebitna i ja lično , kao što NIKO na svetu NE ZNA odgovore možemo samo različito da VERUJEMO  u neke nama date informacije.
Ne verujem da je Zemlja stara 4.5, svemir 13 milkera, a Ljudi 200 000....eto.
Evolucija ne, degradacija da.
Globalno zagrevanje...phiii,,,baš me nešto briga,,,nebitno, al' ako treba baš da odgovorim, da eto, nek postoji, ali eto, ne sa emisijom gasova....mož' biti i nešto drugo, eto...
Objašnjena Ajnštajnovom teorijom,huh...?
Ništa laboratorije, jelte, opiti itd,,,tolki kurčevi Cernovi akceleratori, a ne dokazaše to, nego i dalje teorija...?
Mislim, tolku tehnologiju imamo baziranu na toj optici i laserima, da bi to trebao neko da zna ko se time bavi, a ne mene da pitaš....

...kao kad bi ja tebe pitao, veruješ li da me sad ovog momenta svrbi levo ili desno jaje...i dal' sam ga počešao?

Quote from: tomat on 03-09-2016, 18:41:08

Quote from: Ugly MF on 03-09-2016, 09:59:19
Ja i dalje ne verujem u postojanje crnih rupa...
...to za mene čista laž....
....a plus kad krenu još da ih opisuju i mere im temperaturu i ....
...ma zajeeeeeeeeeeBte..

A što buraz?

Ajde, bre, pa nisam samo ja, eno na macovim linkovima još neki astrofizičari ne veruju, ima nas još takvih, nisam samo ja.....pitaj njih, oni bolje znaju....

Глобално загријавање изазива црне рупе!

Postoji fundamentalna razlika između teorije i zakona, i ne treba mešati ta dva pojma. Naučna teorija je hipoteza potvrđena eksperimentima do te mere da se usvaja kao objašnjenje nekog fenomena. Naučni zakon je matematički razrađena činjenica o svetu koji nas okružuje. Teorija nikad neće postati zakon jer su to dve različite stvari. Zakon ne objašnjava pojavu nego omogućava da matematički modeliramo pojavu. Teorija daje objašnjenje pojave. Pogledaj video.

https://www.youtube.com/watch?v=lqk3TKuGNBA (https://www.youtube.com/watch?v=lqk3TKuGNBA)

Uzgred, pošto ne veruješ u iste opšte prihvaćene naučne teorije u koje ne veruju ni kreacionisti moram da zaključim da ti je Biblija preča od naučnog saznanja. Možeš da poričeš koliko te je volja da vera u Boga ima s tim veze, ali što bi rekao petao Sofronije, cifre ne lažu. Pošto ti je Biblija preča od naučnog saznanja onda sa naučnog stanovišta više nije bitno u šta veruješ ili ne veruješ. Saznanje ti nije prioritet, dakle nisi iz te priče.

Цифре нису лагале ни Питагору и Платона онда када су тражили неке креационистичке елементе помоћу математике, која је иначе настала у религијским и езотеричним круговима, и као таква се развијала хиљадама година. Хтједох рећи, не прави бога од цифре.

Агли здраворазумски прилази проблему, не вјерује ни да је Земља округла зато што неко има слику Земље. Можда је монтажа!

Jeste da se čovek hvata za reč, ali uhvatio si me sa pogrešne strane. "Cifre ne lažu" se odnosi na moje uverenje da je Ugliju Biblija preča od saznanja. Možda bi bilo jasnije da sam rekao "rog ne laže".

Само под условом да је Библија коза а математика рог. Јер та наука јесте створена од стране свештеника, и врло је занимљиво како од ренесансе поштују рог али не и козу, и уопште не сумњају у рог али сумњају у козу.

Математика је људска творевина, некад није имала нулу ни негативне ни арапске бројеве ни интеграле, кубове итд... дакле, ко зна шта сад нема и шта ће тек имати.

Кад се докаже доказало се, нема потребе трчати пред руду, историја је показала да је Галилејов доказ био нетачан, па опет и данас тврде да је он у праву а црква је гријешила. А прави доказ Галилејове тврдње нашао је Кеплер 200 година касније.

U svoj toj tvojoj priči, ti mi ne odgovori koje me je jaje svrbelo, mac...

Znaš, za nekog koga tačno zabole za crne rupe, ni meni nije jasno šta ću ja na ovom ovde topiku, al' ajde...
Nešto me živo zanima, mac i tomat, dva velika znalca ovde, verujete li u to da je planeta prenaseljena?

tl;dr: Ne

Postoje dva stanovišta. Jedno je da planeta nikad ne može biti "prenaseljena" su smislu da će uvek postojati neki ljudi kojima trenutno stanje ne smeta. Drugo stanovište je da planeta odavno prenaseljena jer su oduvek postojali neki ljudi kojima trenutno stanje smeta.

Pokušaj spajanja ova dva stanovišta je da možemo reći da planeta postaje "prenaseljenija" ako se vremenom menja odnos ovih brojeva. Da li se trenutno menja odnos ovih brojeva? Da, ali u korist onih kojima ne smeta.

Ne razumem šta pokušavaš da izigravaš?
Satelit, antenu, refleksiju nekih drugih koje smatraš superiornijim od sebe, pa u dve rečenice pokušavaš da objasniš NJIMA kolko si i ti pametan, zamotavajući govno u mirišljavi papir i
proglašavajući time sebe dostojnih trgovaca kao što su oni.Iako jedino ogledalo vidi tvoje 'uspehe' a ne iko od njih.

Alo, oćemo prostački, brate, da te svi razumeju, š'a ti meni ovo-ono, jedno,dva stanovišta, mangupe?

Pito sam te ,bre, za tvoje mišljenje,
ALO, eeeeee,,, TVOJE,,,,eeeeee,,,
šta Ti veruješ, ili znaš, eeee....

Ti mi mrsomudiš neka stanovištva, ...
PIČKO jedna!

...ili te to Boban upozorio da ako javno izneseš svoje mišljenje, možeš biti izvrgnut ruglu i podsmehu na ovom forumu, ....hahaaaaaa...

koji si ti jad i beda i mizerija, bez mudiju da se izjasni....

e, bajdvej, Bog je rekao da se ljudi trebaju množiti i napuniti zemlju,znaš!?
Tako da ti ja objasnim, pošto ti izgleda pojma nemaš, nikad neće biti prenaseljenosti!
Eto, veruj mi, pomogao sam ti u životu s' ovim!

 :shock: Pa, napisao ti je jasno "NE" u prvom redu. A sad čovek ispade pička što je to i obrazložio...  :cry: :cry: :cry:

Nekad mi se čini da postoji više verzija srpskog jezika, i da se zato loše sporazumevam s nekim ljudima. Prosto pričamo različitim verzijama.


Znači, odgovor je "ne, Zemlja trenutno nije prenaseljena, prosto zato što nas stalno ima više". Onog trenutka kad prestane da nas ima više (tj. kad populacioni rast padne na nulu) moj odgovor će se promenti u "da, sad je Zemlja prenaseljena, prosto zato što je populacija procenila da nema više mesta za nove ljude".


Da primenim Čika Jovin opis dizanja ustanka u Srbiji: još nije vreme, još nije vreme, još nije vreme... E sad je dockan!


Pravo pitanje nije da li je Zemlja prenaseljena, nego da li trenutni menadžment resursima može našim potomcima da stvori neke probleme. Recimo kad potrošimo sav plutonijum na Zemlji, i kad više ne budemo bili u stanju da nabavimo novi plutonijum, kako ćemo da napajamo svemirska plovila? Daleko od Sunca slabe su vajde od solarnih ćelija.

Pa zar nije ono prvo ne bilo too long not read, vezano za češanje mojih jajca!?!?

Ahm...
Dobro.
Ajd onda, svrab mojih jaja i postojanje crnih rupa u jednu košaricu,
i zaboravimo to.
I izgleda da treba da jasnije odgovaraš, majke mi, ne samo lupiš ne, pa završimo u nesporazumima.

A što se tiče zemljanih resursa, mi ionako i dan danas ne raspodeljujemo stvari kako treba, i nikad i nećemo.

A iskreno me obradovao odgovor NE, jer sam očekivao ispran mozak sveckih medija koji ne zna se čime više drukaju, dal ' crnim rupama, dal' globalnim zagrevanjem, dal' prenaseljenošću.

Samo sledeći put konkretnije i razumnije naglasi , ko što ja detaljno naglasim kad kome gde i zašto.

Mda, pričao sam o nerazumevanju srpskog, a problem je bio u tl;dr. Elem, tl;dr se koristi da se ispred dugog teksta stavi kratki tekst za one koje mrzi da čitaju dugi tekst. Dva teksta (kratki i dugi) moraju zato da imaju istu poruku. Kod mene je poruka data u poslednjoj rečenici "dugog teksta": odnos brojeva onih kojima ne smeta i kojima smeta trenutna naseljenost raste u korist onih kojima ne smeta, prema tome Zemlja još nije dovoljno prenaseljena. Treba je još prenaseliti :)

A naravno da se nisam osvrtao na svrab tvojih jaja na temi o crnim rupama. Cenim da to pitanje više pripada temi o vicevima, "zašto majmun pere jaja u mom viskiju"...

Uzgred, imamo i lepe vesti u vezi s plutonijumom. Amerika od ove godine ponovo proizvodi (http://www.space.com/31499-us-makes-plutonium-deep-space-fuel.html) odgovarajući plutonijum-238, specijalno za potrebe istraživanja svemira.

Baah...nikada ništa mi tamo nećemo naći, problem je što tolko pameti, kalkulacije, fizike i štatijaznam čega, izvuče pare da se zazidaju nekakvi akceleratori de ti isti fizičari vrše satanske obrede, umesto da su naranili sirotinju u Africi , ane testirali Ziku na njima....

Inače, u Jordanu se gradi akcelerator čestica, a u izgradnji učestvuju (između ostalih) Jordan, Iran, Egipat, Pakistan, Izrael, Palestina,...

https://www.theguardian.com/world/2016/aug/30/sesame-particle-accelerator-project-middle-east-jordan

Dakle, što religija razjedini, fizika ujedini :lol:

It's official: You're lost in a directionless universe (http://www.sciencemag.org/news/2016/09/it-s-official-you-re-lost-directionless-universe) 

Quote
Ever peer into the night sky and wonder whether space is really the same in all directions or whether the cosmos might be whirling about like a vast top? Now, one team of cosmologists has used the oldest radiation there is, the afterglow of the big bang, or the cosmic microwave background (CMB), to show that the universe is "isotropic," or the same no matter which way you look: There is no spin axis or any other special direction in space. In fact, they estimate that there is only a one-in-121,000 chance of a preferred direction—the best evidence yet for an isotropic universe. That finding should provide some comfort for cosmologists, whose standard model of the evolution of the universe rests on an assumption of such uniformity.
"It's a much more comprehensive analysis than in previous cases," says Anthony Challinor, a cosmologist at the University of Cambridge in the United Kingdom who was not involved in the work. "The question of how isotropic is the universe is of fundamental importance."
In 1543, Nicolaus Copernicus knocked Earth and humanity from the supposed center of the universe by noting that Earth goes around the sun, not the other way around. That observation gave birth to the Copernican principle, which holds that we have no special place in the infinite, centerless universe. In the early 20th century, with the advent of Albert Einstein's general theory of relativity and the observation that the universe is expanding in all directions, that idea evolved into the cosmological principle, which assumes that the universe is the same everywhere and in every direction. In fancier terms, the universe is both homogeneous and isotropic.
The principle has its limitations. As the existence of stars and galaxies shows, matter is not distributed exactly the same way everywhere. This, they assume, arises because the universe was born as a homogeneous soup of subatomic particles in the big bang. As the universe underwent an exponential growth spurt called inflation, tiny quantum fluctuations in that soup expanded to gargantuan sizes, providing density variations that would seed the galaxies. Yet, the standard model of cosmology rests on the assumption that, on the largest scales, these variations are insignificant, and space is homogeneous and isotropic.
But it doesn't necessarily have to be that way. Theoretically, it's possible that space could be the same from point to point, but still have special directions—much as a diamond crystal has uniform density, but specific directions in which its atoms line up in rows. There were even some hints of such "anisotropy" in the early 2000s, when measurements from NASA's Wilkinson Microwave Anisotropy Probe (WMAP) spacecraft suggested that some subtle undulations in the motley CMB appeared to line up along a so-called "axis of evil" (http://science.sciencemag.org/content/317/5846/1848)—which most researchers discount as a statistical fluke.
Now, Daniela Saadeh and Andrew Pontzen, cosmologists at University College London, and colleagues have ruled out special directions with the most stringent test yet. They also use measurements of the CMB, this time taken with the European Space Agency's Planck spacecraft, which collected data from 2009 to 2013 and provided far more precise CMB maps than WMAP. Instead of looking for curious imbalances in the CMB, they systematically worked the other way around. They considered all the ways that space could have a preferred direction and how such scenarios might imprint themselves on the CMB. Then they searched for those specific signs in the data.

For example, space could be expanding at different speeds along different axes. Such differential expansion would cause the radiation from some directions to stretch to longer wavelengths than in others, and the upshot would be a big bull's-eye pattern in the CMB. Or, space could be rotating about a particular axis, which would create a spiral pattern in the CMB. Finally, the newborn universe could have been agitated by distortions in space itself known as gravitational waves, which would stretch the whole cosmos in one direction and compress it in a perpendicular direction. That sort of motion would leave more complex spirals in the CMB. In all, the researchers identify five potential patterns or "modes" in the CMB that would signal some sort of special direction in space.
Using a supercomputer, Saadeh, Pontzen, and colleagues look for evidence of any such patterns lurking faintly behind random variations in the CMB's temperature—a process not unlike trying to pick out a weak picture through extreme static on an old-fashioned TV screen. To give their study even more bite, they also look for accompanying patterns in the polarization of the CMB's microwaves, which Planck also mapped. For three of the five patterns, "polarization data is the killer thing," Saadeh says.
Others had performed similar tests for signs that the universe is spinning, but Saadeh, Pontzen, and colleagues improve the limit on such a signal by an order of magnitude. They also put limits on all other kinds of anisotropy (http://arxiv.org/abs/1605.07178), as they report in a paper in press at Physical Review Letters. "For the first time, we really exclude anisotropy," Saadeh says. "Before, it was only that it hadn't been probed."
But just how significant is that advance? That's hard to judge, Challinor says, because there aren't compelling alternatives to the standard model of cosmology that predict exactly how an anisotropic universe should be. "The problem is, what do you compare it to?" he asks. Still, he notes, "this assumption is fundamental cosmology" so "it's very important to check."

The Big Bang Wasn't The Beginning, After All (https://www.forbes.com/sites/startswithabang/2017/09/21/the-big-bang-wasnt-the-beginning-after-all/#74351a9e55df)

Jel' samo ja smatram ovaj članak za totalnu fabrikaciju 'nauke' o kojoj oni govore ili ima još neko normalan ovde?
Misliiiim, tolke mlatke, jedva živi ostanu i nikom ništa?!?
Kakav bre big bang i planete?
To ne postoji, kakav bre univerzum 'with billions and billions...'

Karl Segan, gledaćemo se oči u oči na onom svetu, kad tad!

Most Powerful Cosmic Rays Come from Galaxies Far, Far Away (https://www.space.com/38223-powerful-cosmic-rays-galaxy-far-away.html)

Scientists record a fourth set of gravitational waves (https://www.engadget.com/2017/09/27/scientists-record-fourth-set-gravitational-waves/)

Znamo šta Beteridžov zakon naslova kaže, ali opet, Itan Sigel se trudi da nas razgali spekulacijama:


Are Space, Time, And Gravity All Just Illusions? (https://www.forbes.com/sites/startswithabang/2017/10/04/are-space-time-and-gravity-all-just-illusions/#24344b6e41cf)

Found: The most distant supermassive black hole ever observed  (https://www.eurekalert.org/pub_releases/2017-12/cifs-ftm120517.php)

https://bigthink.com/starts-with-a-bang/singularities-dont-exist-roy-kerr/ (https://bigthink.com/starts-with-a-bang/singularities-dont-exist-roy-kerr/)

Čiča Kerr je kurčevit i u 89. godini, ima dole link na ceo rad pa bacite oko na apstrakt kad opljune po Penrouzu i Hokingu :lol:

Rad, a bome ni članak, nisu kežual čitanje, al ko voli da malo lomi mozak evo izvolte.