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Black Holes Not Black After All, Theorize Physicists
KentuckyFC (1144503) writes Black holes are singularities in spacetime formed by stars that have collapsed at the end of their lives. But while black holes are one of the best known ideas in cosmology, physicists have never been entirely comfortable with the idea that regions of the universe can become infinitely dense. Indeed, they only accept this because they can't think of any reason why it shouldn't happen. But in the last few months, just such a reason has emerged as a result of intense debate about one of cosmology's greatest problems — the information paradox. This is the fundamental tenet in quantum mechanics that all the information about a system is encoded in its wave function and this always evolves in a way that conserves information. The paradox arises when this system falls into a black hole causing the information to devolve into a single state. So information must be lost.
Earlier this year, Stephen Hawking proposed a solution. His idea is that gravitational collapse can never continue beyond the so-called event horizon of a black hole beyond which information is lost. Gravitational collapse would approach the boundary but never go beyond it. That solves the information paradox but raises another question instead: if not a black hole, then what? Now one physicist has worked out the answer. His conclusion is that the collapsed star should end up about twice the radius of a conventional black hole but would not be dense enough to trap light forever and therefore would not be black. Indeed, to all intents and purposes, it would look like a large neutron star.
Earlier this year, Stephen Hawking proposed a solution. His idea is that gravitational collapse can never continue beyond the so-called event horizon of a black hole beyond which information is lost. Gravitational collapse would approach the boundary but never go beyond it. That solves the information paradox but raises another question instead: if not a black hole, then what? Now one physicist has worked out the answer. His conclusion is that the collapsed star should end up about twice the radius of a conventional black hole but would not be dense enough to trap light forever and therefore would not be black. Indeed, to all intents and purposes, it would look like a large neutron star.
Or just not quite as dense as we thought.
You're looking for quotes? See my journal.
Frozen Star by George Greenstein had as a central theme that due to gravitational time dilation that we could never see a star collapse beyond its own event horizon: it would asymptotically approach it as arbitrarily close as we liked given unlimited time but never cross it. So as a natural consequence there was always a tiny but measurable probability that trapped light and thus information could escape.
Although this is a layperson's work, it is based on his published papers which provide a mathematical background.
-- Insert witty one-liner here. --
physicists have never been entirely comfortable with the idea that regions of the universe can become infinitely density
I'm pretty sure that editors outside of /. have never been entirely comfortable with that idea either.
Ezekiel 23:20
Orange is the new black...hole...
"He's lost in a 'floyd hole"
physicists have never been entirely comfortable with the idea that regions of the universe can become infinitely density.
Infinitely density. Wow. The Engrish need helped.
I know that Black Holes aren't supposed to be observable - but I thought there were observations of other things, such as things being eaten by black holes and the interactions between a black hole's massive gravity well and the environment around it. If this study is right, shouldn't the astrophysicists who first observed the by-products of black holes have been able to see them?
following the convention for naming stars that are not dense enough to ignite "brown dwarfs", we could name these new, less dense, singularities... "brown holes".
Now how is Michio Kaku going to portray black holes as marauding monsters that travel around like itinerant serial killers, gobbling up everything in their path?
Black holes aren't "infinitely dense" because that is ridiculous
"When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
After I read TFS, I am become infinitely hilarity!
"When information is power, privacy is freedom" - Jah-Wren Ryel
WTF does a large neutron star look like then?
Lost at C:>. Found at C.
Holy crap. The referenced paper is dense enough to have its own Schwarzschild radius.
physicists have never been entirely comfortable with the idea that regions of the universe can become infinitely density.
They've clearly never been to DC. I'm convinced that regions of the universe are infinitely dense.
Slow down, cowboy! It has been 4 hours since you last posted. You must wait another few hours.
Or... maybe it doesn't devolve into a single state at all. We can't actually see what goes on inside of black hole... but if our assumptions about what actually happens appear to create a paradox, then maybe it's our assumptions aren't valid, rather than the original basic concept of what a black hole supposedly is. I believe that the concept that black holes are necessarily singularities may be flawed. Space is so distorted by gravity in their vicinity that straight lines which intersect their event horizon never exit it, but I do not think that means that all of a black hole's mass is necessarily at its center, or even necessarily collapsing inexorably towards its center. Its center is just its center of mass.
And yeah, I know that astrophysicists with a vastly more qualifications than I have came up with these ideas, but in the end, an argument from authority does not make one actually right.
File under 'M' for 'Manic ranting'
What you say! These is much English goodly!
IIRC, string theorists have also proposed the idea that there are no singularities. In their model, the gravitational collapse of a star of sufficient mass causes all the strings of its component particles to coalesce into one highly-energetic string, sort of a super-particle. The information content of the original matter would be preserved in the vibration pattern of the final string.
Koans and fables for the software engineer
No, you are dead wrong, completely and utterly wrong. "For all intents and purposes" has been down-grammaticised into "for all intensive purposes". The latter has no actual meaning.
char*f="char*f=%c%s%c;main(){printf(f,34,f,34);}";main(){printf(f,34,f,34);}
A lot of phenomena in astrophysics are ridiculous, but real.
NB: The message above might reflect my opinion right now, but not necessarily tomorrow or next year.
Infinity and infinitesimals are abstract concepts. They do not occur in reality by their very definition as neither can ever be reached.
Not quite, they're building it on presumption.
"For all intents and purposes" has been down-grammaticised into "for all intensive purposes". The latter has no actual meaning.
That is untrue! For all intensive purposes i use an exercise machine!
This Space Intentionally Left Blank
1) Information is another term for entropy.
2) Thermodynamic says that potential energy and entropy are inversely proportional in an isolated system.
3) Thermodynamics furthers says that the entropy of an isolated system always increases until it reaches a minimum potential energy state. Why? If the entropy of a system decreases, that implies that potential energy is increasing. But if it's an isolated system, where did that potential energy come from?
Because black holes exist within an isolated system that is the universe, if they were able to decrease the entropy of the universe then that would imply that they're generating potential energy. Remember that capacity for work is the same as potential energy, so black holes would then be the equivalent of perpetual motion machines because the expenditure of potential energy (i.e. work) creates more entropy, which would be swallowed by a black hole, which would generate more potential energy, ad infinitum. That state of affairs just wouldn't seem to mirror our larger understanding of the universe.
Also, consider that what we call "time" is effectively the same as an increase in entropy. That is, the universe is evolving to a minimum potential energy state, which is the same as "aging". If you could decrease entropy you'd effectively be making time go backward.
Of course, all this is premised on our definition of information, entropy, potential energy, etc. But as far as we know they're extremely solid and coherent concepts, and it makes more sense that some supposed phenomenon which violates that model is more likely to be false than those concepts are.
Anyhow, I'm not a physicist. I don't even play one on TV. I hope real physicists correct my mistakes.
Since no one has actually peeked inside of a black hole we really can't tell for certain.
What we do know is that when we do the math on our models what we find are things approaching infinity. Sometimes these are just caused by using the wrong coordinate system, but other times when we change coordinate systems, the singularity still exists.
It's important to note that when speaking about infinity don't fall into the fallacy of treating it as a value. You cannot have an infinite amount of something, but you can have something which has infinite characteristics. Consider Hilbert's Hotel which is an example of the hilarity found when trying to add finite numbers and infinity together. The expression " + 1" is meaningless because you can't add a value to infinity any more than you can add "a + 1".
What's actually happening in Hilbert's Hotel is the addition of aleph numbers with finite numbers, which you can do, but has silly results. Aleph-0 + 1 = Aleph-0. But this just describes the extent of the set, suppose we took a sum and looked at it:
1 + 2 + 3 + ... n + 1 = 2 + 2 + 3 + ... n
And no matter what you try to do with it, that extra one is still hiding in the sum. If you take this new set and subtract it by all of the natural numbers, you should be left with the result of 1. One of the most irritating things is when people say you can do things like you can in Hilbert's Hotel, writing it off like it's some quirk of infinity. But it's not. If you shifted all of the guests over to only even rooms, you would still have the same number of guests and rooms.
2((n) n) = 2 + 4 + 6 + ... 2n
You've effectively just doubled the number of rooms. It's a sleight of hand that breaks the rules. "But!" you may say, "You have infinite many rooms, so of course you have a room at 2n!" If you do think this then you're still caught up thinking about infinity as a literal value. You don't have a room at 2n, your rooms only extend to n, and now half of your guests (which is still an infinite many) don't have rooms, but are left to stand out in an endless hallway.
In essence, one kind of infinity does not necessarily equal another kind. /rant
>A lot of phenomena in astrophysics are ridiculous, but real.
No there are many ideas in astrophysics. We don't know if they are real.
Dark matter? Maybe or maybe not. Dark energy? Maybe or maybe not.
Hawking radiation? It is an idea, it hasn't been proven or disproven.
Speed of light limitation? Probably, but how are neutrinos that have mass going 99.9999% the speed of light? That should require almost infinite energy shouldn't it?
Big bang? A large body of evidence points to a time limit to the beginning of the universe, but cosmic background radiation is the only stronger evidence of a big bang --- yet this could have another explanation.
Cosmic inflation? Could be a non-starter for reasons we currently don't have a handle on --- case in point, it is only happening *far away*. Supernova are used as standard candles, but what if we had different looking supernova 10 billion years ago and our measurements are wrong, therefore inflation isn't happening.
Astrophysics is an emerging field, even now. There are few ways to test all the ideas.
Many of the theories of the exotic blackholes rest precariously on a shaky house of cards, because there is no convenient way to test the ideas.
Priest: "Universe from nothing, no laws of physics, sped up time"+ huge discrepancies. Creationism? No. Big Bang Theory
can some explain why information can't be lost? this is slightly confusing and that assumption makes it seem like they're building a lot of theory on a pretty shaky foundation.
It's actually not as mind bending as you might think.
Quantum mechanics is "Time Symmetrical" meaning that, the laws of physics work the same irrelevant of the direction of time.
This is only at the quantum scale so real world stuff doesn't work so hot.
But take a quantum particle falling into a blackhole...
If the blackhole consumed it, destroying all information about it... if you reversed time, the particle would never exist, and never be ejected back into space.
If, however, time slows as it approached the blackhole and the particle never actually crossed the event horizon... then if you reverse time, time would speed up and the particle would eventually be flung away.
This all depends on you accepting the standard model, and the current interpenetration of quantum physics. They are becoming more rock solid every day however, it would take some pretty amazing discoveries to break them.
I'm a professional mathematician and instructor and usually only lurk, but I feel obliged to say this -- you sound like you read a Wikipedia article, poorly, and I advise fellow ./ers not to take this post about Hilbert's hotel seriously.
None of the results are silly. They are all a logical consequence of the axioms of the system. Human beings are quite good a reasoning about finite situations (finitely many objects and finitely many operations on those objects), but humans are regularly surprised by results in situations where there are infinitely many objects or operations. You or anyone else being surprised by the results does not constitute the results silly. A more appropriate emotional response would be to find them interesting or beautiful, if it possible for any emotional response at all to be appropriate. The fact that you find them silly leads me to believe you fear the results, due to your misunderstanding of them.
For the interested ./er, if you really want to understand Hilbert's hotel you need to understand how mathematicians count things. A place to start is:
http://en.wikipedia.org/wiki/Cardinality
http://en.wikipedia.org/wiki/Bijection
(Wikipedia, I know.)
Yeah, well... your MOM is infinitely dense.
Yours is not infinitely dense. After all, everyone penetrates her.
"Flyin' in just a sweet place,
Never been known to fail..."
Some people are quite dense, though...
What if ONLY infinities exist? After all, what could lie outside them?
In fact, there'd be only "Infinity" all sense of plural or singular being reduced to non-statements.
Wow.
Have you ever REALLY looked at your fingernails, man?
"Flyin' in just a sweet place,
Never been known to fail..."
All Godel proved was that the Continuum Hypothesis could not be proven or disproven in Set Theory. Zeno presented a logical consequence if reality was a continuum, and the Effect proves the consequence actually exists. He just thought he was being clever because basic observation contradicts the logic, and to many proved continuum was not how space and time worked. However, there is evidence that no only he was right, but that it could very well be a continuum.
Who says I was talking about a planar triangle? http://en.wikipedia.org/wiki/S... :-p
Ok, I was... but the oldest geometry typo since the pyramids does not invalidate relativity.
Define a circle.
Do circles exist in reality, or only in mathematical models?
What do engineering artifacts, as approximations of circles, bear in relation to "real" circles?
Are infinities actual, or are they mathematical descriptions for mental extrapolations based in observed phenomena?
Do mathematical models display consistency with real, observable phenomena or with any mental extrapolation? Which one is more "real"? Why?
Mathematics can only describe the set of perceptions, IMHO. When they describe unperceived "realities" they enter the realm of fictions or metaphysics.
"Flyin' in just a sweet place,
Never been known to fail..."
Hand me the circle you say "exists". :-)
"Flyin' in just a sweet place,
Never been known to fail..."
Why is everyone so uncomfortable with the idea that something can be lost forever?
Because no one has figured out how to get the equations of quantum mechanics to work in only one direction without breaking them. And those equations are on really solid ground at this point, or your CPU wouldn't work.
If we're exceptionally lucky, rationalizing quantum mechanics and general relativity will finally reveal what time is and why everything in the universe appears to only proceed in one 'direction' in time. Don't hold your breath though. It's going to take a very strange kind of mind to figure that out, and such minds that are still in contact with reality are difficult to come by.
It just strikes me as fatuous and arrogant that humans think the universe has to work a certain rational, logical, way...
The equations of quantum mechanics work really well. The equations of relativity work really well. Plug either into the other and you get nonsense.
Anybody paying attention could conclude the universe doesn't work in a certain rational logical way.