From Nature: Black holes 'do not exist'
1 Apr 2005 11:29:33 UTC
Topic 188834
(moderation:
From Nature:
Black holes 'do not exist'
Black holes are staples of science fiction and many think astronomers have observed them indirectly. But according to a physicist at the Lawrence Livermore National Laboratory in California, these awesome breaches in space-time do not and indeed cannot exist.
In reference to this article:
DARK ENERGY STARS
Event horizons and closed time-like curves cannot exist in the real world for the simple reason that they are inconsistent with
quantum mechanics. Following ideas originated by Robert Laughlin, Pawel Mazur, Emil Mottola, David Santiago, and the
speaker it is now possible to describe in some detail what happens physically when one approaches and crosses a region of
space-time where classical general relativity predicts there should be an infinite red shift surface. This quantum critical physics
provides a new perspective on a variety of enigmatic astrophysical phenomena including supernovae explosions, gamma ray
bursts, positron emission, and dark matter.,
Grüße vom Sänger
From Nature: Black holes 'do not exist'
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>Event horizons and closed time-like curves cannot exist in the real world for the >simple reason that they are inconsistent with
>quantum mechanics
But yet they do exist. Could that possibly mean that the current quantum mechanics theory is flawed???? Hmmmmmmmmmmmmm. :-)
Well, like it was originally
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Well, like it was originally stated, well have never directly observed a black hole, but we have very good indirect evidence.
The biggest flaw is the assumption he makes here:
"The picture of gravitational collapse provided by classical general relativity cannot be physically correct because it conflicts with ordinary quantum mechanics."
The fact that there is an inconsistency is only proof that we don't understand everything about the subjects. The problem is just as likley to be a misunderstanding of QM as it is to be relativity (or maybe a little of both). We know we don't know everything about either subject, so why lock in what we do know as being the full picture and then eliminate anything that doesn't fit.
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I agree 1000%
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I agree 1000%
This is not as inconsistent
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This is not as inconsistent as it sounds.
When we 'see' a black hole, what we are looking at is light that left objects shortly before they fell through the event horizon. Obviously so, as once they fall through we cannot see them.
In addition, the closer the object gets to the event horizon, the longer it takes to get there, as observed by someone who keeps at a safe distance.
So for both these reasons, what we actuially see is a cloud of gas close to the event horizon, any one idenitifuable feature getting more and mor red-shifted as we continue to look, but never appearing to cross the event horizon from our point of view safely on the outside. I am told (maybe someone here will confirm or correct me) that in French an alternative name for a black hole is a 'stuck star', as it looks like a start that started to collapse but then got stuck in the process.
The outcome of all this is that it is very hard to tell the difference between the incredibly dense layer of accreting matter just outside the event horizon (as predicted by General Relativity) and the incredibly dense layer of accreted matter justy outside where the event horizon would be if we were allowed to have one (as predicted by some versions of quantum gravity). What we have seen so far is totally consistent with either explanation.
Would we even bother to change the name?
When Hawking showed that quantum effect let them shine a lttle after all we still went on calling them 'black'. If it does turn out that they are not holes either, I guess that would not mean we'd change the name, we'd just end up with a catchy name that is doubly inaccurate. Not black and not a hole either...
If you say that is unscientific, well we do that every time we refer to the effect popularly (but inaccurately) known as sunrise. A name that dates back to a now defunct scientific description of that well known daily event...
gravywavy~~
~~gravywavy
That IS a very interesting
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That IS a very interesting article and it is plausible...
This was interesting:
"He also thinks that the Universe could be filled with 'primordial' dark-energy stars. These are formed not by stellar collapse but by fluctuations of space-time itself, like blobs of liquid condensing spontaneously out of a cooling gas. These, he suggests, could be stuff that has the same gravitational effect as normal matter, but cannot be seen: the elusive substance known as dark matter."
> That IS a very interesting
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> That IS a very interesting article and it is plausible...
>
> This was interesting:
>
> "He also thinks that the Universe could be filled with 'primordial'
> dark-energy stars. These are formed not by stellar collapse but by
> fluctuations of space-time itself, like blobs of liquid condensing
> spontaneously out of a cooling gas. These, he suggests, could be stuff that
> has the same gravitational effect as normal matter, but cannot be seen: the
> elusive substance known as dark matter."
>
>
As for this idea I would have to stand middle ground. Now there may be "dark energy stars" but to discount a black hole is in my opinion idiotic. Looking carefully one can almost see the ripples from the big-bang. Matter or "dark-energy" could have formed bands just like matter has formed in bands in space. Both theories seem plausible. Why cant both exist?
WARNING! DiHydrogen MonOxide kills!
> but to discount a black
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> but to discount a black hole is in my opinion idiotic.
Nah having in mind that black holes are beyong event horizon as seen from our side then in fact it can be said that they do not exist for us :)
One quesiton I have is how do
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One quesiton I have is how do black holes grow? From the perspective of the distant observer, it takes infinately long for anything to actually cross the event horizon and "enter" the black hole. So, how do we end up with super-massive black holes at the centers of galaxies? Shouldn't they have taken an infinite amount of time to grow?
and an Artikel from
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and an Artikel from Space.com
BREAKING NEWS: Creation of Black Hole Detected Today
Astronomers photographed a cosmic event this morning which they believe is the birth of a black hole, SPACE.com has learned.
A faint visible-light flash moments after a high-energy gamma-ray burst likely heralds the merger of two dense neutron stars to create a relatively low-mass black hole, said Neil Gehrels of NASA's Goddard Space Flight Center. It is the first time an optical counterpart to a very short-duration gamma-ray burst has ever been detected.
Gamma rays are the most energetic form of radiation on the electromagnetic spectrum, which also includes X-rays, light and radio waves.
The merger occurred 2.2 billion light-years away, so it actually took place 2.2 billion years ago and the light just reached Earth this morning.
...
only for Info
Greetings from Germany NRW
Ulli
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One quesiton I have is how do
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One quesiton I have is how do black holes grow? From the perspective of the distant observer, it takes infinately long for anything to actually cross the event horizon and "enter" the black hole. So, how do we end up with super-massive black holes at the centers of galaxies? Shouldn't they have taken an infinite amount of time to grow?
The infinite time pradox you mention come from the static solutions for isolated bodies ie the black holes can not change. If the black hole is allowed to change then it evolves in finite time for distant observers.