On 9/25/2014 6:06 PM, LizR wrote:
On 26 September 2014 08:42, meekerdb <meeke...@verizon.net
<mailto:meeke...@verizon.net>> wrote:
The singularity is an inference from general relativity extrapolated to
arbitrarily
short distances and high densities...where it cannot apply because it's not
consistent with quantum mechanics. When your equation predicts a
singularity, it
just means you've gone beyond the domain of applicability of the equation.
There's
no singularity prior to the Big Bang and there's no singularity at the
center of a
black hole.
Yes. It seems unlikely that nature allow infinite curvature, infinite density
and so on.
However, there are definitely massive objects around the universe, which according to
general relativity have event horizons around them (a less contentious claim than there
being singularities inside them). These objects certainly walk and cluck like black
holes, unless some unknown effect prevents them collapsing to the point where an EH
forms they will be like them to any external observers - the article claims that EHs
don't form, but that the star in question explodes. As I asked before, wouldn't that
cause a huge emission of energy above what's observed from supernovae?
The BH does "explode" and emits a huge amount of energy when it evaporates due to Hawking
radiation. In Schwarzschild coord the event horizon is at t=+inf, so one way of looking
at it is that Hawking radiation is this enormous and intense radiation which from *our*
viewpoint, far from the BH, gets red shifted and gets spread out over billions of years.
But *at* the event horizon it radiates away all or most of the mass. This is like
Openheimer's "frozen star" picture. The BH never quite forms because the Hawking
radiation radiates away the mass as it tries to form - but it takes us billions of years
to see all the radiation (or virtually forever because the CMB keeps feeding energy to the
BH until it's temperature drops below 2.7K). It seems like this picture would go along
with Susskinds "fire wall".
Brent
Also the article doesn't say anything about supermassive BHs, I think?
Anyway, has anyone with the relevant physics knowledge examined the original
articles?
arxiv.org/abs/arXiv:1406.1525 <http://arxiv.org/abs/arXiv:1406.1525>
and
arxiv.org/abs/arXiv:1409.1837 <http://arxiv.org/abs/arXiv:1409.1837>
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