Re: A partial black hole?

Mike Huskey wrote:

> On Tue, 26 Feb 2008 00:55:49 GMT, throopw@[EMAIL PROTECTED]
 (Wayne Throop)
wrote:
> 
>> : Mike Huskey <mikehsk@[EMAIL PROTECTED]
>
>> : Let see. Neutron star with escape velocity of
.999999999999999999999999 C.
>>
>> No such thing.  It'd have collapsed long since, since even neutrons
couldn't
>> sup****t the forces.  But let's say that there was.
> 
> Then what is it if it isn't a neutron star, and it isn't a black hole?
> It is very very dense, but can theoretically be observed.

There's no force known in our Universe which could sup****t such a 
structure.  Neutron degeneracy, as you get with neutron stars, is 
currently the high bidder, and that's not enough to withstand the 
densities you'd need.  A neutron star inherently has less density than 
what you need there, so it's well outside what would be its own event 
horizon.  If you try to compress it/add more mass to get higher density, 
then you will tip it over the edge where neutron degeneracy fails and 
the object would collapse into a black hole.  There's no known middle 
ground.

Speculative ideas about quark stars (neutron stars whose interior has 
been converted into mostly strange quarks) could get higher density than 
a neutron star, but still not enough to satisfy the construction 
requirements for which you seek.

One can, of course, speak hypothetically about such things, though.

> I still don't get it. Escape velocity above the horizon is less than C.
> At the horizon is C, and below is greater than C. So nothing gets out.
> Its just an immaterial boundary zone. Yes, conditions are extreme, but I
still
> don't see where the laws of physics suddenly go berserk.

They go "berserk" because that's what general relativity says.  Once an 
object becomes dense enough that not even light can escape, then the 
structure of spacetime is sufficiently distorted that anything ever 
entering its event horizon will be rapidly and totally destroyed -- and 
that includes anything that was originally in the object.

It's simply a tipping point, of which it isn't too hard to find other 
examples in physics:  white dwarfs vs. neutron stars, solids vs. gases, 
nuclear critical mass chain reactions, etc.

-- 
Erik Max Francis && max@[EMAIL PROTECTED]
 && http://www.alcyone.com/max/
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