PDA

View Full Version : black hole question


photon
Sep11-03, 02:56 AM
Why is it said that a black hole is a literally bottemless pit in space-time? If it weren't bottemless, then the singularity inside would not have to be of infinite density.

I'm not sure if I have missed anything important, so PLEASE help!

HallsofIvy
Sep11-03, 09:34 AM
Yes, but a black hole is, by definition, of infinite density.\\


Well, the way you are putting it, that's true. In general, a black hole only has to be massive enough that light cannot escape it. (It's "escape velocity" is greater than the speed of light.)

A large (in volume) black hole would not have to have infinite density and would not be "a literally bottemless pit in space-time".

bogdan
Sep11-03, 03:29 PM
What do you mean by "density" ?
Huh ?
mass/volume ?
mass=finite
volume<>0...(the radius of the horizon is not 0...)
so density is not infinite...or am I wrong ?

meister
Sep12-03, 03:12 AM
I think he was talking about the singularity's density.