• Support PF! Buy your school textbooks, materials and every day products via PF Here!

Black hole question

  • Thread starter photon
  • Start date
123
0
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

Science Advisor
Homework Helper
41,711
876
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".
 
191
0
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 ?
 
56
0
I think he was talking about the singularity's density.
 

Related Threads for: Black hole question

  • Posted
Replies
5
Views
1K
Replies
2
Views
775
  • Posted
Replies
5
Views
2K
Replies
1
Views
1K
  • Posted
Replies
1
Views
898
  • Posted
Replies
3
Views
3K
  • Posted
Replies
3
Views
1K
  • Posted
Replies
1
Views
3K

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top