Does Time Slow Down in a Black Hole?

  • Thread starter Thread starter Redrocket
  • Start date Start date
  • Tags Tags
    Blackholes Time
AI Thread Summary
Black holes exert immense gravitational forces, affecting the flow of time for outside observers due to time dilation. The discussion clarifies that black holes vary in size and that their mass, rather than their volume, determines their gravitational influence. It is emphasized that gravity acts on space-time, not the other way around, and that time does not stop within a black hole. The idea that the mass absorbed by a black hole could be less than perceived is challenged, as gravitational changes propagate at the speed of light. Overall, the effects of gravity and time dilation are well-explained by General Relativity.
Redrocket
Messages
1
Reaction score
0
It is stated that nothing can escape a black hole and they are gigantic and powerful enough to rotate a galaxy. The gravitational force of space acting on the black hole is immense. On this level of gravity could time it self be stopped in the black hole?

Therefore the amount of mass taken by the black hole could be a lot less then we think it just takes longer as time is slowed down.

Your thoughts…………
 
Space news on Phys.org
Redrocket said:
It is stated that nothing can escape a black hole and they are gigantic and powerful enough to rotate a galaxy. The gravitational force of space acting on the black hole is immense. On this level of gravity could time it self be stopped in the black hole?

Therefore the amount of mass taken by the black hole could be a lot less then we think it just takes longer as time is slowed down.

Your thoughts………

My thoughts are that you put your question(s) in pretty unclear fashion, except for time slowing down, which is true for outside observer.

- Black holes are not necessarily gigantic. It is mass/volume ratio, or density, that qualifies region of space, occupied by that mass, to become a black hole.

- Mass is the one that causes gravity, not the space. But it is true that space - time is the "medium" through which gravity acts, so you can tell that space - time is the one who exerts "force" on a object.

- What do you mean by "Therefore the amount of mass taken by the black hole could be a lot less then we think it just takes longer as time is slowed down". It just takes longer for what?
 
Redrocket said:
It is stated that nothing can escape a black hole and they are gigantic and powerful enough to rotate a galaxy.
BHs come in all sizes. Some are small, some are huge and live at the centre of galaxies (they do not "rotate the galaxy" - galaxies will do just fine without them.)

Redrocket said:
The gravitational force of space acting on the black hole is immense.
It is the gravitational force of the BH that acts on space, not the other way around.

Redrocket said:
On this level of gravity could time it self be stopped in the black hole?
Why would it?

Redrocket said:
Therefore the amount of mass taken by the black hole could be a lot less then we think it just takes longer as time is slowed down.
The changes in the gravitational field around a black hole propogate at the speed of light.
 
mcampbell said:
It is stated that nothing can escape a black hole and they are gigantic and powerful enough to rotate a galaxy.
Er, well, not quite. The supermassive black holes at the centers of galaxies sound impressive, but they still only make up a tiny fraction of the total masses of the stars in galaxies.

mcampbell said:
Therefore the amount of mass taken by the black hole could be a lot less then we think it just takes longer as time is slowed down.
Well, time dilation is fully taken into account by the gravitational field predicted by General Relativity.
 
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
Hi, I’m pretty new to cosmology and I’m trying to get my head around the Big Bang and the potential infinite extent of the universe as a whole. There’s lots of misleading info out there but this forum and a few others have helped me and I just wanted to check I have the right idea. The Big Bang was the creation of space and time. At this instant t=0 space was infinite in size but the scale factor was zero. I’m picturing it (hopefully correctly) like an excel spreadsheet with infinite...
Back
Top