no its not irrelevant if you read bentheredone that's post. He's saying the reason black holes are defined by an escape velocity > c is because if they didn't warp spacetime thats how they would be defined.

Im saying, like what would you agreed with, is that if black holes didnt warp time the escape velocity of c still wouldnt matter

If there was no bending of space-time, I agree that escape velocity would not matter, as nothing would be effecting light's path.

Momentum would not matter either, as nothing would effect light's path, so I suppose that IDK the answer to why escape velocity effects light.

I think the only way you could justify using escape velocity to define black holes would be:

if the amount of mass needed to curve spacetime back to the center of a black hole "happened" to be equal to the amount of mass that gave an escape velocity > c. In which case it would just be a porportional thing and it would also be a huge coincidence i think. Also I have NO idea how someone could substantiate that to the point where its used in a definition and used in calculations

I could see that happening, but how could anything measure a black hole's effect on its surrounding space-time?

It's not the escape velocity of light. It's the escape velocity of anything. If anything was trying to get away from the black hole's gravitational force of attraction, that thing would need to travel at the speed of light if it were starting at the event horizon. That's how it is determined. If spacetime did not warp in the presence of extreme gravity, then if you were closer to the black hole's singularity than the event horizon, you would need to travel faster than the speed of light (i.e. v > c) in order to escape.

I think I see what you're saying, and I think I would agree that if spacetime didn't bend, then light itself would be able to escape from a black hole's event horizon, since it is only bending if you observe it from outside that area (the light itself thinks it's still going in a straight line, even though an outside observer can tell that that straight line is actually curved, sort of like moving forward in a roller coaster but truly moving in loops and spirals, etc).

Somehow I feel like this post is incomplete... but I can't quite see what I'm leaving out.

the deformation is gravity
gravity is a force , that acts constant thru time
which means the deformation is constant

and as an object is moving thru space , if the very space it is moving thru is itself moving in the opposite direction
well , it should be easy to see that , once the space is moving at the same speed that the object is , it will appear to be motionless ( from a suitable referance frame )

once we reach the point where the very fabric of space itself is moving towards a black hole faster than light moves
then it will appear that the light is moving backwards

but , ofc , we cant see light that moves backwards , we can only " see " light that reachs us
so what we see , from our refernce frame , is a region of space that is " black " , from which no light proceeds
hence the term " black hole "

This post was edited by Matao on Oct 21 2011 05:45pm

Are you suggesting that gravity is becoming deformed beside space-time, too?
I am confused by this part of your statement, as I thought that only space-time was being deformed.

This post was edited by L4d on Oct 21 2011 05:54pm

Idk, basically thats saying "if black holes acted differently than they do, this is how we would definie then". Its like applying a wrong definition and using it in calculations to something



the thing i said that you quoted wasnt directed at you

and I dont agree that the space is moving towards a black hole faster than light. Thats different from hows its described on wikipedia

Or its just becouse light is particles!
I defy sience