Why can't light escape from a black hole?
I've heard that light can't escape from a black hole. Can it? If not, why?
Related questions on Physics.SE: http://physics.stackexchange.com/questions/25369, http://physics.stackexchange.com/questions/46591, http://physics.stackexchange.com/questions/33916, http://physics.stackexchange.com/questions/8477, http://physics.stackexchange.com/questions/28297, and probably more.
A black hole has an event horizon which 'marks the point of no return'. So yes, light cannot escape from a black hole.
Why? Well, think of a 'spacetime fabric'. It's the easiest way to understand the physics at work here, in my opinion.
Usually, the fabric would look like this:
However, a black hole has so much gravity that one could say it 'rips' the spacetime fabric:
When the light hits this area of amazingly intense gravity, it simply cannot get out - the light travels 'along' the fabric, and since there is a rip in the fabric, one could say it simply goes away - it becomes part of the singularity.
This is a simplification, of course, but it's enough to understand at least part of the physics behind this phenonenom.
Is the time dilation effect of the event horizon itself enough to prevent light from escaping? Or is that only a small component of what keeps light trapped in a black hole?