light in black holes and space time

I watched videos, read articles, learned a lot about black holes and got confused:

Lets say that a light is doing its way inside a black hole toward the singularity.

If it's inside the event horizon, can this light escape it? I heard that if you want to escape from the event horizon you have to do it faster than the speed of light, can you escape it by the speed of light itself?

I also heard about a conspiracy which says that people use to think that a black hole called like that because even the light can't escape it, it says that it's called like that because the light is red-shifted so much that it becomes invisible, so I don't get it: can the light go back since it enters the event horizon or that it'll do its way toward the singularity and never return back?

In addition, there are differences between a ray of light doing its way in a black hole or a mass about the speed of light in a black hole?

• Classically, once light (or anything else) crosses the event horizon of a black hole, it cannot escape. – Prahar Jan 29 '16 at 13:01
• – Muze the good Troll. Dec 11 '16 at 5:28

If it's inside the event horizon, can this light escape it?

no , it cannot escape. Anything falling cannot see the ground, nor send message back, meaning in the sphere surface direction.

can you escape it by the speed of light itself?

no, it not sufficient

the light is red-shifted means that an object near the BH may emit or reflect this light which will be seen by a far observer as redshifted. The light of the inside cannot escape.

Unless we consider the Hawking radiation. Never observed, the theory seems very consistent. Some light from just beyond the event horizon might escape. A pair of particle-antiparticle is produced by the black hole's gravitational energy. One from the pair escapes and the other enters in the black hole, the balance reducing its mass.

In addition, there are differences between a ray of light doing its way in a black hole or a mass about the speed of light in a black hole?

It's a very difficult question because the proper time inside a black hole is a paradigm not acceptable all the other major theories : never a device would be able to measure it, nor any relevant measure information from the inside be able to leave the black hole.

Speed is the ratio distance on time. There is another issue with what we call time inside the black hole as seen from the outside. This question may explain it and an answer is provided : The arrow of time and the cosmology of a black hole interior .

But we can infer even if the result is a kind of opinion. The equation of the duration of the fall until the singularity hasn't any infinity in proper time. This equation depends mainly of the Schwarzschild radius and inversely of the mass/energy of the whole black hole. Then the marginal mass of what's falling doesn't account. Similarly , the fall duration may be computed in external time , but an infinity comes from a division by 0. In both cases, the mass/energy doesn't account.

• I understand.. thank you very much for the full and satisfying answers!! – Maor2871 Jan 29 '16 at 17:30
• Just to make sure one thing.. if we ignore the red-shifted thing, a far observer can see the light inside the event horizon? I mean the light shouldn't arrive the far observer that he'll be able to see it? – Maor2871 Jan 29 '16 at 17:39
• no, he cannot, nothing can go back in the direction from the singularity to the surface and from the surface to far away ( unless the Hawking radiation ). Some hope to see it in particular configurations. – user46925 Jan 29 '16 at 18:02