Detecting Black Hole Radiation: How Does It Work?

[BigStelly]

OK guys I know that one of the ways that black hole radiation is detected is by detecting some sort of radiation.

My question is... is this radiation or whatever released at a point were light cannot escape from the black hole? I mean the escape velocity from black holes is immensly greater than even the speed of light so how exactly does the radiation or whatnot escape the gravitational field? Or does it happen before an object crosses the event horizon? I am curious exactly how this works. Thanks

 

[cyeokpeng]

If I am not wrong, what I have learned is that it has something to do with thermodynamics of the black hole system. There is existence of virtual particles in empty space, and one type is beyond the event horizon and its anti-particles is outside the event horizon. In effect, you will see a net dissipation of particle radiation from the black hole, which in effect is its black hole radiation.

 

[selfAdjoint]

OK guys I know that one of the ways that black hole radiation is detected is by detecting some sort of radiation.

My question is... is this radiation or whatever released at a point were light cannot escape from the black hole? I mean the escape velocity from black holes is immensly greater than even the speed of light so how exactly does the radiation or whatnot escape the gravitational field? Or does it happen before an object crosses the event horizon? I am curious exactly how this works. Thanks

Hawking radiation, as it is called is generated outside (just outside) the event horizon, which is the limit within which nothing can escape the black hole. A particle and its antiparticle are "promoted" from the quantum vacuum by the gravitational energy of the black hole. One of them falls into it, and the other escapes. Because creation of the pair took some of the black holes's energy, and only half of it came back through the infalling particle, the black hole's gravity, and hence its mass, is diminished.

 

[BigStelly]

So I would be correct in assuming that none of this radiation and whatnot occurs once objects have crossed the event horizon?