Saturday, September 11, 2010

Hawking's Nobel

Some people have argued that the inner radius of a black hole is not a physical, i.e. measurable, quantity. In fact I share that view, seeing no reason why the inner radius should coincide with the radius apparent to an observer on this side of the horizon. If those arguments are correct, they empty Hawking's theory of black hole radiation of any physical content, since its predictions would depend on a free parameter. On the other hand, should black hole radiation be detected, those arguments would be proven erroneous.