✔ 最佳答案
Don't give Hawking credit for that. It was not his idea.
This is the basis for the so called holographic theory of the black hole. Quantum mechanics requires that information is never lost to the universe. It can be scattered around, but never lost (information in quantum mechanics is the quantum state vector which is all that can known about a quantum system). When Hawking proposed Hawking radiation, he claimed that the radiation that was emitted was random and contained no information about what went into the black hole. Since this violated a pillar of quantum mechanics, many were uncomfortable with idea. Since then, theories have shown that information can be retained at the event horizon, and Hawking radiation is encoded with that information so it is not lost.
This however created a seeming paradox. There is a theorem in quantum mechanics called the no clone theorem which says the laws of physics will not allow a state vector to be cloned without destroying the original state vector. You can't produce another copy of the state vector and still retain the original. This presented a paradox since information does pass into a black hole yet it must be stored on the event horizon in a way that can be emitted. A proposal was made that the black hole had some of the properties of a hologram which could resolve the paradox.
The resemblance between a black hole and holograms in everyday life is really just conceptual at best. Holograms store not only color and intensity of light like a phtograph, it also stores interference information on its 2-d surface. The interference information allows it to store 3-d relationships on the 2-d surface, as well as color and intensity. The analogy with a black hole is that 3-d information is stored at the 2-d surface of the black hole, and the 3-d interior of the black hole is in some sense a projection of the surface information (it's of course much more complicated than that).
While that may seem a little ( or a lot) crazy, various theories and calculations show that the entropy of the black hole is strangely dependent on the area of the event horizon and NOT the volume of the black hole as would be expected. Since entropy can be a measure of the total number of states within the black hole, which in turn is a measure of the total amount of information possible in the black hole, having that depend on the area of the event horizon seems to indicate that 3-d information is store in a 2-d event horizon region. Interestingly, the entropy of the black hole is proportion to the number of Planck 'bits' that can cover the event horizon.