Dave5

We have failed to find a quantized theory of gravity. We have no description of what truly happens at the boundary of a black hole. But we have learned in our quantum wanderings that physical, three-dimensional entities are not exactly what they appear to be. Indeed, they are shallower: black holes may truly be described only by their surfaces, their boundaries, their edges, rather than their full extents.

And when we apply this same chain of reasoning, that holography is a vital component to the quantum gravitational puzzle, out comes the AdS/CFT correspondence and a potential path to string theory glory.