Sail the Seven Dimensional Seas?
By Juan Maldacena
“One can consider, therefore, a pair of black holes where all the microstates are “entangled.” Namely, if we observe one of the black holes in one particular microstate, then the other has to be in exactly the same microstate. A pair of black holes in this particular EPR entangled state would develop a wormhole, or Einstein-Rosen bridge, connecting them through the inside. The geometry of this wormhole is given by the fully extended Schwarzschild geometry. It is interesting that both wormholes and entanglement naively appear to lead to a propagation of signals faster than light. But in either case this is not true, for different detailed reasons. The net result is the same: we cannot use either of them to send signals faster than light. This picture was developed through the years starting with work by Werner Israel . Most recently, Leonard Susskind and I emphasized this ER=EPR connection as a way to resolve some apparent paradoxes regarding the black hole interior [5, 6].
There are several interesting lessons regarding this picture of geometry emerging from entanglement. Perhaps the deepest one is that the peculiar and strange property of quantum mechanical entanglement is behind the beautiful continuity of spacetime. In other words, the solid and reliable structure of spacetime is due to the ghostly features of entanglement. As we entangle two systems with many degrees of freedom, it seems possible to generate a geometric connection between them, even though there is no direct interaction between the two systems.”