WHAT LIES AT THE HEART OF A BLACK HOLE?
According to general relativity calculations, as one passes the event horizon (the point of no return) of a black hole, space and time switch roles. The inevitability of moving forward in time becomes instead the unavoidable plunge to the singularity at the center of a black hole. And that singularity prevents our knowing what lies beyond. It could be a wormhole, or shortcut, to another place in our universe or even to another universe entirely. The singularities—the mathematical infinities that crop up in general relativity—are a clear sign that Einstein did not have the final word on gravity. At singularities the laws of physics appear to break down. More likely, our understanding is breaking down. M-theory has tamed some of the simpler singularities of general relativity, with the fuzziness of quantum mechanics taking the sharpness off these very pointy regions of space and eliminating the mathematical infinities. While M-theory has yet to determine precisely what lies at the heart
