Technique for Extracting Information from a Black Hole
Once particles (or information) enters a black hole, it's lost forever right? Physicists at the California Institute of Technology have devised a technique to extract a single bit of information after it's been consumed. The first step, involves quantum entanglement. Having two entangled electrons allows one to be measured, to instantly "know" the state of the other. But this technique goes a step further and also uses quantum teleportation to imprint the state of one particle onto another (not entangled). Using these two principles, a scientist can capture an entangled photon of Hawking Radiation which gives information about a photon already inside the blackhole. A measurement of the blackhole's angular momentum is taken (an easy exercise for any advanced physicist) and an electron is tossed in. Despite it's small size, the electron affects the blackhole's angular momentum thanks to conservation laws. Combined with a new measurement of the blackhole's angular momentum (for the delta), a quantum teleportation of information from the consumed electron to the photon, and the entanglement from the photon to the observable photon ... a scientist can recover unknown information about the "lost" electron. slide rule ... drop
Is this at all practical? At the moment, not at all. It requires being able to accurately measure the angular momentum of a black hole the size of our sun (and they can get much larger) down to the granularity of an electron for starters. But the important part of the concept is developing techniques for future building.