Friday, August 27, 2004

"QUANTUM: teleportation exits realm of sci-fi"
The problem with teleportation � the real beam-me-up-Scotty kind--is not its principles, which appear to be sound, but in the devil's details. Fact: There is no way to "encode" all the detailed information in a single quantum state, much less the entire human body (which is composed of about 100,000,000,000,000,000,000,000,000,000,000 "quantum bits," or qubits). It would take a 1,000-km cube to house that much information on CD-ROMs. Even if you could automatically assemble them into Captain Kirk, just to transmit their data with theoretically perfect fat-pipe optical fibers would take more than 100 million centuries. Nevertheless, researchers in the lab have begun to demonstrate true teleportation--not the sort that disassembles Kirk and puts him back together on the planet surface, but the kind that delivers the devil's details from point A (for Alice) to B (for Bob) despite there being no way to encode all that data. How? By not encoding it. Instead, Alice mixes the unencodable data with the quantum state of an entangled pair for which Bob has the twin--and presto! The phenomenon that Albert Einstein called "spooky action at a distance" teleports the unencodable quantum states, qubit per qubit.