Quantum Weirdness: Two times zero doesn't always equal zero

http://www.spectrum.ieee.org/aug08/6609

by soundsop • 18 years ago

13 5 18 years ago

spectrum.ieee.org

lisper• 18 years ago

You don't need quantum mechanics to produce this kind of a result. One-time-pad encryption does essentially the same thing. Both the "key" and the "ciphertext" (I put them in scare quotes because they are mathematically indistinguishable) by themselves are just random bit strings containing zero information. But together they contain all the information of the original cleartext.

soundsop• 18 years ago

I don't think that's a correct analogy. This announcement is about signal detection in the presence of noise not information decryption.

My interpretation of the article is that two noisy quantum channels (where each individual channel is too noisy to recover any information) can have their noisy results combined to recover clean information.

There is no classical analogy to this case. If two classical channels are too noisy to recover information from them individually, then there is no way to combine the noisy results to recover any information.

boredguy8• 18 years ago

Umm, isn't this what Bell Labs found under Gell-Mann in like 40 years ago? You overcome transmission problems with redundancy. Or am I missing something?

braz2• 18 years ago

Actually no... They were not trying to overcome noise. They were actually testing what can come out of combining "entangled" noisy channels. The fact that they retrieve information out of nothing (noise is the equivalent of "nothing" information-wise) is the beauty of their work.

ars• 18 years ago

Isn't this the same as spread spectrum broadcasting?

Quantum Weirdness: Two times zero doesn't always equal zero

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