Re:A Dismal Guide to Concurrency
by jessriedel on Tuesday April 13, 2010 @01:17AM
(#1261228)
No. Causality can only propagate at the speed of light, with or without quantum mechanics.
My understanding is that 'entanglement' is like having two urchins each draw a ball from a bag with a black/white pair. One urchin goes East, the other goes West.
Assuming they arrive at A and B, respectively, this may be useful somehow. But it cannot really communicate new information from A to B.
(Unless the balls are carried unobserved, and one of the recipients - by staring real hard ? - can somehow choose the color of the ball he is unwrapping.)
Re:A Dismal Guide to Concurrency
by jessriedel on Friday April 16, 2010 @12:52PM
(#1271109)
Your analogy is correct inasmuch as the urchins cannot communicate for the same reason the Alice and Bob, each with one particle of an entangle pair, cannot communicate. But it can be shown by very clever experiments that the future statistical observations of Alice and Bob cannot be explained by assuming each had a particle with properties fixed when the two parted ways. Entanglement is very subtle.
You can't avoid it by using electrons instead of street urchins. It's impossible for an event happening in one place (eg data changing inside one computer or process) to affect any other place (eg other computers or processes) until the information has had time to travel between them.