In an EPR experiment, once you have measured one particle’s spin, you know the spin of the opposite particle instantaneously.

Your ability of getting the total information at once is due to the fact that you know partial information in advance. Since the time of the separation of the two particles, you have already known that “the opposite particle must have an opposite spin”. 

Let

A = the spin of your particle

B = the fact that the opposite particle must have an opposite spin

C = the spin of the opposite particle

knowing A + knowing B = knowing C

There are no superluminal (faster-than-light) communications between the two particles. So the whole EPR experiment is compatible with classical locality, aka special relativity.

The strange thing is the quantum non-locality part.

— Me@2012-04-04 5:21:25 PM  

2013.01.01 Tuesday (c) All rights reserved by ACHK