If you're interested in this, you should read up on Bell's theorem. [1] [2] The explanation of it I like best is this one (I don't remember where I originally

If you're interested in this, you should read up on Bell's theorem. [1] [2] The explanation of it I like best is this one (I don't remember where I originally read it): It involves a two player game, the players completely separated from each other. Each is independently shown X or Y. Each player must then give either answer A and B. They win the game if: - when both are shown X, they choose different answers - otherwise, they choose the same answer They can choose a strategy to follow before, but after they're physically separated, each player's decision can only depend on what they're shown (X or Y). Given this restriction, even allowing the players to have (pseudo-)non-deterministic strategies, they'll win with a chance of 75%. However, if the players' strategy involves each having half of an entangled pair of photons, they can make measurements of its spin at one of two predetermined angles (P1X = 0, P2X = 67.5, P1Y = 45, P2Y = 22.5), based on if they see X or Y. Their answer is based on whether they get a spin-up or spin-down measurement. With this strategy, they win about 85% (cos^2(tau/16)) of the time. [1] http://en.wikipedia.org/wiki/Bell%27s_theorem http://en.wikipedia.org/wiki/Bell%27s_theorem [2] http://www.askamathematician.com/2010/06/q-how-it-is-that-bells-theorem-proves-that-there-are-no-hidden-variables-in-quantum-mechanics-how-do-we-know-that-god-really-does-play-dice-with-the-universe/ http://www.askamathematician.com/2010/06/q-how-it-is-that-be...