[AlessandroF6587]

It wluld be interesting to send one beam alternatively throught a linear or circular polarizer. Then you can check the polarization on the other beam and see if you have faster than light information transmission. With all the implications about causality.

[n4r9]

Unfortunately you can't transmit information this way, even in theory. The polarizer has a 50-50 chance of testing one way or another, and the other beam will has the opposite polarization.

[orlp]

Well, yes and no. In certain games you do gain an advantage this way over a classical opponent, it's called quantum pseudo-telepathy: https://en.wikipedia.org/wiki/Quantum_pseudo-telepathy. It sounds like quackery but it's a real thing.

[ynniv]

The CHSH experiment measures more pairs of entangled photons passing through two similarly oriented polarizers than two orthogonal ones, regardless of the source's angle of polarization, though the effect is small enough that it can only be seen statistically. Rotating one observing polarizer should then cause an immediate change in the number of photons passing the other observing polarizer, regardless of distance. It seems absurd, but that's the current understanding.

[AlessandroF6587]

That's not it if you discriminate between linear and circular polarization. You can use a phase inversion mirror to do it. That's the point of the experiment.

[schwoll]

They did an experiment like this called the Quantum Eraser Experiment. The outcome is quite strange and I still don't know if I fully understand the result. It suggests potential retro-causality or at least superdeterminism or some kinds of weird time independent action. People will claim I'm just misinterpreting the experiment but I've yet to hear any explanation that doesn't hand wave some critical things away.