Price, Lew Paxton
Quantum Theory / Particle Physics
April 15, 2014
There was an experiment first performed by Albert Einstein, Boris Podolsky, and Nathan Rosen in 1935, later called the EPR experiment. It was a thought experiment in quantum mechanics and produced results so strange that Einstein rejected them as a flaw in quantum theory. In 1980, the experiment was physically performed by splitting a single photon into two, each of which had half of the energy of the "mother" photon. These two "entangled" photons were polarized at ninety degrees to one another. Whenever the polarization of one of the two was detected, it was a certainty that the polarization of the other would be at ninety degrees to the first. The first polarization detection could be either horizontal or vertical, and the experimenter had the choice, but once the first measurement was made, the second measurement would always be at ninety degrees to the first. The problem Einstein had with this experiment had to do with the fact that the removal of one polarization (by detecting it) made the second one predictable instantaneously, regardless of the distance between the two detections. This was an example of faster-than-light (FTL) communication to the extreme.