User:Sguilford/sandbox

1.

The debates between Bohr and Einstein essentially concluded in 1935, when Einstein finally expressed what is widely considered his best argument against the completeness of quantum mechanics. Einstein, Podolsky, and Rosen had proposed their definition of a "complete" description as one that uniquely determines the values of all its measurable properties (“elements of reality”). Einstein later summarized their argument as follows:

2.

While the theory of quantum mechanics allows for immediate correlation of the states of entangled pairs upon measurement, it presents a violation of Einstein’s theory of Special Relativity. In a Gedanken experiment performed by Alain Aspect as well as members at Innsbruck, they showed how a pair of entangled photons immediately had correlated states upon measurement, regardless of the distance between. This correlation, given the fact that photons (light) were used, presented a conflict as it went against Einstein’s theory that no information can travel faster than the speed of light. Polarizing filters were separated at a distance great enough to allow for the last minute change of orientation of the polarizers once the photons are emitted from the source. Upon measurement, the two photons again had correlated polarizations in agreement with quantum mechanics, thus violating Bell's Inequality and ruling out the theory of a local hidden variable.