Understanding communication via QE - is filtering the only obstacle? to FTL communication FTL = faster than light In a two-photon (i.e. entangled photons) double slit or similar experiments - Information cannot be sent FTL because there are no patterns (mapping to which-way or no-which-way) on the screen yet. to get the patterns we have to filter out noise etc to filter out noise we have to compare/match both the photons via co-incidence counter. to compare both the photons we need a classical channel which will of course work at or slower than the speed of light Question 1: If Alice and Bob were sitting in a relatively noiseless (i.e free from stray photons, enough to discern an interference pattern) environment, could they, in principle, communicate FTL? Note: It may not be possible to have an environment that is free of stray photons. however for now let's ignore this fact. Question 2: (how) Does FTL communication, involving massless/energy-less transmission method, violate relativity? Note: Massless/energy-less information transfer might not be possible and this might be a fundamental, however for now we are ignoring this point.