We have one big advantage over what Bohr and Einstein had in the 1935 EPR debate. We can actually perform the experiment. Let's see what Nature decides. The Einstein point of view is that when the two photons are created, they both have a definite polarization that is negatively correlated with the other due to conservation of spin, but we do not know what they are. When one is measured, we then know the polarization of the other (it is the opposite polarization). Since both photons have a definite polarization from birth, there is no question of whether the measurement of one photon affects the polarization of the other. This is the core of Einstein's "element of reality" argument: "If, without in any way disturbing the system, we can predict with certainty (i.e. with probability equal to unity) the value of a physical quantity, then there exists an element of physical reality corresponding to this physical quantity." The QM point of view is that, after they are created, both photons exist in a state of superposition of all possible polarizations. Until measured, neither photon has a definite polarization. When one photon is measured, we now have the question of whether the polarization of the unmeasured photon is determined by the polarization of the measured photon. Here is Bohr's argument: "The criterion of physical reality proposed by EPR contains an ambiguity as regards the meaning of the expression "without in any way disturbing the system." Of course, there is in a case like that just considered no question of a mechanical disturbance of the system under investigation during the last critical stage of the measuring procedure. But even at this stage there is essentially the question of an influence on the very conditions which define the possible types of predictions regarding the future behavior of the system. Since these conditions constitute an inherent element of the description of any phenomena to which the term "physical reality" can be properly attached, we see that the argumentation of the mentioned authors does not justify their conclusions." What does Nature say? Bennet, Brassard and Ekert did the foundation work for a famous crypto-system that is now the basis for several commercial products. Bennet, Brassard and Ekert say this: "The EPR effect occurs when a spherically symmetric atom emits two photons in opposite directions toward two observers, Alice and Bob. The two photons are produced in an initial state of undefined polarization. But because of the symmetry of the initial state, the polarizations of the photons, when measured, must have opposite values, provided that the measurements are of the same type. For example, if Alice and Bob both measure rectilinear polarizations, they are each equally likely to record either a 0 (horizontal polarization) or a 1 (vertical), but if Alice obtains a 0, Bob will certainly obtain a 1, and vice versa." It appears that Nature agrees with Einstein. All the best John B.