Resolving the Conundrum of the Mermin Device

In 1981, Mermin published a now famous paper titled, "Bringing home the atomic world: Quantum mysteries for anybody" that Feynman called, "One of the most beautiful papers in physics that I know." Therein, he presented the "Mermin device" that illustrates the conundrum of entanglement per the Bell spin states for the "general reader." He then challenged the "physicist reader" to explain the way the device works "in terms meaningful to a general reader struggling with the dilemma raised by the device." In this paper, we show how the principle of conservation per no preferred reference frame (NPRF) answers that challenge, but still leaves a mystery for those who seek constructive explanation via hidden variables or causal mechanisms. In short, the conservation (SO(3) invariance of the spin measurement outcomes in the same reference frame) following from the SU(2) symmetry of the Bell spin states holds only on average in different reference frames (for different measurements), not on a trial-by-trial basis. Therefore, this "average-only" conservation constitutes an adynamical constraint with no overt evidence for an underlying dynamical mechanism, so we justify it via the principle of NPRF in direct analogy with the postulates of special relativity. Thus, we see a common theme in both relativistic and non-relativistic modern physics relating the fundamental constants c and h, respectively, per principle explanation and the restricted Lorentz symmetry group.