  How could the L-outcome change our knowledge/ignorance about the R-outcome if it has no influence on it? The simplest and most straightforward reply is that the L- and the R- outcome have a common cause that causes them to be correlated, so that knowledge of one outcome provides knowledge about the  other.[2]  Yet, the question is whether the predictions of orthodox quantum mechanics, which have been highly confirmed by various experiments, are compatible with the quantum realm being local in the sense of involving no influences between systems between which light and slower-than-light signals cannot travel (i.e., space-like separated systems). More particularly, the question is whether it is possible to construct a local, common-cause model of the EPR/B experiment, i.e., a model that postulates no influence between systems/events in the distant wings of the experiment, and that the correlation between them are due to the state of the particle pair at the source. In 1935, Einstein, Podolsky and Rosen believed that this is possible. But, as John Bell demonstrated in 1964, this belief is difficult to uphold.