stringer bell

MinutePhysics, with 3Blue1Brown, explains Bell's theorem using a Venn diagram paradox and polarizing filters. It shows why no local hidden variable theory can reproduce quantum correlations.

Veritasium explains quantum entanglement and spooky action at a distance, walking through Bell's inequality and the experiments that rule out hidden variables, in under ten minutes.

A 1951 Bell System training film showing how telephone calls are routed through a step-by-step (Strowger) switching office.

3Blue1Brown, in collaboration with minutephysics, introduces the math of superposition and quantum states using polarized light. It builds up the quantum behavior of photons as a simple counting and probability problem.