Quantum Correlations in Classical Systems

Bell’s inequality is supposed to be universally valid. No local theory should violate it with space-like separated observables. Yet, classical mechanics is full of counter examples, especially in the case of binary energy redistribution. The explanation is that “space-like separation”, as used in Bell’s argument, is not a theory-independent concept. It only applies to models with jointly distributed variables, where coordination between measurements is required for Bell violations. In contrast, alternative transformations cannot influence each other in classical physics, yet they still display “non-classical” patterns of coincidence. This is demonstrated with a macroscopic fluid splitter that has the same output distributions and the same correlations as a Stern-Gerlach quantum spin analyzer.