Experimental tests of Bell's theorem

Experimental tests of Bell's theorem investigate whether particles like photons or electrons behave according to classical ideas of local realism or follow quantum mechanics. By measuring entangled particles—whose states are interconnected—scientists check if their correlations violate inequalities predicted by classical physics. Consistently, experiments have shown these inequalities are broken, supporting quantum mechanics and suggesting that particles are connected in ways that cannot be explained by local hidden causes. These results challenge our notions of locality and separate existence, confirming that, at the quantum level, particles can be instantaneously correlated regardless of the distance between them.