Bell inequalities

Bell inequalities are a set of mathematical inequalities that test the predictions of quantum mechanics against classical physics. They reveal that certain correlations observed in entangled particles cannot be explained by any local hidden variable theory, which assumes that particles have predetermined properties independent of observation. If experiments violate these inequalities, as many do, it suggests that particles are interconnected in ways that defy classical intuition, challenging our understanding of reality and hinting at the peculiar nature of quantum entanglement, where the state of one particle instantly influences another, no matter the distance between them.