Bell inequality

Bell inequality is a concept in quantum physics that tests whether particles share a special connection called entanglement. It compares predictions from classical physics—where objects have definite properties—to quantum mechanics, which allows for correlations that are stronger and can't be explained by classical ideas. When experiments violate Bell inequality, they prove that entangled particles behave in a way that defies classical explanations, revealing the unique and non-intuitive nature of quantum reality. Essentially, Bell inequality helps us understand that the universe at the quantum level doesn't follow the same rules as everyday objects.