Bell’s inequality

Bell's inequality, also known as Bell's theorem, is a fundamental concept in quantum physics that addresses the nature of reality and the implications of quantum entanglement. It stems from the work of John Bell, who showed that certain assumptions about the universe lead to a mathematical contradiction when applied to quantum mechanics.12

The core idea is that if two particles interact, they remain connected in a way that their properties are correlated, regardless of the distance separating them. This phenomenon is called quantum entanglement. Bell's theorem demonstrates that if we assume locality (no action at a distance) and that quantum mechanics accurately describes these entangled particles, then the universe must exhibit nonlocality. This means that events in one location can instantaneously influence events in another, a concept that challenges classical physics.312