Quantum Entanglement Explorer

Simulation

Understanding Local Realism and Entanglement

Local Realism is a classical worldview based on two fundamental assumptions:

• Realism: Objects possess definite properties (like position, momentum, or spin orientation) independent of observation. Measurement simply reveals these pre-existing values.
• Locality: Influences cannot travel faster than the speed of light. An action performed on one object cannot instantaneously affect a distant object.

Quantum Entanglement challenges this classical picture. When particles are entangled:

• They do not have definite individual properties before measurement. Instead, their collective state is defined, but individual outcomes are probabilistic until one particle is measured.
• Measuring a property of one entangled particle instantaneously influences the properties of the other(s), regardless of the distance separating them. This is often called "spooky action at a distance."
• The correlations observed between measurements on entangled particles are stronger than what any local realist theory could predict (as famously shown by Bell's Theorem). This suggests that either our notion of realism (pre-existing properties) or locality (no faster-than-light influence), or both, must be revised for the quantum world.

This app simulates the decay of a massive particle into three smaller particles. If entangled, their fates are linked. Try measuring their spins at different angles and observe the correlations.