Thomas Young's double-slit experiment

Thomas Young's double-slit experiment, conducted in 1801, demonstrated the wave nature of light. When light passes through two closely spaced slits, it creates an interference pattern on a screen behind them, with alternating dark and light bands. This pattern results from light waves overlapping and reinforcing or canceling each other. Remarkably, when light is sent through one slit, it behaves like a particle, producing a single band. However, with both slits open, it exhibits wave behavior. This experiment highlights the dual nature of light, suggesting that particles can behave as waves under certain conditions, fundamental to quantum mechanics.