Thomas Young (Double-slit experiment)

Thomas Young's double-slit experiment demonstrates that light behaves as a wave. When a coherent light source shines through two closely spaced slits, the waves spread out and overlap, creating a pattern of bright and dark fringes on a screen. Bright areas occur where the waves reinforce each other (constructive interference), and dark areas where they cancel out (destructive interference). This experiment provided strong evidence that light has wave-like properties, challenging earlier particle-only theories and helping to shape our understanding of wave behavior and the nature of light.