Young's Experiment, conducted by Thomas Young in 1801, demonstrated the wave nature of light. In this experiment, light passed through two closely spaced slits, creating an interference pattern on a screen behind them. This pattern consisted of alternating bright and dark bands, indicating that light waves were overlapping and interacting. The results of Young's Experiment challenged the prevailing particle theory of light, suggesting instead that light behaves like a wave. This groundbreaking work laid the foundation for the field of wave optics and significantly advanced our understanding of light and its properties.