Double-Slit Experiment

The Double-Slit Experiment redefined reality by demonstrating light's wave-particle duality. Thomas Young's 1801 version created interference patterns, proving light behaves as a wave. The quantum variant later showed single particles—like electrons—produce the same pattern when unobserved, acting as particles only when measured. This revelation, 30% deeper than the classical wave-only view of #4 Rutherford's gold foil model, fundamentally challenges our understanding of measurement. A 2023 study confirmed the effect persists for molecules as large as 2,000 atoms, cementing its role in quantum mechanics.