Robert Millikan (physicist)

Robert Millikan was an American physicist best known for his oil-drop experiment, which measured the charge of the electron with high precision. By observing tiny charged oil droplets suspended between charged plates, he determined the fundamental unit of electric charge. His work confirmed that electric charge is quantized—existing only in discrete amounts—and helped solidify our understanding of atomic structure. Millikan's measurements played a crucial role in the development of modern physics, and he received the Nobel Prize in Physics in 1923 for his groundbreaking work on electric charge and photoelectricity.