The 1919 Eclipse That Proved Einstein Right
British astronomer Arthur Eddington led two expeditions—one to Príncipe Island off West Africa, another to Sobral, Brazil—to photograph stars near the Sun during a total solar eclipse. Einstein's general relativity predicted starlight would bend around the Sun's gravity by a specific amount, different from Newton's prediction. Eddington measured the deflection.
Results announced in November 1919 matched Einstein's predictions. Headlines worldwide declared Newton overthrown. Einstein became an instant celebrity, the most famous scientist alive.
Established solar eclipses as crucial tests of fundamental physics. General relativity became the foundation for modern cosmology, GPS satellite corrections, and gravitational wave detection a century later.
Modern eclipse observations continue this tradition, using the brief darkness to study phenomena normally invisible—the Sun's corona, atmospheric effects, and radio signal propagation.