Einstein Publishes Relativity: Gravity Rewritten for Ages

Albert Einstein published his general theory of relativity in November 1915, presenting the final field equations to the Prussian Academy of Sciences in Berlin on November 25. The paper described gravity not as a force acting between objects, as Newton had proposed, but as the curvature of spacetime caused by the presence of mass and energy. It was the most radical reconception of gravity since Newton published the Principia Mathematica in 1687. Born in Ulm, Germany on March 14, 1879, Einstein had already revolutionized physics once. His 1905 papers on special relativity, the photoelectric effect, and Brownian motion had established him as one of the leading physicists in the world. But special relativity applied only to objects moving at constant velocity. It said nothing about gravity or acceleration. Einstein spent ten years developing general relativity, wrestling with the mathematics of curved spacetime. The final equations, elegant and compact, described how mass tells spacetime how to curve and how curved spacetime tells objects how to move. The theory predicted phenomena that Newtonian gravity could not explain: the precise precession of Mercury's orbit, the bending of light around massive objects, and the expansion of the universe itself. The first major confirmation came during a total solar eclipse on May 29, 1919, when British astronomer Arthur Eddington measured the deflection of starlight passing near the Sun. The measurements matched Einstein's predictions. The results, announced at a joint meeting of the Royal Society and the Royal Astronomical Society in London, made front-page news worldwide. Einstein became the most famous scientist on earth overnight. General relativity has since been confirmed by every experimental test, including the detection of gravitational waves by LIGO in 2015, exactly one hundred years after the theory was published. GPS satellites must account for relativistic time dilation to maintain accuracy. The theory remains the foundation of modern cosmology, describing black holes, the Big Bang, and the large-scale structure of the universe.