Einstein & Relativity
The theory that redefined space, time, mass, and energy
14.1 The Annus Mirabilis
In 1905, Albert Einstein (1879–1955) published four papers that transformed physics: the photoelectric effect (launching quantum theory), Brownian motion (confirming atoms), special relativity, and the mass-energy equivalence E = mc².
14.2 General Relativity
In 1915, Einstein published general relativity, showing that gravity is the curvature of spacetime caused by mass and energy. The theory predicted the bending of light by gravity, confirmed during the 1919 solar eclipse, making Einstein a global celebrity.
14.3 Legacy
General relativity governs GPS satellites, predicts black holes and gravitational waves (detected by LIGO in 2015), and underpins modern cosmology. Einstein's work also planted the seeds of quantum mechanics, which he himself never fully accepted.