Albert Einstein

Einstein’s genius was not a product of traditional schooling, which he detested for its reliance on rote memorization and "mechanical" teaching. After his family’s business failed in Munich, he dropped out of his gymnasium at age 15, eventually moving to Switzerland to avoid German military conscription. He was a "fractious" pupil, yet he was teaching himself calculus and Euclidean geometry by age 12, driven by a childhood fascination with a compass and the "hidden" forces of electromagnetism.

His intellectual foundation was solidified not in a lab, but at the Swiss Patent Office in Bern. As a "level III" technical examiner, he spent his days analyzing inventions like gravel sorters and synchronized clocks. This environment—isolated from the academic establishment—forced him to conduct profound "thought experiments" about the nature of time and signal transmission, leading directly to his revolutionary insights into relativity.

While still a patent clerk in 1905, Einstein published four papers that shattered the foundations of 19th-century physics. This annus mirabilis (miracle year) saw him explain Brownian motion (proving atoms exist) and outline the photoelectric effect (proposing that light behaves as particles, or "photons"). The latter discovery would eventually earn him the 1921 Nobel Prize, rather than his more controversial work on relativity.

Most famously, 1905 marked the introduction of Special Relativity and the equation $E=mc^2$. By demonstrating that mass and energy are two forms of the same thing and that the speed of light is the universe’s only constant, he upended the Newtonian view of an absolute, unchanging reality. These papers transformed a 26-year-old clerk into the most important scientist in the world.

In 1915, Einstein expanded his work into the General Theory of Relativity, a feat that remains the high-water mark of theoretical physics. He proposed that gravity is not an invisible tug between objects, but a curvature of space and time caused by mass. This theory predicted that light would bend around stars and that the universe itself was dynamic—concepts that birthed the field of modern cosmology.

Einstein's work even predicted the expansion of the universe, though he initially doubted his own math, adding a "cosmological constant" to keep his model static. He also laid the groundwork for the laser through his study of "stimulated emission." Despite these triumphs, he spent the last decades of his life in a lonely, unsuccessful pursuit of a Unified Field Theory—a single set of equations to link gravity with electromagnetism.

Einstein’s personal life was far less ordered than his physics. His first marriage to fellow physicist Mileva Marić was marked by a secret first daughter, Lieserl, whose fate remains unknown (likely given up for adoption or died in infancy). While Marić may have influenced his early work, their relationship soured; as part of their 1919 divorce settlement, Einstein promised her the money from his future Nobel Prize—which he duly handed over two years later.

His second marriage to his cousin Elsa Löwenthal provided a stable social platform, yet he engaged in numerous affairs and remained emotionally distant from his children. His younger son, Eduard, suffered from schizophrenia and was eventually institutionalized, while his elder son, Hans Albert, became a respected professor of engineering but maintained a strained relationship with his father.

In 1933, Einstein was visiting the U.S. when Adolf Hitler rose to power. As a high-profile Jewish intellectual, Einstein saw his property seized and his books burned by the Nazi regime. He never returned to Germany, settling at Princeton’s Institute for Advanced Study and becoming a U.S. citizen in 1940. His presence in America turned the country into the new global center for theoretical physics.

Though a lifelong pacifist, Einstein’s fear of a Nazi nuclear weapon led him to sign a 1939 letter to President Roosevelt, urging the U.S. to begin its own atomic research. This letter catalyzed the Manhattan Project. However, Einstein was never granted security clearance to work on the project due to his leftist political leanings and was later haunted by the destructive power his $E=mc^2$ formula had helped unleash.