Perhaps the most significant individual of the 20th century, Albert Einstein's contributions to science reshaped physics in ways that continue to be explored and led to the development of atomic energy and the atomic bomb.
A nonobservant German Jew, he was a late bloomer as a student, showing slow language development. Although folklore claims Einstein was a poor math student, he had a knack for mechanics and geometry at an early age, teaching himself geometry and calculus from a copy of Euclid's Elements.
Any reputation he may have had as a poor student came from his dissatisfaction with the curriculum at the German gymnasiums; at age 16 he left school, failed his university entrance exam for the Federal Polytechnic Institute (FPI), and took steps toward formulating his theories of relativity.
He was accepted at the FPI the following year and four years after that was granted a teaching position. His first published paper, "Consequences on the Observations of Capillarity Phenomena," hinted at his hopes for universal physical laws, binding principles that would govern all of physics.
When he graduated FPI, he took a job as a patent clerk and continued to work on scientific papers in his spare time. Four such papers were published in the Annalen der Physik journal in 1905, each of them major contributions to the shape of modern physics. Today they are called the "Annus Mirabilis" ("Extraordinary Year") papers.
The Annus Mirabilis papers concerned the photoelectric effect; Brownian motion, Einstein's treatment of which helped provide more evidence for the existence of atoms; matter and energy equivalence, the paper that included Einstein's equation E=mc2; and special relativity, which contradicted Newtonian physics by stipulating the speed of light as a constant.
The importance of these papers cannot be overstated—they continue to be relevant to physicists today, and the photoelectric effect paper had a huge effect on the development of quantum mechanics and earned Einstein a Nobel Prize.
It was during the war years that Einstein introduced his theory of general relativity, more radical than his special relativity. The general relativity theory replaces that most basic and intuitive of concepts from Enlightenment physics, Newtonian gravity, with the Einstein field equation.
Under general relativity there is no ether or constant frame of reference, and gravity is reduced simply to an effect of curving space-time. Because of World War I, Einstein's writings were not readily available to the rest of the world, but by war's end general relativity became a controversial topic.
Einstein's importance to the scientific field of his day was assured when journals reported that experiments conducted during a 1919 solar eclipse confirmed general relativity's predictions about the bending of starlight in contradiction to the effects demanded by Newtonian models.
Throughout the next two decades Einstein sparred in papers and debates with other scientists, particularly about quantum theory, which he viewed as an inherently incomplete model of physical reality and hence an incorrect one. When the Nazis came to power, he was working at Princeton University in the United States, where he remained after renouncing his German citizenship.
Fearing the Germans would develop nuclear weapons, Einstein wrote to President Franklin Delano Roosevelt advising the research and testing of fission bombs, a suggestion that led to the United States's Manhattan Project, the outcome of which was the development of the first atomic bomb and its use to end the war in the Pacific.
Einstein continued to search for a "unified field theory" that would describe all physical laws in one theory, the quest that had driven everything from his capillarity paper to his theory of general relativity. He lived a quiet life, refusing the request of the government of Israel that he serve as its president, and died in 1955 of an aneurysm.