Albert Einstein (March 14, 1879 - April 18, 1955) was a physicist who first proposed the theory of relativity. He was awarded the 1921 Nobel Prize for his account of the photoelectric effect; however, the announcement of his award was not made until a year later, in 1922. His theoretical work suggested the possibility of creating an atomic bomb.
Einstein was born March 14, 1879 at Ulm in Württemberg, Germany. He grew up in Munich and later in Italy, and received his higher education in Switzerland. At age 17 he renounced his German citizenship and later, in 1901, was accepted as a Swiss citizen. He obtained his doctorate in 1905. That same year, he wrote four articles that lay the foundation for modern physics.
The first article in this miracle year is remembered as his study of Brownian motion. It established empirical evidence for the reality of atoms. Before this paper, atoms were recognized as a useful concept, but physicists and chemists hotly debated the question of whther atoms were real things. Einstein's statistical discussion of atomic behavior gave experimentalists a way to count atoms by looking through an ordinary microscope. Wilhelm Ostwald, one of the leaders of the anti-atom school, later told Arnold Sommerfeld that he had been converted to a belief in atoms by Einstein's complete explanation of Brownian motion.
The second paper of 1905 proposed the idea of "light quanta" (now called photons) and showed how they could be used to explain such phenomena as the photoelectric effect. Einstein's theory of light quanta received almost no support from other physicists for nearly 20 years. It contradicted the wave theory of light that underlay James Clerk Maxwell's equations for electromagnetic behavior. Even after experiments demonstrated that Einstein's equations for the photoelectric effect were splendidly accurate, his explanation was not accepted. In 1922, when he was awarded the Nobel Prize, and his work on photoelectricity was mentioned by name, most physicists thought that, while the equation was correct, the idea of light quanta was impossible.
1905's third paper introduced the special theory of relativity, a detailed analysis of the concepts of time, distance, mass and energy which omits the force of gravity. Some of the paper's core mathematical ideas had been introduced a year earlier by the Dutch physicist Hendrik Lorentz, but Einstein showed how to understand these mathematical oddities. His explanation arose from two axioms: one was Galileo's old idea that the laws of nature should be the same for all observers that move with constant speed relative to each other; and, two, that the speed of light is the same for every observer. Special relativity has several striking consequences since the absolute concepts of time and size are rejected. The theory came to be called "special theory of relativity" to distinguish it from his later theory of general relativity, which considers all observers to be equivalent.
A fourth paper published later that same year showed one further deduction from relativity's axioms. That deduction was the famous equation that rest energy (E) equals mass (m) times the square of the speed of light (c) squared. Einstein considered this equation to be of paramount importance because it showed that matter and energy are profoundly linked. The idea later proved invaluable at understanding how the Big Bang (which was a pure burst of energy) could lead to the precipitation of a universe filled with matter. More immediately, however, the equation set people to dreaming of explosive weaponry, although atomic bombs only became a practical possibility after nuclear physics had developed considerably beyond the few vague speculations of 1905. (Remember that before that year, even the existence of atoms was controversial.)
In November 1915 Einstein presented a series of lectures before the Prussian Academy of Sciences in which he described his theory of general relativity. The final lecture climaxed with his introduction of an equation that replaced Newton's law of gravity. This theory considers all observers to be equivalent, not only those moving at a uniform speed. In general relativity, gravity is no longer a force (as it was in Newton's law of gravity) but is a consequence of the curvature of space-time. The theory provided the foundation for the study of cosmology and gave scientists the tools for understanding many features of the universe that were not discovered until well after Einstein's death.
Einstein's relationship with quantum physics, is quite remarkable. He was the first, even before Max Planck, the discoverer of the quantum, to say that quantum theory was revolutionary. His idea of light quanta showed the revolutionary break with the classical understanding of physics. In 1909, Einstein presented his first paper to a gathering of physicists and told them that they must find some way to understand waves and particles together.
In the early 1920's, Einstein was the lead figure in a famous weekly physics colloquium at the University of Berlin.
However, in the mid-1920's, as the original quantum theory was replaced with a new quantum mechanics, Einstein balked at the Copenhagen interpretation of the new equations because it settled for a probabilistic, non-visualizable account of physical behavior. Einstein agreed that the theory was the best available, but he looked for an explantion that would be more "complete," i.e., deterministic. His belief that physics described the laws that govern "real things" had led to his successes with atoms, photons, and gravity. He was unwilling to abandon that faith.
Einstein's famous remark, "Quantum mechanics is certainly imposing. But an inner voice tells me it is not yet the real thing. The theory says a lot, but does not really bring us any closer to the secret of the Old One. I, at any rate, am convinced that he does not throw dice," appeared in a 1926 letter to Max Born. It was not a rejection of statistical theory. Einstein had used statistical analysis in his work on Brownian motion and photoelectricity. In papers published before the miracle year of 1905 he even discovered Gibbs ensembles on his own. But he did not believe that, at bottom, physical reality behaves randomly.
In 1914, just before the start of World War I, Einstein settled in Berlin. His pacifism and Jewish origins outraged German nationalists. After he became world famous (on November 7, 1919, when the London Times reported the success of his gravitational theory) nationalist hatred of him grew even more ferocious.
In 1933, after Adolf Hitler came to power, he settled in the United States and accepted a position at the Institute of Advanced Study in Princeton, New Jersey. He became an American citizen in 1940. He spent his last 20 years in an increasingly isolated and ultimately unsuccessful attempt at constructing a theory that would unify General Relativity and quantum mechanics. He died April 18, 1955 in Princeton, New Jersey.
Einstein considered himself a socialist. In a 1949 article, he described the "predatory phase of human development", exemplified by an anarchistic capitalist society, as a source of evil to be overcome. He disapproved of the totalitarian socialist regimes in the Soviet Union and elsewhere; nowadays, his position would probably be called social democratic.
Einstein first favored construction of the atomic bomb in order to defeat Hitler, and even signed an important letter alerting President Roosevelt to the fact that an atomic bomb was possible. But after the war he lobbied for nuclear disarmament and a world government.
He was offered the opportunity to become the first President of Israel but turned the offer down. His religious views were close to the pantheism of Baruch Spinoza: he believed that God revealed himself in the holy harmony of the laws of nature and he rejected a personal God able to interact with humans. He once said that among the major religions, he preferred Buddhism.
- S. Morgan Friedman, "Albert Einstein Online", http://www.westegg.com/einstein/. A comprehensive listing of online resources about Einstein.