A German-Swiss physicist and Nobel laureate, Einstein is best known for his special and general theories of relativity and for his bold hypothesis concerning the particle nature of light. He is widely viewed as the most famous scientist of the 20th century. He was born in Ulm, Württemberg, in March 1879.
As a youth in Munich, he showed an intense curiosity about nature and an ability to understand difficult mathematical concepts. In high school, he excelled in mathematics but failed utterly in the classics. At 16 Einstein moved away from his family to Switzerland, where his good performance in mathematics barely got him into a technical college in Zurich. He did not enjoy it and skipped most lectures, preferring to play his violin or to study physics in the library. He graduated in 1900 but his professors did not recommend him for a place in university. Instead, he secured a junior position in the patent office at Bern. In the year 1905 he published four papers, for which the year is named the "annus mirabilis":
1. The first paper, published June 9, dealt with the photoelectric effect and the nature of light; applying Planck's quantum theory, which had been proposed five years earlier and was quietly forgotten. The paper, "On a Heuristic Viewpoint Concerning the Production and Transformation of Light", proposed the idea of energy quanta. This paper won him the Nobel Prize in physics 16 years later.
2. The second article, published July 18, "On the Motion of Small Particles Suspended in a Stationary Liquid, as Required by the Molecular Kinetic Theory of Heat", offered a stochastic model of Brownian motion.
3. His third paper, published September 26, was “On the Electrodynamics of Moving Bodies” and had the most profound effect on modern physics. It contained Einstein's Special Theory of Relativity. Einstein proposed that it was meaningless to speak of one body moving and another body being still. Bodies can only be thought of as moving in relationship to each other. All motion is relative to some frame of reference, and the laws of nature apply unchanged, whatever that frame of reference. In particular, this means that the speed of electromagnetic radiation (such as light) is always the same, no matter the frame of reference. In subsequent years, results predicted on the basis of his theory were confirmed over and over again, and the Special Theory of Relativity eventually revolutionized how scientists viewed matter, space, time and all the things that interact with them.
4.On November 21, 1905, Annalen der Physik published a fourth paper, ("Does the Inertia of a Body Depend Upon Its Energy Content?"), in which Einstein developed an argument for arguably the most famous equation in the field of physics: E = mc2.
After the war ended, in 1919, scientists used a total eclipse of the sun to confirm that light from distant stars was indeed deflected as it passed through the influence of the sun's gravity, exactly as General Relativity predicted. Einstein became internationally renowned.
When Hitler took over as chancellor in 1933, he had been in California working as a visiting professor. Einstein's apartment in Berlin and his summer cottage in the country were raided, his papers confiscated, and his bank accounts closed.
Einstein was smart enough to get the message right away that he was unwelcome. He returned to Europe and handed in his German passport. He considered many offers, from places like Paris, Istanbul and Oxford, eventually deciding on Princeton, which offered him an attractive package teaching at its Institute for Advanced Study.
He had hesitations about Princeton. It had a secret quota system allowing only a small percentage of the incoming class to be Jewish. The Institute's director, Abraham Flexner, was worried that Einstein would be too directly involved in Jewish refugee causes, so he micromanaged Einstein's public appearances, trying to keep him out of the public eye. He even declined an invitation for Einstein to see FDR at the White House without telling the scientist. When Einstein found out, he personally called Eleanor Roosevelt and arranged for a visit anyway, and then complained about the incident in a letter to a rabbi friend of his, giving the return address as "Concentration Camp, Princeton."
In 1938, incoming freshmen at Princeton ranked Einstein as the second-greatest living person. First place went to Adolf Hitler.
(Thanks to Garrison Keillor and the Writer's Almanac, from which this is mostly adapted.)