Albert Einstein



Albert Einstein

The American career of Albert Einstein

When Adolf Hitler came to power in January 1933, Einstein was a guest professor at Princeton University, a position that he took in December 1932, after an invitation from the American educator, Abraham Flexner. Einstein stayed in the United States, where he was given permanent residency. He accepted a position at the newly founded Institute for Advanced Study in Princeton Township, New Jersey.

In 1939, under the encouragement of Szilárd, Einstein sent a letter to President Franklin Delano Roosevelt urging the study of nuclear fission for military purposes. This was done under fears that the Nazi government would be first to develop atomic weapons. Roosevelt started a small investigation into the matter, which eventually became the massive Manhattan Project.

General Relativity

In November 1915, Einstein presented a series of lectures before the Prussian Academy of Sciences in which he described his theory of gravity, known as general relativity. The final lecture climaxed with his introduction of an equation that replaced Newton's law of gravity, Einstein's Field Equations. This was really the defining moment in the career of Albert Einstein.

Initially, scientists were skeptical because the general theory of relativity was not derived by experiment or observation, but by pure mathematical reasoning and rational analysis. After the 1919 confirmation of the prediction of how much the light from a star will be bent by the Sun's gravity when it passed close to the Sun, acceptance increased dramatically (Pais, 1982). 

Quantum Physics

In 1917, Einstein published "On the Quantum Mechanics of Radiation". This article introduced the concept of stimulated emission, the physical principle that allows light amplification in the laser (Pais, 1994). He also published a paper that year that used the general theory of relativity to model the behavior of the entire universe, setting the stage for modern cosmology. In this work he created his self-described "worst blunder", the cosmological constant.

In the mid-1920s the original quantum theory was replaced with a new theory of quantum mechanics. Einstein balked at the Copenhagen interpretation of the new equations, either because it settled for a probabilistic, non-visualizable account of physical behavior, or because it described matter as being in necessarily contradictory states (Parker, 2000).

Einstein agreed that the theory was the best available, but he looked for a more "complete" explanation, i.e., more deterministic. He could not abandon the belief that physics described the laws that govern "real things", the belief which had led ...