Theory of Relativity

In November, 1915, Einstein completed the general theory of relativity, which he considered his masterpiece. He was convinced that general relativity was correct because of its mathematical beauty and because it accurately predicted the perihelion of Mercury's orbit around the sun, which fell short in Newton’s theory. General relativity theory also predicted a measurable deflection of light around the sun when a planet or another sun oribited near the sun. That prediction was confirmed in observations by British astronomer Sir Arthur Eddington during the solar eclipse of 1919. In 1921, Albert Einstein received word that he had received the Nobel Prize for Physics. Because relativity was still considered controversial, Einstein received the award for his explanation of the photoelectric effect.

In the 1920s, Einstein launched the new science of cosmology. His equations predicted that the universe is dynamic, ever expanding or contracting. This contradicted the prevailing view that the universe was static, a view that Einstein held earlier and was a guiding factor in his development of the general theory of relativity. But his later calculations in the general theory indicated that the universe could be expanding or contracting. In 1929, astronomer Edwin Hubble found that the universe was indeed expanding, thereby confirming Einstein's work. In 1930, during a visit to the Mount Wilson Observatory near Los Angeles, Einstein met with Hubble and declared the cosmological constant, his original theory of the static size and shape of the universe, to be his "greatest blunder."

While Einstein was touring much of the world speaking on his theories in the 1920s, the Nazis were rising to power under the leadership of Adolph Hitler. Einstein’s theories on relativity became a convenient target for Nazi propaganda. In 1931, the Nazi’s enlisted other physicists to denounce Einstein and his theories as "Jewish physics." At this time, Einstein learned that the new German government, now in full control by the Nazi party, had passed a law barring Jews from holding any official position, including teaching at universities. Einstein also learned that his name was on a list of assassination targets, and a Nazi organization published a magazine with Einstein's picture and the caption "Not Yet Hanged" on the cover.