Nazi backlash and coming to America
Einstein’s popularity and the overwhelming success of his theories generated a backlash. The rising Nazi movement found a convenient target in relativity, calling it “Jewish physics” and sponsoring lectures and burning books to denounce Einstein and his theories. The Nazis recruited other physicists, including Nobel laureates Philipp Lenard and Johannes Stark, to unmask Einstein. One Hundred Authors Against Einstein was published in 1931. When asked by many scientists to comment on this accusation of relativity, Einstein replied that in order to defeat relativity, one did not need words. Said by 100 scientists, just one truth.
In December 1932, Einstein decided to leave Germany permanently. Einstein became clear that his life was in danger. A Nazi organization published a magazine with Einstein’s photo and the caption “Not hanged” on the cover. There’s even an award on his head. The threat was so great that Einstein distanced himself from his pacifist friends and declared that it was justifiable to defend himself with weapons against Nazi aggression. For Einstein, pacifism was not an absolute concept but one that needed to be re-examined depending on the magnitude of the threat.
Einstein settled at the newly formed Institute for Advanced Study at Princeton, New Jersey, which soon became a mecca for physicists from around the world. Newspaper articles declared that the “pope of physics” had left Germany and that Princeton had become the new Vatican.
Personal sorrow, World War II, and the atomic bomb
The 1930s were difficult years for Einstein. His son, Eduard, was diagnosed with schizophrenia and suffered a nervous breakdown in 1930. (Eduard would be put into administration for the rest of his life.) Einstein’s close friend, homemaker. physicist Paul Ehrenfest, who helped develop the theory of general relativity, committed suicide in 1933. And Einstein’s beloved wife, Elsa, died in 1936.
In July 1939, physicist Leo Szilard convinced Einstein that he should send a letter to US President Franklin D. Roosevelt urging him to develop an atomic bomb. With Einstein’s advice, Szilard drafted a letter on August 2 that Einstein signed, and the document was passed on to Roosevelt on October 11 by one of his economic advisers, Alexander Sachs. replied on October 19, informing Einstein that he had organized the Uranium Committee to study the matter
Einstein was granted permanent residency in the United States in 1935 and became an American citizen in 1940, although he chose to retain his Swiss citizenship. During the war Einstein’s colleagues were asked to journey to the desert town of Los Alamos, New Mexico, to develop the first atomic bomb for the Manhattan Project. Einstein, the man whose equation had set the whole effort into motion, was never asked to participate. Voluminous declassified Federal Bureau of Investigation (FBI) files, numbering several thousand, reveal the reason: the U.S. government feared Einstein’s lifelong association with peace and socialist organizations. (FBI director J. Edgar Hoover went so far as to recommend that Einstein be kept out of America by the Alien Exclusion Act, but he was overruled by the U.S. State Department.) Instead, during the war Einstein was asked to help the U.S. Navy evaluate designs for future weapons systems. Einstein also helped the war effort by auctioning off priceless personal manuscripts. In particular, a handwritten copy of his 1905 paper on special relativity was sold for $6.5 million.
Einstein was on vacation when he heard the news that an atomic bomb had been dropped on Japan. Almost immediately he was part of an international effort to try to bring the atomic bomb under control, forming the Emergency Committee of Atomic Scientists.
The physics community split on the question of whether to build a hydrogen bomb. J. Robert Oppenheimer, the director of the atomic bomb project, was stripped of his security clearance for having suspected leftist associations. Einstein backed Oppenheimer and opposed the development of the hydrogen bomb, instead calling for international controls on the spread of nuclear technology. Einstein also was increasingly drawn to antiwar activities and to advancing the civil rights of African Americans.
Increasing professional isolation and death
Although Einstein continued to pioneer many key developments in the theory of general relativity—such as wormholes, higher dimensions, the possibility of time travel, the existence of black holes, and the creation of the universe—he was increasingly isolated from the rest of the physics community. Because of the huge strides made by quantum theory in unraveling the secrets of atoms and molecules, the majority of physicists were working on the quantum theory, not relativity. In fact, Einstein would engage in a series of historic private debates with Niels Bohr, originator of the Bohr atomic model. Through a series of sophisticated “thought experiments,” Einstein tried to find logical inconsistencies in the quantum theory, particularly its lack of a deterministic mechanism. Einstein would often say that “God does not play dice with the universe.”
The other reason for Einstein’s increasing detachment from his colleagues was his obsession, beginning in 1925, with discovering a unified field theory—an all-embracing theory that would unify the forces of the universe, and thereby the laws of physics, into one framework. In his later years he stopped opposing the quantum theory and tried to incorporate it, along with light and gravity, into a larger unified field theory. Gradually Einstein became set in his ways. He rarely traveled far, confining himself to long walks around Princeton with close associates, whom he engaged in deep conversations about politics, religion, physics, and his unified field theory. In 1950 he published an article on his theory in Scientific American, but because it neglected the still-mysterious strong force, it was necessarily incomplete. When he died five years later of an aortic aneurysm, it was still unfinished.
Legacy of Albert Einstein
In some sense, Einstein, instead of being a relic, may have been too far ahead of his time. The strong force, a major piece of any unified field theory, was still a total mystery in Einstein’s lifetime. Only in the 1970s and ’80s did physicists begin to unravel the secret of the strong force with the quark model. Nevertheless, Einstein’s work continues to win Nobel Prizes for succeeding physicists. In 1993 a Nobel Prize was awarded to the discoverers of gravitation waves, predicted by Einstein. In 1995 a Nobel Prize was awarded to the discoverers of Bose-Einstein condensates (a new form of matter that can occur at extremely low temperatures). Known black holes now number in the thousands. New generations of space satellites have continued to verify the cosmology of Einstein. And many leading physicists are trying to finish Einstein’s ultimate dream of a “theory of everything.”
Einstein wrote the space-time entry for the 13th edition of the Encyclopædia Britannica. (See the Britannica Classic: Space-Time.)