Who Was Albert Einstein?

How did Einstein get from Ulm to the Bern patent office?

Albert Einstein was born in Ulm, in Württemberg, Germany, on March 14, 1879.^[1] He grew up in Munich, where his father founded an electrical engineering company.^[2] The family later moved to Italy, and Albert continued his schooling in Aarau, Switzerland, before entering the Swiss Federal Polytechnic School in Zurich in 1896 to train as a teacher of physics and mathematics.^[1]

After graduating with an undistinguished record, Einstein tried and failed to get a university job.^[5] Unable to find a teaching post, he became a technical assistant at the Swiss Patent Office, a job the American Institute of Physics (AIP) dates to 1902.^[1][5] He called it "a kind of salvation": the regular salary and the work of evaluating patent claims left him time to think about the most basic problems in physics.^[5] He did much of his important work in his spare time there.^[1] NobelPrize.org dates his University of Zurich doctorate to 1905; the AIP notes that the faculty approved it in July 1905 and formally awarded the degree in January 1906.^[1][3][5]

What did Einstein publish in his 1905 "miracle year"?

NobelPrize.org counts four landmark papers from 1905: on the photoelectric effect, Brownian motion, the special theory of relativity, and the equivalence of matter and energy, written E = mc².^[3] The Einstein Papers Project at Caltech singles out three masterpieces that appeared in quick succession in what it calls "Einstein's year of miracles".^[6]

• Light. He argued that light can behave as if it were made of separate particles of energy, which he called light quanta, and used the idea to explain how light knocks electrons out of metals.^[5]
• Brownian motion. He explained the random jittering of tiny particles in a liquid, long observed by biologists, as the result of bombardment by the liquid's invisible atoms.^[5]
• Special relativity. He showed that the principle of relativity could be made compatible with electromagnetic theory through a new analysis of space and time.^[5]
• E = mc². He found that if a body gives off energy, its mass must fall by a proportionate amount.^[5]

How did general relativity make Einstein famous?

After posts in Zurich and Prague, Einstein moved to Berlin in 1914.^[1] He arrived at the field equations of his general theory of relativity in 1915, and in 1916 he published a full account of the theory.^[5][3][1] The equations described gravity as the warping of space and time by matter, and Einstein tested them by correctly calculating a small, long-unexplained irregularity in the motion of the planet Mercury.^[5]

The theory predicted that starlight passing near the Sun should be slightly bent by gravity, which could be measured during an eclipse.^[5] British astronomers sent two expeditions to observe the total eclipse of May 1919, one to an island off West Africa and one to Brazil, and their photographs showed starlight deflected just as Einstein had predicted.^[5] The announcement caused a sensation far beyond science, and Einstein became the world's symbol of the new physics.^[5]

Why did Einstein's Nobel Prize not mention relativity?

Einstein received the Nobel Prize in Physics for 1921 "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect".^[2] The citation does not name relativity.^[2] The 1921 physics prize had been reserved, as the statutes allow, so it was awarded the following year and announced on November 9, 1922.^[3]

At the ceremony on December 10, 1922, which Einstein could not attend, Professor S. Arrhenius, chairman of the Nobel Committee for Physics, said most discussion of Einstein centred on relativity.^[3][4] He called it a subject of lively debate among philosophers, with astrophysical implications still being rigorously examined.^[4] The prize, he said, was given in particular for Einstein's work in quantum theory, and his law of the photoelectric effect had passed rigorous tests by the American Millikan and his students.^[4]

Einstein had explained that light consists of packets of energy called quanta, and that a single quantum, a photon, must have a certain minimum frequency to free an electron.^[2] The effect is the basis for devices such as photodiodes, which are used in solar cells and imaging.^[3]

Why did Einstein leave Germany for Princeton?

In 1920, Einstein and his theory of relativity came under public attack from anti-Semites.^[5] He had become a German citizen in 1914, but in 1933, the year the Nazis came to power, he renounced that citizenship for political reasons and settled in the United States.^[1][5] He worked at the Institute for Advanced Study in Princeton, New Jersey, became a U.S. citizen in 1940 and retired in 1945.^[1][2]

Did Einstein help build the atomic bomb?

In August 1939, after the discovery of uranium fission, his friend Leo Szilard and other physicists feared that Nazi Germany might build uranium bombs and came to Einstein for political help.^[5] The resulting letter to President Franklin D. Roosevelt, dated August 2, 1939, was a collaboration between Einstein, Szilard and the economist Alexander Sachs.^[7] It warned that foreign governments might use a uranium chain reaction to create a weapon and recommended quick action on American nuclear research.^[7] Sachs delivered it on October 11, 1939, and it is credited with launching what became the Manhattan Project.^[7]

Einstein played no other role in the bomb project and was denied security clearance for such work, though he served as a wartime consultant to the U.S. Navy's Bureau of Ordnance.^[5] In words recounted by Linus Pauling and dated November 16, 1954, Einstein called signing the letter "one great mistake" in his life, while adding that there was "some justification": the danger that the Germans would make atomic bombs.^[8]

From May 1946 he chaired the Emergency Committee of Atomic Scientists and appealed for nuclear disarmament.^[5] In 1952 he declined an offer to become President of Israel.^[5] Einstein died in Princeton, New Jersey, on April 18, 1955, and an unfinished speech for the anniversary of Israel's independence was found at his bedside.^[1][5]