Albert Einstein ( EYEN-styne; German: 14 March 1879 – 18 April 1955) was a German-born theoretical physicist who developed the theory of relativity, one of the two pillars of modern physics (alongside quantum mechanics).

He received the 1921 Nobel Prize in Physics "for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect", a pivotal step in the development of quantum theory.

The son of a salesman who later operated an electrochemical factory, Einstein was born in the German Empire, but moved to Switzerland in 1895, forsaking his German citizenship the following year.

Specializing in physics and mathematics, he received his academic teaching diploma from the Swiss Federal Polytechnic School in Zürich in 1900.

After initially struggling to find work, from 1902 to 1909 he was employed as a patent examiner at the Swiss Patent Office in Bern.

In 1905, called his annus mirabilis ('miracle year'), he published four groundbreaking papers which attracted the attention of the academic world; the first paper outlined the theory of the photoelectric effect, the second explained Brownian motion, the third introduced special relativity, and the fourth mass–energy equivalence.

He was invited to teach theoretical physics at the University of Bern in 1908 and the following year moved to the University of Zurich, then in 1911 to Charles University in Prague before returning to ETH (the newly renamed Federal Polytechnic School) in Zürich in 1912.

In 1914, he was elected to the Prussian Academy of Sciences in Berlin, where he remained for 19 years.

Soon after publishing his work on special relativity, Einstein began working to extend the theory to gravitational fields; he then published a paper on general relativity in 1916, introducing his theory of gravitation.

In 1917, he applied the general theory of relativity to model the structure of the universe.

In 1933, while Einstein was visiting the United States, Adolf Hitler came to power.

He settled in the United States and became an American citizen in 1940.

Einstein was affiliated with the Institute for Advanced Study in Princeton, New Jersey, until his death in 1955.

Albert Einstein was born in Ulm, in the Kingdom of Württemberg in the German Empire, on 14 March 1879.

In 1880, the family moved to Munich, where Einstein's father and his uncle Jakob founded Elektrotechnische Fabrik J. Einstein & Cie, a company that manufactured electrical equipment based on direct current.

In 1894, Hermann and Jakob's company lost a bid to supply the city of Munich with electrical lighting because they lacked the capital to convert their equipment from the direct current (DC) standard to the more efficient alternating current (AC) standard.

At the end of December 1894, he traveled to Italy to join his family in Pavia, convincing the school to let him go by using a doctor's note.

On the advice of the principal of the polytechnic school, he attended the Argovian cantonal school (gymnasium) in Aarau, Switzerland, in 1895 and 1896 to complete his secondary schooling.

In January 1896, with his father's approval, Einstein renounced his citizenship in the German Kingdom of Württemberg to avoid military service.

In September 1896, he passed the Swiss Matura with mostly good grades, including a top grade of 6 in physics and mathematical subjects, on a scale of 1–6.

In 1900, Einstein passed the exams in Maths and Physics and was awarded the Federal teaching diploma.

There is eyewitness evidence and several letters over many years that indicate Marić might have collaborated with Einstein prior to his 1905 papers, known as the Annus Mirabilis papers, and that they developed some of the concepts together during their studies, although some historians of physics who have studied the issue disagree that she made any substantive contributions.

Early correspondence between Einstein and Marić was discovered and published in 1987 which revealed that the couple had a daughter named "Lieserl", born in early 1902 in Novi Sad where Marić was staying with her parents.

The contents of Einstein's letter in September 1903 suggest that the girl was either given up for adoption or died of scarlet fever in infancy.

Einstein and Marić married in January 1903.

In May 1904, their son Hans Albert Einstein was born in Bern, Switzerland.

Their son Eduard was born in Zürich in July 1910.

The couple moved to Berlin in April 1914, but Marić returned to Zürich with their sons after learning that despite their close relationship before, Einstein's chief romantic attraction was now his cousin Elsa Löwenthal; she was his first cousin maternally and second cousin paternally.

They divorced on 14 February 1919, having lived apart for five years.

In letters revealed in 2015, Einstein wrote to his early love Marie Winteler about his marriage and his strong feelings for her.

He wrote in 1910, while his wife was pregnant with their second child: "I think of you in heartfelt love every spare minute and am so unhappy as only a man can be."

Einstein married Elsa Löwenthal in 1919, after having a relationship with her since 1912.

They emigrated to the United States in 1933.

Elsa was diagnosed with heart and kidney problems in 1935 and died in December 1936.In 1923, Einstein fell in love with a secretary named Betty Neumann, the niece of a close friend, Hans Mühsam.

In a volume of letters released by Hebrew University of Jerusalem in 2006, Einstein described about six women, including Margarete Lebach (a blonde Austrian), Estella Katzenellenbogen (the rich owner of a florist business), Toni Mendel (a wealthy Jewish widow) and Ethel Michanowski (a Berlin socialite), with whom he spent time and from whom he received gifts while being married to Elsa.

After graduating in 1900, Einstein spent almost two frustrating years searching for a teaching post.

He acquired Swiss citizenship in February 1901, but for medical reasons was not conscripted.

With a few friends he had met in Bern, Einstein started a small discussion group in 1902, self-mockingly named "The Olympia Academy", which met regularly to discuss science and philosophy.

In 1900, Einstein's paper "Folgerungen aus den Capillaritätserscheinungen" ("Conclusions from the Capillarity Phenomena") was published in the journal Annalen der Physik.

On 30 April 1905, Einstein completed his thesis, with Alfred Kleiner, Professor of Experimental Physics, serving as pro-forma advisor.

Also in 1905, which has been called Einstein's annus mirabilis (amazing year), he published four groundbreaking papers, on the photoelectric effect, Brownian motion, special relativity, and the equivalence of mass and energy, which were to bring him to the notice of the academic world, at the age of 26.

By 1908, he was recognized as a leading scientist and was appointed lecturer at the University of Bern.

Einstein was appointed associate professor in 1909.Einstein became a full professor at the German Charles-Ferdinand University in Prague in April 1911, accepting Austrian citizenship in the Austro-Hungarian Empire to do so.

In July 1912, he returned to his alma mater in Zürich.

From 1912 until 1914, he was a professor of theoretical physics at the ETH Zurich, where he taught analytical mechanics and thermodynamics.

On 3 July 1913, he was voted for membership in the Prussian Academy of Sciences in Berlin.

He joined the academy and thus Berlin University on 1 April 1914.

The institute was established on 1 October 1917, with Einstein as its director.

In 1916, Einstein was elected president of the German Physical Society (1916–1918).

Based on calculations Einstein had made in 1911 using his new theory of general relativity, light from another star should be bent by the Sun's gravity.

In 1919, that prediction was confirmed by Sir Arthur Eddington during the solar eclipse of 29 May 1919.

On 7 November 1919, the leading British newspaper The Times printed a banner headline that read: "Revolution in Science – New Theory of the Universe – Newtonian Ideas Overthrown".

In 1920, he became a Foreign Member of the Royal Netherlands Academy of Arts and Sciences.

In 1922, he was awarded the 1921 Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect".

While the general theory of relativity was still considered somewhat controversial, the citation also does not treat even the cited photoelectric work as an explanation but merely as a discovery of the law, as the idea of photons was considered outlandish and did not receive universal acceptance until the 1924 derivation of the Planck spectrum by S. N. Bose.

Einstein was elected a Foreign Member of the Royal Society (ForMemRS) in 1921.

He also received the Copley Medal from the Royal Society in 1925.

Einstein visited New York City for the first time on 2 April 1921, where he received an official welcome by Mayor John Francis Hylan, followed by three weeks of lectures and receptions.

He also published an essay, "My First Impression of the U.S.A.", in July 1921, in which he tried briefly to describe some characteristics of Americans, much as had Alexis de Tocqueville, who published his own impressions in Democracy in America (1835).

In his own travel diaries from his 1922–23 visit to Asia, he expresses some views on the Chinese, Japanese and Indian people, which have been described as xenophobic and racist judgments when they were rediscovered in 2018.Because of Einstein's travels to the Far East, he was unable to personally accept the Nobel Prize for Physics at the Stockholm award ceremony in December 1922.

Einstein visited Spain for two weeks in 1923, where he briefly met Santiago Ramón y Cajal and also received a diploma from King Alfonso XIII naming him a member of the Spanish Academy of Sciences.

From 1922 to 1932, Einstein was a member of the International Committee on Intellectual Cooperation of the League of Nations in Geneva (with a few months of interruption in 1923–1924), a body created to promote international exchange between scientists, researchers, teachers, artists and intellectuals.

In December 1930, Einstein visited America for the second time, originally intended as a two-month working visit as a research fellow at the California Institute of Technology.

In February 1933, while on a visit to the United States, Einstein knew he could not return to Germany with the rise to power of the Nazis under Germany's new chancellor, Adolf Hitler.

While at American universities in early 1933, he undertook his third two-month visiting professorship at the California Institute of Technology in Pasadena.

In April 1933, Einstein discovered that the new German government had passed laws barring Jews from holding any official positions, including teaching at universities.

In late July 1933, he went to England for about six weeks at the personal invitation of British naval officer Commander Oliver Locker-Lampson, who had become friends with Einstein in the preceding years.

Einstein later contacted leaders of other nations, including Turkey's Prime Minister, İsmet İnönü, to whom he wrote in September 1933 requesting placement of unemployed German-Jewish scientists.

In October 1933, Einstein returned to the US and took up a position at the Institute for Advanced Study, noted for having become a refuge for scientists fleeing Nazi Germany.

At the time, most American universities, including Harvard, Princeton and Yale, had minimal or no Jewish faculty or students, as a result of their Jewish quotas, which lasted until the late 1940s.

He had offers from several European universities, including Christ Church, Oxford where he stayed for three short periods between May 1931 and June 1933 and was offered a 5-year studentship, but in 1935, he arrived at the decision to remain permanently in the United States and apply for citizenship.

Einstein's affiliation with the Institute for Advanced Study would last until his death in 1955.

In 1939, a group of Hungarian scientists that included émigré physicist Leó Szilárd attempted to alert Washington to ongoing Nazi atomic bomb research.

To make certain the US was aware of the danger, in July 1939, a few months before the beginning of World War II in Europe, Szilárd and Wigner visited Einstein to explain the possibility of atomic bombs, which Einstein, a pacifist, said he had never considered.

In 1954, a year before his death, Einstein said to his old friend, Linus Pauling, "I made one great mistake in my life—when I signed the letter to President Roosevelt recommending that atom bombs be made; but there was some justification—the danger that the Germans would make them ..."

In 1955, Einstein and ten other intellectuals and scientists, including British philosopher Bertrand Russell, signed a manifesto highlighting the danger of nuclear weapons.

Einstein became an American citizen in 1940.

As part of his involvement, he corresponded with civil rights activist W. E. B. Du Bois and was prepared to testify on his behalf during his trial in 1951.

In 1946 Einstein visited Lincoln University in Pennsylvania, a historically black college, where he was awarded an honorary degree.

Einstein was a figurehead leader in helping establish the Hebrew University of Jerusalem, which opened in 1925 and was among its first Board of Governors.

Earlier, in 1921, he was asked by the biochemist and president of the World Zionist Organization, Chaim Weizmann, to help raise funds for the planned university.

Upon his death while in office in November 1952 and at the urging of Ezriel Carlebach, Prime Minister David Ben-Gurion offered Einstein the position of President of Israel, a mostly ceremonial post.

He is sometimes erroneously credited as the editor of the 1937 edition of the Köchel catalog of Mozart's work; that edition was prepared by Alfred Einstein, who may have been a distant relation.

In 1931, while engaged in research at the California Institute of Technology, he visited the Zoellner family conservatory in Los Angeles, where he played some of Beethoven and Mozart's works with members of the Zoellner Quartet.

In 1918, Einstein was one of the founding members of the German Democratic Party, a liberal party.

In 1925, he criticized them for not having a 'well-regulated system of government' and called their rule a 'regime of terror and a tragedy in human history'.

He later adopted a more balanced view, criticizing their methods but praising them, which is shown by his 1929 remark on Vladimir Lenin:

The FBI created a secret dossier on Einstein in 1932, and by the time of his death his FBI file was 1,427 pages long.

In a German-language letter to philosopher Eric Gutkind, dated 3 January 1954, Einstein wrote:The word God is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honorable, but still primitive legends which are nevertheless pretty childish.

On 17 April 1955, Einstein experienced internal bleeding caused by the rupture of an abdominal aortic aneurysm, which had previously been reinforced surgically by Rudolph Nissen in 1948.

In a memorial lecture delivered on 13 December 1965, at UNESCO headquarters, nuclear physicist J. Robert Oppenheimer summarized his impression of Einstein as a person: "He was almost wholly without sophistication and wholly without worldliness ...

On 5 December 2014, universities and archives announced the release of Einstein's papers, comprising more than 30,000 unique documents.

The Annus Mirabilis papers are four articles pertaining to the photoelectric effect (which gave rise to quantum theory), Brownian motion, the special theory of relativity, and E = mc2 that Einstein published in the Annalen der Physik scientific journal in 1905.

Einstein's first paper submitted in 1900 to Annalen der Physik was on capillary attraction.

It was published in 1901 with the title "Folgerungen aus den Capillaritätserscheinungen", which translates as "Conclusions from the capillarity phenomena".

These papers were the foundation for the 1905 paper on Brownian motion, which showed that Brownian movement can be construed as firm evidence that molecules exist.

His research in 1903 and 1904 was mainly concerned with the effect of finite atomic size on diffusion phenomena.

Einstein's "Zur Elektrodynamik bewegter Körper" ("On the Electrodynamics of Moving Bodies") was received on 30 June 1905 and published 26 September of that same year.

Einstein's 1905 work on relativity remained controversial for many years, but was accepted by leading physicists, starting with Max Planck.

In 1908, Hermann Minkowski reinterpreted special relativity in geometric terms as a theory of spacetime.

Einstein adopted Minkowski's formalism in his 1915 general theory of relativity.

Consequently, in 1907 he published an article on acceleration under special relativity.

In 1911, Einstein published another article "On the Influence of Gravitation on the Propagation of Light" expanding on the 1907 article, in which he estimated the amount of deflection of light by massive bodies.

In 1916, Einstein predicted gravitational waves, ripples in the curvature of spacetime which propagate as waves, traveling outward from the source, transporting energy as gravitational radiation.

Einstein's prediction was confirmed on 11 February 2016, when researchers at LIGO published the first observation of gravitational waves, detected on Earth on 14 September 2015, nearly one hundred years after the prediction.

After more than two years of intensive work, Einstein realized that the hole argument was mistaken and abandoned the theory in November 1915.

In 1917, Einstein applied the general theory of relativity to the structure of the universe as a whole.

Following the discovery of the recession of the nebulae by Edwin Hubble in 1929, Einstein abandoned his static model of the universe, and proposed two dynamic models of the cosmos, The Friedmann-Einstein universe of 1931 and the Einstein–de Sitter universe of 1932.

In late 2013, a team led by the Irish physicist Cormac O'Raifeartaigh discovered evidence that, shortly after learning of Hubble's observations of the recession of the nebulae, Einstein considered a steady-state model of the universe.

In a hitherto overlooked manuscript, apparently written in early 1931, Einstein explored a model of the expanding universe in which the density of matter remains constant due to a continuous creation of matter, a process he associated with the cosmological constant.

The use of non-covariant objects like pseudotensors was heavily criticized in 1917 by Erwin Schrödinger and others.

In 1935, Einstein collaborated with Nathan Rosen to produce a model of a wormhole, often called Einstein–Rosen bridges.

This modification was made by Einstein and Cartan in the 1920s.

In a 1905 paper, Einstein postulated that light itself consists of localized particles (quanta).

This idea only became universally accepted in 1919, with Robert Millikan's detailed experiments on the photoelectric effect, and with the measurement of Compton scattering.

In 1907, Einstein proposed a model of matter where each atom in a lattice structure is an independent harmonic oscillator.

Throughout the 1910s, quantum mechanics expanded in scope to cover many different systems.

Einstein contributed to these developments by linking them with the 1898 arguments Wilhelm Wien had made.

Einstein noted in 1911 that the same adiabatic principle shows that the quantity which is quantized in any mechanical motion must be an adiabatic invariant.

In 1924, Einstein received a description of a statistical model from Indian physicist Satyendra Nath Bose, based on a counting method that assumed that light could be understood as a gas of indistinguishable particles.

It was not until 1995 that the first such condensate was produced experimentally by Eric Allin Cornell and Carl Wieman using ultra-cooling equipment built at the NIST–JILA laboratory at the University of Colorado at Boulder.

Although the patent office promoted Einstein to Technical Examiner Second Class in 1906, he had not given up on academia.

In 1908, he became a Privatdozent at the University of Bern.

This paper introduced the photon concept (although the name photon was introduced later by Gilbert N. Lewis in 1926) and inspired the notion of wave–particle duality in quantum mechanics.

In a series of works completed from 1911 to 1913, Planck reformulated his 1900 quantum theory and introduced the idea of zero-point energy in his "second quantum theory".

In 1917, at the height of his work on relativity, Einstein published an article in Physikalische Zeitschrift that proposed the possibility of stimulated emission, the physical process that makes possible the maser and the laser.

This paper would inspire Schrödinger's work of 1926.

Einstein played a major role in developing quantum theory, beginning with his 1905 paper on the photoelectric effect.

However, he became displeased with modern quantum mechanics as it had evolved after 1925, despite its acceptance by other physicists.

In 1935, Einstein returned to quantum mechanics, in particular to the question of its completeness, in the "EPR paper".

But as a physical principle, local realism was shown to be incorrect when the Aspect experiment of 1982 confirmed Bell's theorem, which J. S. Bell had delineated in 1964.

In 1950, he described his "unified field theory" in a Scientific American article titled "On the Generalized Theory of Gravitation".

In 1926, Einstein and his former student Leó Szilárd co-invented (and in 1930, patented) the Einstein refrigerator.

On 11 November 1930, U.S. Patent 1,781,541 was awarded to Einstein and Leó Szilárd for the refrigerator.

Margot Einstein permitted the personal letters to be made available to the public, but requested that it not be done until twenty years after her death (she died in 1986).

Barbara Wolff, of the Hebrew University's Albert Einstein Archives, told the BBC that there are about 3,500 pages of private correspondence written between 1912 and 1955.Corbis, successor to The Roger Richman Agency, licenses the use of his name and associated imagery, as agent for the university.

The Einstein rights were litigated in 2015 in a federal district court in California.

Einstein received numerous awards and honors, and in 1922, he was awarded the 1921 Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect".

None of the nominations in 1921 met the criteria set by Alfred Nobel, so the 1921 prize was carried forward and awarded to Einstein in 1922.

Albert Einstein on Nobelprize.org including the Nobel Lecture 11 July 1923 Fundamental ideas and problems of the theory of relativity Albert Einstein, videos on History.com "

Archived from the original on 8 June 2011.