Einstein

Einstein in 1947.
Born March 14, 1879
Ulm, Württemberg, Germany
Died April 18, 1955 (aged 76)
Princeton, New Jersey, USA
Residence Germany, Italy, Switzerland, USA
Citizenship German (1879–96, 1914–33)
Swiss (1901–55)
American (1940–55)
Ethnicity Ashkenazi Jewish
Fields Physicist
Institutions Swiss Patent Office (Berne)
University of Zurich
Charles University, Prague
Prussian Academy of Sciences
Kaiser Wilhelm Institute
University of Leiden
Institute for Advanced Study
Alma mater ETH Zurich
University of Zurich
Doctoral advisor Alfred Kleiner
Other academic advisors Heinrich Friedrich Weber
Known for General relativity
Special relativity
Brownian motion
Photoelectric effect
Mass-energy equivalence
Einstein field equations
Unified Field Theory
Bose–Einstein statistics
EPR paradox
Influences Marcel Grossmann
Influenced David Bohm
Notable awards Nobel Prize in Physics (1921)
Copley Medal (1925)
Max Planck Medal (1929)
Signature




Youth and schooling


Albert Einstein was born into a Jewish family in Ulm, Württemberg, Germany on March 14, 1879. His father was Hermann Einstein, a salesman and engineer. His mother was Pauline Einstein (née Koch). In 1880, the family moved to Munich, where his father and his uncle founded a company, Elektrotechnische Fabrik J. Einstein & Cie, that manufactured electrical equipment.
The Einsteins were not observant of Jewish religious practices, and Albert attended a Catholic elementary school. Although Einstein had early speech difficulties, he was a top student in elementary school.[5][6]


Albert Einstein in 1893 (age 14), taken before the family moved to Italy

When Einstein was five, his father showed him a pocket compass. Einstein realized that something in empty space was moving the needle and later stated that this experience made "a deep and lasting impression".[7] At his mother's insistence, he took violin lessons starting at age six, and although he disliked them and eventually quit, he later took great pleasure in Mozart's violin sonatas. As he grew, Einstein built models and mechanical devices for fun, and began to show a talent for mathematics.
In 1889, family friend Max Talmud, a medical student,[8] introduced the ten-year-old Einstein to key science, mathematics, and philosophy texts, including Kant's Critique of Pure Reason and Euclid's Elements (Einstein called it the "holy little geometry book").[8] From Euclid, Einstein began to understand deductive reasoning, and by the age of twelve, he had learned Euclidean geometry. Soon thereafter he began to investigate calculus.

In his early teens, Einstein attended the progressive Luitpold Gymnasium. His father intended for him to pursue electrical engineering, but Einstein clashed with authorities and resented the school regimen. He later wrote that the spirit of learning and creative thought were lost in strict rote learning.

In 1894, when Einstein was fifteen, his father's business failed, and the Einstein family moved to Italy, first to Milan and then, after a few months, to Pavia. During this time, Einstein wrote his first scientific work, "The Investigation of the State of Aether in Magnetic Fields".[9] Einstein had been left behind in Munich to finish high school, but in the spring of 1895, he withdrew to join his family in Pavia, convincing the school to let him go by using a doctor's note.

Rather than completing high school, Einstein decided to apply directly to the ETH Zurich, the Swiss Federal Institute of Technology in Zürich, Switzerland. Lacking a school certificate, he was required to take an entrance examination, which he did not pass, although he got exceptional marks in mathematics and physics.[10] Einstein wrote that it was in that same year, at age 16, that he first performed his famous thought experiment visualizing traveling alongside a beam of light (Einstein 1979).

The Einsteins sent Albert to Aarau, Switzerland to finish secondary school. While lodging with the family of Professor Jost Winteler, he fell in love with the family's daughter, Marie. (Albert's sister Maja later married Paul Winteler.)[11][12] In Aarau, Einstein studied Maxwell's electromagnetic theory. In 1896, he graduated at age 17, renounced his German citizenship to avoid military service (with his father's approval), and finally enrolled in the mathematics program at ETH. Marie moved to Olsberg, Switzerland for a teaching post.

In 1896, Einstein's future wife, Mileva Marić, also enrolled at ETH, as the only woman studying mathematics. During the next few years, Einstein and Marić's friendship developed into romance. Einstein graduated in 1900 from ETH with a degree in physics.[13] That same year, Einstein's friend Michele Besso introduced him to the work of Ernst Mach. The next year, Einstein published a paper in the prestigious Annalen der Physik on the capillary forces of a straw (Einstein 1901). On February 21, 1901, he gained Swiss citizenship, which he never revoked.
Patent office


The 'Einsteinhaus' in Berne where Einstein lived with Mileva on the first floor during his Annus Mirabilis

Following graduation, Einstein could not find a teaching post. After almost two years of searching, a former classmate's father helped him get a job in Berne, at the Federal Office for Intellectual Property,[15] the patent office, as an assistant examiner. His responsibility was evaluating patent applications for electromagnetic devices. In 1903, Einstein's position at the Swiss Patent Office was made permanent, although he was passed over for promotion until he "fully mastered machine technology".[16]
With friends he met in Bern, Einstein formed a weekly discussion club on science and philosophy, jokingly named "The Olympia Academy". Their readings included Poincaré, Mach, and Hume, who influenced Einstein's scientific and philosophical outlook.[17]

During this period Einstein had almost no personal contact with the physics community.[18] Much of his work at the patent office related to questions about transmission of electric signals and electrical-mechanical synchronization of time: two technical problems that show up conspicuously in the thought experiments that eventually led Einstein to his radical conclusions about the nature of light and the fundamental connection between space and time.[16][17]
Marriage and family life
Einstein and Mileva Marić had a daughter, Lieserl Einstein, born in early 1902.[19] Her fate is unknown.

Einstein married Mileva on January 6, 1903, although Einstein's mother had objected to the match because she had a prejudice against Serbs and thought Marić "too old" and "physically defective."[20] [21] Their relationship was for a time a personal and intellectual partnership. In a letter to her, Einstein called Marić "a creature who is my equal and who is as strong and independent as I am."[22] There has been debate about whether Marić influenced Einstein's work; however, most historians do not think she made major contributions.[23][24][25] On May 14, 1904, Albert and Mileva's first son, Hans Albert Einstein, was born in Berne, Switzerland. Their second son, Eduard, was born in Munich on July 28, 1910.
Einstein and Marić divorced on February 14, 1919, having lived apart for five years. On June 2 of that year, Einstein married Elsa Löwenthal, who had nursed him through an illness. Elsa was Albert's first cousin maternally and his second cousin paternally. Together the Einsteins raised Margot and Ilse, Elsa's daughters from her first marriage.[26] Their union produced no children.

Annus Mirabilis
In 1905, while he was working in the patent office, Einstein had four papers published in the Annalen der Physik, the leading German physics journal. These are the papers that history has come to call the Annus Mirabilis Papers:





Albert Einstein, 1905

His paper on the particulate nature of light put forward the idea that certain experimental results, notably the photoelectric effect, could be simply understood from the postulate that light interacts with matter as discrete "packets" (quanta) of energy, an idea that had been introduced by Max Planck in 1900 as a purely mathematical manipulation, and which seemed to contradict contemporary wave theories of light.(Einstein 1905a) This was the only work of Einstein's that he himself called "revolutionary."
His paper on Brownian motion explained the random movement of very small objects as direct evidence of molecular action, thus supporting the atomic theory. (Einstein 1905c)
His paper on the electrodynamics of moving bodies introduced the radical theory of special relativity, which showed that the observed independence of the speed of light on the observer's state of motion required fundamental changes to the notion of simultaneity. Consequences of this include the time-space frame of a moving body slowing down and contracting (in the direction of motion) relative to the frame of the observer. This paper also argued that the idea of a luminiferous aether—one of the leading theoretical entities in physics at the time—was superfluous. (Einstein 1905d)
In his paper on mass–energy equivalence (previously considered to be distinct concepts), Einstein deduced from his equations of special relativity what later became the well-known expression: E = mc2, suggesting that tiny amounts of mass could be converted into huge amounts of energy. (Einstein 1905e)

All four papers are today recognized as tremendous achievements—and hence 1905 is known as Einstein's "Wonderful Year". At the time, however, they were not noticed by most physicists as being important, and many of those who did notice them rejected them outright. Some of this work—such as the theory of light quanta—remained controversial for years.[27][28]
At the age of 26, having studied under Alfred Kleiner, Professor of Experimental Physics, Einstein was awarded a PhD by the University of Zurich. His dissertation was entitled A New Determination of Molecular Dimensions. (Einstein 1905b)

Light and general relativity

See also: History of general relativity and Relativity priority dispute


One of the 1919 eclipse photographs taken during Arthur Stanley Eddington's expedition, which confirmed Einstein's predictions of the gravitational bending of light.

In 1906, the patent office promoted Einstein to Technical Examiner Second Class, but he had not given up on academia. In 1908, he became a privatdozent at the University of Bern.[29] In 1910, he wrote a paper on critical opalescence that described the cumulative effect of light scattered by individual molecules in the atmosphere, i.e. why the sky is blue.[30]
During 1909, Einstein published "Über die Entwicklung unserer Anschauungen über das Wesen und die Konstitution der Strahlung" ("The Development of Our Views on the Composition and Essence of Radiation"), on the quantization of light. In this and in an earlier 1909 paper, Einstein showed that Max Planck's energy quanta must have well-defined momenta and act in some respects as independent, point-like particles. This paper introduced the photon concept (although the term itself was introduced by Gilbert N. Lewis in 1926) and inspired the notion of wave–particle duality in quantum mechanics.
In 1911, Einstein became an associate professor at the University of Zurich. However, shortly afterward, he accepted a full professorship at the Charles University of Prague. While in Prague, Einstein published a paper about the effects of gravity on light, specifically the gravitational redshift and the gravitational deflection of light. The paper appealed to astronomers to find ways of detecting the deflection during a solar eclipse.[31] German astronomer Erwin Finlay-Freundlich publicized Einstein's challenge to scientists around the world.[32]

In 1912, Einstein returned to Switzerland to accept a professorship at his alma mater, the ETH. There he met mathematician Marcel Grossmann who introduced him to Riemannian geometry, and at the recommendation of Italian mathematician Tullio Levi-Civita, Einstein began exploring the usefulness of general covariance (essentially the use of tensors) for his gravitational theory. Although for a while Einstein thought that there were problems with that approach, he later returned to it and by late 1915 had published his general theory of relativity in the form that is still used today (Einstein 1915). This theory explains gravitation as distortion of the structure of spacetime by matter, affecting the inertial motion of other matter.
After many relocations, Mileva established a permanent home with the children in Zurich in 1914, just before the start of World War I. Einstein continued on alone to Berlin, where he became a member of the Prussian Academy of Sciences. As part of the arrangements for his new position, he also became a professor at the Humboldt University of Berlin, although with a special clause freeing him from most teaching obligations. From 1914 to 1932 he was also director of the Kaiser Wilhelm Institute for Physics.[33]
During World War I, the speeches and writings of Central Powers scientists were available only to Central Powers academics, for national security reasons. Some of Einstein's work did reach the United Kingdom and the United States through the efforts of the Austrian Paul Ehrenfest and physicists in the Netherlands, especially 1902 Nobel Prize-winner Hendrik Lorentz and Willem de Sitter of the Leiden University. After the war ended, Einstein maintained his relationship with the Leiden University, accepting a contract as an Extraordinary Professor; he travelled to Holland regularly to lecture there between 1920 and 1930.[34]
In 1917, 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 (Einstein 1917b). He also published a paper introducing a new notion, the cosmological constant, into the general theory of relativity in an attempt to model the behavior of the entire universe (Einstein 1917a).
1917 was the year astronomers began taking Einstein up on his 1911 challenge from Prague. The Mount Wilson Observatory in California, U.S., published a solar spectroscopic analysis that showed no gravitational redshift.[35] In 1918, the Lick Observatory, also in California, announced that they too had disproven Einstein's prediction, although their findings were not published.[36]
However, in May 1919, a team led by British astronomer Arthur Stanley Eddington claimed to have confirmed Einstein's prediction of gravitational deflection of starlight by the Sun while photographing a solar eclipse in Sobral, northern Brazil, and Príncipe.[32] On November 7, 1919, leading British newspaper The Times printed a banner headline that read: "Revolution in Science – New Theory of the Universe – Newtonian Ideas Overthrown".[37] In an interview Nobel laureate Max Born praised general relativity as the "greatest feat of human thinking about nature";[38] fellow laureate Paul Dirac was quoted saying it was "probably the greatest scientific discovery ever made".[39]

In their excitement, the world media made Albert Einstein world-famous. Ironically, later examination of the photographs taken on the Eddington expedition showed that the experimental uncertainty was of about the same magnitude as the effect Eddington claimed to have demonstrated, and in 1962 a British expedition concluded that the method used was inherently unreliable.[37] The deflection of light during a solar eclipse has, however, been more accurately measured (and confirmed) by later observations.[40]

There was some resentment toward the newcomer Einstein's fame in the scientific community, notably among German physicists, who later started the Deutsche Physik (German Physics) movement.[41][42]
Nobel Prize


Einstein, 1921. Age 42.

In 1921 Einstein was awarded the Nobel Prize in Physics, "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect". This refers to his 1905 paper on the photoelectric effect: "On a Heuristic Viewpoint Concerning the Production and Transformation of Light", which was well supported by the experimental evidence by that time. The presentation speech began by mentioning "his theory of relativity [which had] been the subject of lively debate in philosophical circles [and] also has astrophysical implications which are being rigorously examined at the present time." (Einstein 1923) As stipulated in their 1919 divorce settlement, Einstein gave the Nobel prize money to his first wife, Mileva Marić.

Einstein traveled to New York City in the United States for the first time on April 2, 1921. When asked where he got his scientific ideas, Einstein explained that he believed scientific work best proceeds from an examination of physical reality and a search for underlying axioms, with consistent explanations that apply in all instances and avoid contradicting each other. He also recommended theories with visualizable results (Einstein 1954).[43]
Unified field theory
Main article: Classical unified field theories


Max Planck presents Einstein with the inaugural Max Planck Medal, Berlin June 28, 1929

Einstein's research after general relativity consisted primarily of a long series of attempts to generalize his theory of gravitation in order to unify and simplify the fundamental laws of physics, particularly gravitation and electromagnetism. In 1950, he described this "unified field theory" in a Scientific American article entitled "On the Generalized Theory of Gravitation" (Einstein 1950).

Although he continued to be lauded for his work in theoretical physics, Einstein became increasingly isolated in his research, and his attempts were ultimately unsuccessful. In his pursuit of a unification of the fundamental forces, he ignored some mainstream developments in physics (and vice versa), most notably the strong and weak nuclear forces, which were not well understood until many years after Einstein's death. Einstein's goal of unifying the laws of physics under a single model survives in the current drive for the grand unification theory.[44]
Collaboration and conflict
Bose–Einstein statistics

In 1924, Einstein received a description of a statistical model from Indian physicist Satyendra Nath Bose which showed that light could be understood as a gas. Bose's statistics applied to some atoms as well as to the proposed light particles, and Einstein submitted his translation of Bose's paper to the Zeitschrift für Physik. Einstein also published his own articles describing the model and its implications, among them the Bose–Einstein condensate phenomenon that should appear at very low temperatures (Einstein 1924). 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.[45] Bose–Einstein statistics are now used to describe the behaviors of any assembly of "bosons". Einstein's sketches for this project may be seen in the Einstein Archive in the library of the Leiden University.[46]
Schrödinger gas model
Einstein suggested to Erwin Schrödinger an application of Max Planck's idea of treating energy levels for a gas as a whole rather than for individual molecules, and Schrödinger applied this in a paper using the Boltzmann distribution to derive the thermodynamic properties of a semiclassical ideal gas. Schrödinger urged Einstein to add his name as co-author, although Einstein declined the invitation.[47]
Einstein refrigerator
In 1926, Einstein and his former student Leó Szilárd, a Hungarian physicist who later worked on the Manhattan Project and is credited with the discovery of the chain reaction, co-invented (and in 1930, patented) the Einstein refrigerator, revolutionary for having no moving parts and using only heat, not ice, as an input.[48][49]
Bohr versus Einstein


Einstein and Niels Bohr. Photo taken by Paul Ehrenfest during their visit to Leiden in December 1925.
In the 1920s, quantum mechanics developed into a more complete theory. Einstein was unhappy with the "Copenhagen interpretation" of quantum theory developed by Niels Bohr and Werner Heisenberg, wherein quantum phenomena are inherently probabilistic, with definite states resulting only upon interaction with classical systems. A public debate between Einstein and Bohr followed, lasting for many years (including during the Solvay Conferences). Einstein formulated thought experiments against the Copenhagen interpretation, which were all rebutted by Bohr. In a 1926 letter to Max Born, Einstein wrote: "I, at any rate, am convinced that He [God] does not throw dice." (Einstein 1969).[50]

Einstein was never satisfied by what he perceived to be quantum theory's intrinsically incomplete description of nature, and in 1935 he further explored the issue in collaboration with Boris Podolsky and Nathan Rosen, noting that the theory seems to require non-local interactions; this is known as the EPR paradox (Einstein 1935). The EPR experiment has since been performed, with results confirming quantum theory's predictions.[51]
Einstein's disagreement with Bohr revolved around the idea of scientific determinism. For this reason the repercussions of the Einstein-Bohr debate have found their way into philosophical discourse as well.
See also: Bohr-Einstein debates
Death

On April 17, 1955, Albert Einstein experienced internal bleeding caused by the rupture of an aortic aneurysm.[87] He took a draft of a speech he was preparing for a television appearance commemorating the State of Israel's seventh anniversary with him to the hospital, but he did not live long enough to complete it.[88] He died in Princeton Hospital early the next morning at the age of 76. Einstein's remains were cremated and his ashes were scattered.[89][90]
Before the cremation, Princeton Hospital pathologist Thomas Stoltz Harvey removed Einstein's brain for preservation, in hope that the neuroscience of the future would be able to discover what made Einstein so intelligent.[91]