Albert Einstein

Albert Einstein (14 March 1879–18 April 1955) was born in Ulm, in the Kingdom of Württemberg, to Hermann Einstein, an entrepreneur in the electrical industry, and Pauline Koch; the family was of German-Jewish origin. Soon after his birth they settled in Munich, where Hermann Einstein and his brother Jakob operated an electrotechnical concern. Einstein attended the Luitpold Gymnasium but left Germany after the family business failed and his parents moved to Italy. Having renounced his Württemberg citizenship in 1896, he completed his secondary education at the cantonal school in Aarau and entered the Swiss Federal Polytechnic in Zurich, now the ETH, to study mathematics and physics. He received his teaching diploma in 1900 and became a Swiss citizen in 1901. Unable immediately to secure an academic appointment, he obtained employment in 1902 as a technical expert at the Swiss Patent Office in Bern, where the examination of electromechanical inventions afforded him financial stability and left sufficient intellectual independence for theoretical research. His Bern circle included Michele Besso, Maurice Solovine, and Conrad Habicht, with whom he formed the informal discussion group known as the Olympia Academy.

In 1903 Einstein married his former Polytechnic classmate Mileva Marić. Their sons, Hans Albert and Eduard, were born in 1904 and 1910 respectively; a daughter born before the marriage disappears from the surviving record. Although Einstein discussed scientific questions with Marić, the extant documentary evidence has not established her coauthorship of his published theories. Their increasingly difficult marriage effectively ended when Einstein moved to Berlin in 1914; they divorced in 1919. In the same year he married his cousin Elsa Löwenthal, née Einstein, with whose daughters Ilse and Margot he maintained a family household. Elsa died in Princeton in 1936.

Einstein’s scientific emergence culminated in 1905, his annus mirabilis. While still employed by the Patent Office, he published four celebrated papers in the Annalen der Physik, besides completing a doctoral dissertation for the University of Zurich on the determination of molecular dimensions. His light-quantum paper proposed that radiation could behave as localized quanta of energy and furnished an explanation of the photoelectric effect. His study of Brownian motion connected observable particle fluctuations with molecular-kinetic theory and provided a quantitative means of testing the atomic constitution of matter. In his paper on the electrodynamics of moving bodies he formulated special relativity by reconciling the principle of relativity with the invariance of the velocity of light, thereby transforming the concepts of simultaneity, space, and time. A short sequel established the inertia of energy, subsequently expressed in the familiar relation E = mc². These works did not arise in isolation from contemporary physics—Einstein engaged critically with the problems inherited from Maxwell, Lorentz, Boltzmann, Planck, and others—but their conceptual synthesis was distinctively his own.

Recognition brought Einstein into academic life. He qualified as a Privatdozent at Bern in 1908, became extraordinary professor at the University of Zurich in 1909, professor of theoretical physics at the German University in Prague in 1911, and professor at the Zurich Polytechnic in 1912. His attention had meanwhile shifted towards a relativistic theory of gravitation. Beginning from the equivalence of uniform acceleration and a homogeneous gravitational field, he sought a theory applicable beyond inertial frames. At Zurich, his friend Marcel Grossmann assisted him in mastering the tensor calculus and differential geometry required for this programme. In 1914 Einstein accepted election to the Prussian Academy of Sciences and an appointment in Berlin that relieved him of regular teaching. After a difficult sequence of preliminary formulations, he arrived in November 1915 at the generally covariant field equations of general relativity. The theory represented gravitation not as a force acting within a fixed space and time but through the dynamical geometry of spacetime; it accounted for the anomalous perihelion advance of Mercury and predicted the gravitational deflection of light.

The eclipse observations organized under British auspices in 1919, associated above all with Arthur Eddington and Frank Dyson, were interpreted as confirming the predicted bending of starlight and abruptly made Einstein an international public figure. His fame encouraged an extensive print culture of exposition, translation, controversy, and caricature. Einstein himself had already prepared a non-technical account, Über die spezielle und die allgemeine Relativitätstheorie (Gemeinverständlich), issued by Vieweg at Braunschweig in 1917 and repeatedly revised and reprinted. His Stafford Little Lectures at Princeton appeared in 1922 as The Meaning of Relativity. The reception of relativity was inseparable from the political and cultural tensions of post-war Europe: legitimate scientific debate was accompanied in Germany by organized opposition in which antisemitism, nationalism, and hostility to modern theoretical physics were conspicuous.

Relativity constituted only one part of Einstein’s scientific work. His studies of quantum phenomena included an early quantum theory of specific heats and, in 1916–17, a treatment of radiation employing coefficients for absorption, spontaneous emission, and stimulated emission. In 1917 he applied general relativity to cosmology, introducing the cosmological term in constructing a static model of the universe. In 1924 he developed Satyendra Nath Bose’s statistical treatment of photons into the quantum statistics of material particles now called Bose–Einstein statistics, with the associated prediction of condensation at very low temperatures. Einstein nevertheless rejected the claim that the probabilistic formalism of quantum mechanics furnished a complete account of physical reality. His long dialogue with Niels Bohr concerned not the empirical success of quantum theory but its interpretation and completeness. The 1935 paper written with Boris Podolsky and Nathan Rosen sharpened this dispute by analysing correlations between spatially separated systems, thereby helping to define problems that later became central to the study of quantum entanglement.

Einstein received the Nobel Prize in Physics for 1921, formally awarded in 1922, for his services to theoretical physics and particularly for his discovery of the law of the photoelectric effect. The wording reflected both the established importance of his quantum work and the Nobel Committee’s caution concerning relativity. During the 1920s he travelled widely as scientist, lecturer, and public intellectual. He supported the Weimar Republic, international intellectual cooperation, civil liberties, and reconciliation between former wartime enemies. Although remote from religious observance and wary of nationalism, he increasingly identified publicly with Jewish communal life in response to antisemitism. He assisted the development of the Hebrew University of Jerusalem, while advocating a form of cultural Zionism that remained critical of aggressive nationalism and attentive to Jewish-Arab coexistence.

Einstein’s opposition to German militarism had been evident during the First World War, when he was among the few German intellectuals to support an anti-war counter-manifesto. His pacifism became less absolute after the rise of National Socialism. Abroad when Hitler became chancellor in 1933, Einstein did not return to Germany; he resigned from the Prussian Academy, renounced German citizenship, and settled permanently in the United States. He joined the newly established Institute for Advanced Study at Princeton, serving on its faculty from 1933 until his death. He also used his international standing to assist scholars and other refugees displaced by Nazi persecution. In 1940 he became an American citizen while retaining his Swiss citizenship.

In August 1939 Einstein signed the letter to President Franklin D. Roosevelt, prepared at the initiative of Leo Szilard and other émigré physicists, warning that nuclear fission might permit the construction of exceptionally powerful weapons and that Germany might pursue such work. His authority gave the warning political weight, but he did not participate in the Manhattan Project. After the war he campaigned for international control of atomic energy, nuclear disarmament, supranational government, and the protection of civil liberties, while also speaking against racial discrimination in the United States. In 1952 he declined an invitation to become the second president of Israel, explaining that he lacked the experience and aptitude required for political office.

Einstein’s later scientific work was dominated by attempts to construct a unified field theory incorporating gravitation and electromagnetism within a single geometrical framework. These investigations did not yield an empirically successful theory and increasingly separated him from the principal developments of particle and quantum physics; they nevertheless expressed his enduring commitment to intelligible, unified, and observer-independent laws of nature. He died in Princeton on 18 April 1955. His scholarly estate, comprising scientific manuscripts, notebooks, correspondence, drafts, political statements, and personal papers, passed ultimately to the Albert Einstein Archives at the Hebrew University of Jerusalem. Its systematic publication in The Collected Papers of Albert Einstein, prepared by the Einstein Papers Project and issued by Princeton University Press, has profoundly altered the documentary basis for studying his science, intellectual networks, family life, political commitments, and international reception. The resulting record reveals a figure whose historical significance rests not only upon relativity, but also upon foundational contributions to statistical physics, quantum theory, cosmology, and the modern public conception of scientific authority.