Albert Einstein

Albert Einstein was born in Ulm in 1879 into a Jewish middle-class family in Germany. His father, Hermann, and uncle Jakob ran a business making electrical equipment; his mother, Pauline, came from a prosperous merchant family. He grew up mainly in Munich, attending a Catholic primary school and later a secondary school. As a child he showed an interest in mathematics and questions about physical nature.

After a period in Switzerland, Einstein studied at the Eidgenössische Polytechnische Schule in Zurich, where he gained a teaching qualification in mathematics and physics in 1900. An academic post did not initially materialise; in 1902 he found work at the Swiss patent office in Bern. The job gave him financial security and time to study physics problems independently, outside the daily routine of a university research group.

In 1905 Einstein published four influential papers on subjects including the photoelectric effect, Brownian motion, special relativity and the relationship between mass and energy. His explanation of the photoelectric effect used light quanta and contributed to the development of quantum physics. Relativity revised ideas about simultaneity, space and time; it was based on mathematical analysis and existing problems in physics.

Einstein then worked on a theory describing gravity as the curvature of spacetime. He completed the general theory of relativity in 1915; observations during the 1919 solar eclipse became widely known as support for its prediction that gravity bends light. He continued to contribute to statistical physics, quantum theory and cosmology, although he was critical of some interpretations of quantum mechanics.

After the Nazis came to power in 1933, Einstein settled in the United States and worked at the Institute for Advanced Study in Princeton. In 1939 he signed a letter to President Roosevelt drawing attention to possible German research into nuclear weapons; he did not work on the Manhattan Project. After the war he advocated international control of nuclear weapons, civil rights and cooperation between states.

Einstein lived through rapid changes in physics, technology and communication. Electromagnetism, railways and telegraphy raised new questions about light, motion and the measurement of time. Quantum physics and relativity emerged from debates within European universities and scientific societies. The First World War, the crisis of the Weimar Republic and Nazism then altered the institutions and personal circumstances in which scientists could work.

As a Jewish intellectual, Einstein faced antisemitism that intensified in Germany and became state policy under the Nazi regime. He already had an international reputation before 1933 and was able to emigrate to the United States, but many other scientists lost their positions or fled under more difficult circumstances. Nuclear weapons and the Cold War also drew physicists into public debates about responsibility and policy.

Relativity and quantum theory transformed theoretical physics and later became relevant to applications including nuclear physics, cosmology and satellite navigation. Einstein’s public recognition grew sharply after observations in 1919 attracted widespread attention. His fame rested not on his research alone: experimental measurements, the work of other physicists and later technological developments were essential to testing and applying the theories.

Einstein also used his public standing to support pacifism, refugees, civil rights and international cooperation. His signature on the 1939 letter to Roosevelt is sometimes simplified as direct participation in the development of the atomic bomb; he did not work on the Manhattan Project and later criticised nuclear armament. His political statements were discussed amid war, state security and ideological polarisation.

Einstein died in Princeton in 1955, where he had lived and worked since 1933. He was cremated and his ashes were scattered at an undisclosed location; his brain was removed after his death for study without prior agreement with him. His scientific legacy includes manuscripts, correspondence and ideas that physicists have continued to test, refine and apply.

Einstein remains one of the best-known physicists, although his public image can obscure the collective nature of scientific progress. His theories are foundations of modern physics and are tested under many conditions. He is also studied as a public intellectual who spoke about civil rights and nuclear risks; historical scholarship distinguishes his specific positions from later representations of him.