Albert Einstein

Albert Einstein (1879 to 1955) was a German-born theoretical physicist who developed the theories of special and general relativity and helped lay the foundations of quantum theory. In 1905, while working as a patent clerk, he published papers that changed how scientists think about space, time, light and matter. He received the 1921 Nobel Prize in Physics, and his name has become a common shorthand for scientific genius.

Early life of Albert Einstein

Einstein was born in Ulm, in the German state of Württemberg, on March 14, 1879. His family moved to Munich six weeks later, and he began school at the Luitpold Gymnasium. The family later moved to Italy, and he continued his schooling at Aarau, Switzerland. In 1896 he entered the Swiss Federal Polytechnic School in Zurich to train as a teacher of physics and mathematics.

He graduated in 1901 and gained Swiss citizenship the same year. Unable to find a teaching post, he took a job as a technical assistant at the Swiss Patent Office in Bern. According to the Nobel Foundation, he did much of his most remarkable work there in his spare time, and he earned his doctorate in 1905. He went on to hold university posts in Bern, Zurich and Prague, and in 1914 he became director of the Kaiser Wilhelm Physical Institute and a professor at the University of Berlin.

Major contributions of Albert Einstein

Special relativity

Einstein saw that Newtonian mechanics did not fit well with the laws of electromagnetism. His special theory of relativity, published in 1905, grew out of an attempt to reconcile the two. It rests on the idea that the laws of physics are the same for all observers moving at constant speed, and that the speed of light is the same for all of them. A major consequence is that time and distance are not absolute, but depend on the observer’s motion. Another, which he reported that year, is that mass and energy are equivalent, summed up in the equation E = mc squared.

This changed the framework that Isaac Newton had set out in the Principia. At everyday speeds, Newton’s laws of motion still work almost perfectly. Relativity matters when speeds approach that of light.

Brownian motion and the quantum of light

Also in 1905, Einstein developed a kinetic theory of Brownian movement, the jittery motion of tiny particles suspended in a liquid. The Nobel committee noted that his theory explained the main properties of such suspensions and helped build the field of colloid chemistry. For physicists it was strong evidence that atoms and molecules are real.

That same year he studied the thermal properties of light and proposed that light behaves in some respects as if it consists of individual packets of energy, later called photons. This laid the foundation of the photon theory of light. In 1921 the Nobel Prize recognized his law of the photoelectric effect, in which light shining on a metal knocks out electrons. Einstein explained that a light quantum can free an electron only if its frequency is high enough, no matter how intense the light is. The American physicist Robert Millikan tested the law rigorously, and it held.

General relativity

Einstein then asked what the correct form of relativity would say about gravity. He worked on the problem for about a decade, and in 1916 he published his paper on the general theory of relativity. Instead of treating gravity as a force acting across empty space, the theory describes it as the curvature of spacetime caused by mass and energy. It predicted that light would bend as it passes a massive body. Observations of a solar eclipse in 1919 matched the prediction, and the result made Einstein world famous.

The theory also underlies relativistic cosmology, the study of the universe as a whole. Satellite navigation such as the Global Positioning System must account for relativistic effects on its clocks to stay accurate.

Later life

Einstein became a German citizen in 1914 and remained in Berlin until 1933, when he renounced his citizenship for political reasons and emigrated to the United States. He took a position at the Institute for Advanced Study in Princeton, New Jersey. He became a US citizen in 1940 and retired in 1945.

From the 1920s he worked on unified field theories that would combine gravity and electromagnetism. He never completed one. He also remained a critic of the probabilistic interpretation of quantum theory, a stance captured in his remark that God does not play dice, to which the Danish physicist Niels Bohr is said to have replied that Einstein should stop telling God what to do.

After World War II, Einstein was a leading figure in the world government movement. He helped establish the Hebrew University of Jerusalem, and he declined an offer to become president of Israel. He died at Princeton on April 18, 1955.

Legacy of Albert Einstein

Relativity and quantum theory, two fields Einstein did much to start, are the pillars of modern physics. His work on mass and energy is central to the physics of the nuclear power that followed decades later. His theory of gravity guides how astronomers model black holes, gravitational waves and the expansion of the universe. Many of the effects he described have been confirmed again and again with ever more precise instruments.

Einstein received honorary degrees from many universities and, as the Nobel Foundation notes, belonged to the leading scientific academies of the world. He also received the Copley Medal of the Royal Society in 1925. Outside physics he became an advocate for peace and civil rights, and a global symbol of curiosity.

FAQs

What is Albert Einstein best known for? He is best known for the theories of special and general relativity and for the equation E = mc squared, which expresses the equivalence of mass and energy.

Did Einstein win the Nobel Prize for relativity? No. The 1921 prize, announced in 1922, honored his services to theoretical physics and especially his law of the photoelectric effect.

Where did Einstein work? He worked in Bern, Zurich, Prague and Berlin, and from 1933 at the Institute for Advanced Study in Princeton.

When did Albert Einstein die? He died on April 18, 1955, at Princeton, New Jersey.

Editorially reviewed by Specialty Digest Editorial TeamLast reviewed November 4, 2026Researched and drafted with AI assistanceReport an issue