Imagination is more important than knowledge.
Albert Einstein (March 14, 1879 – April 18, 1955) was a German-born theoretical physicist widely regarded as one of the greatest and most influential scientists in history. Best known for developing the theory of relativity, he also made significant contributions to quantum mechanics and statistical mechanics. His mass–energy equivalence formula, *E = mc²*, is one of the most famous equations in physics. In 1921, Einstein received the Nobel Prize in Physics for his explanation of the photoelectric effect. Beyond science, he was a vocal advocate for pacifism, civil rights, and socialism, and his iconic image symbolizes genius.
Albert Einstein was born on March 14, 1879, in Ulm, in the Kingdom of Württemberg, German Empire, to secular Ashkenazi Jewish parents Hermann Einstein, a salesman and engineer, and Pauline Koch. The family moved to Munich shortly after his birth, where Hermann and his brother founded a company manufacturing electrical equipment. As a child, Einstein was slow to speak, leading his parents to consult a doctor, but he later recalled speaking fluently by age nine. At age five, he was fascinated by a pocket compass his father showed him, sparking his interest in invisible forces.
He attended a Catholic elementary school in Munich from age five, then the Luitpold Gymnasium for advanced education. Einstein clashed with the rigid, authoritarian style of education, feeling alienated and often rebelling against teachers. In 1894, business failures prompted the family to move to Italy, leaving Einstein in Munich to finish school. Miserable and facing military service, he obtained a doctor's note and rejoined his family in Pavia.
From an early age, Einstein excelled in physics and mathematics, teaching himself algebra and Euclidean geometry by age 12. A family tutor, Max Talmud, introduced him to higher mathematics, philosophy, and popular science books, inspiring his first scientific paper at age 16 on the state of the ether in magnetic fields.
In 1895, at age 16, Einstein attempted the entrance exam for the Swiss Federal Polytechnic (later ETH) in Zurich but failed the general section, though he excelled in physics and math. He completed secondary schooling at the progressive Argovian Cantonal School in Aarau, Switzerland, graduating in 1896. There, he boarded with the Winteler family and fell in love with their daughter, Marie.
Einstein enrolled in the Polytechnic's four-year mathematics and physics teaching diploma program in 1896, where he met lifelong friends like Marcel Grossmann and his future wife, Mileva Marić, a Serbian physics student. He graduated in 1900 but struggled academically in some areas due to skipping classes. In 1905, he earned his PhD from the University of Zurich with a dissertation on molecular dimensions.
After graduation, Einstein faced difficulty securing an academic position and worked temporary jobs before landing a role as a technical assistant at the Swiss Patent Office in Bern in 1902. This stable job allowed him time for research. In 1908, he became a Privatdozent at the University of Bern, followed by professorships at the University of Zurich (1909), Charles-Ferdinand University in Prague (1911), and ETH Zurich (1912).
In 1914, he moved to Berlin as director of the Kaiser Wilhelm Institute for Physics and professor at the University of Berlin, with no teaching obligations. During World War I, he opposed German militarism. In 1933, with the rise of the Nazis, Einstein renounced his German citizenship and emigrated to the United States, joining the Institute for Advanced Study in Princeton, where he remained until retirement in 1945. He became a U.S. citizen in 1940 while retaining Swiss citizenship.
Post-war, Einstein advocated for world government and nuclear disarmament, co-signing the Russell–Einstein Manifesto in 1955.
1905 was Einstein's "annus mirabilis," when he published four revolutionary papers:
In 1915, he completed the **general theory of relativity**, describing gravity as spacetime curvature, confirmed by the 1919 solar eclipse. Other contributions include Bose–Einstein statistics (1924), stimulated emission (1917, basis for lasers), and the EPR paradox (1935) on quantum entanglement. He pursued unified field theory unsuccessfully and critiqued quantum mechanics' probabilistic nature.
Einstein married Mileva Marić in 1903; they had a daughter, Lieserl (fate unknown), and sons Hans Albert (engineer) and Eduard (who suffered from schizophrenia). The marriage ended in divorce in 1919 amid Einstein's affair with his cousin Elsa Löwenthal, whom he married that year; Elsa died in 1936. He had several extramarital relationships.
A passionate violinist, Einstein found solace in music, favoring Mozart and Bach. He was a vegetarian later in life, agnostic, and identified as a "deeply religious nonbeliever." Politically, he supported Zionism but declined Israel's presidency in 1952, advocated civil rights, and opposed McCarthyism.
In his later years, Einstein focused on unified field theory at Princeton, becoming somewhat isolated from mainstream physics. He died on April 18, 1955, in Princeton from an abdominal aortic aneurysm, refusing surgery. His brain was preserved for study, revealing unique features potentially linked to his intelligence.
Einstein's work revolutionized physics, enabling technologies like GPS, lasers, and nuclear energy. He received numerous honors, including the Copley Medal (1925) and Time magazine's Person of the Century (1999). His advocacy for peace and human rights endures, with institutions like the Hebrew University of Jerusalem bearing his influence. Einstein remains a cultural icon of scientific brilliance and humanitarianism.