Albert Einstein (German: IPA2: ˈalbɐt ˈaɪ̯nʃtaɪ̯n (Audio file); English: IPAEng: ˈælbɝt ˈaɪnstaɪn) (14 March 1879 – 18 April 1955) was a German-born theoretical physicist. He is best known for his theory of relativity and specifically mass–energy equivalence, E = mc ². Einstein received the 1921 Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect."

Einstein's many contributions to physics include his special theory of relativity, which reconciled mechanics with electromagnetism, and his general theory of relativity, which was intended to extend the principle of relativity to non-uniform motion and to provide a new theory of gravitation. His other contributions include relativistic cosmology, capillary action, critical opalescence, classical problems of statistical mechanics and their application to quantum theory, an explanation of the Brownian movement of molecules, atomic transition probabilities, the quantum theory of a monatomic gas, thermal properties of light with low radiation density (which laid the foundation for the photon theory), a theory of radiation including stimulated emission, the conception of a unified field theory, and the geometrization of physics.

Einstein published over 300 scientific works and over 150 non-scientific works. Einstein is revered by the physics community, and in 1999 Time magazine named him the "Person of the Century". In wider culture the name "Einstein" has become synonymous with genius.

Youth and schooling

Albert Einstein was born into a Jewish family in Ulm, Württemberg, Germany on 14 March 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.

In 1889, family friend Max Talmud, a medical student,Dudley Herschbach, "Einstein as a Student," Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA, page 3, web: HarvardChem-Einstein-PDF: about Max Talmud visited on Thursdays for six years. 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"). 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.