Albert Einstein (1879-1955) is celebrated as the twentieth century's greatest theoretical physicist, but most of his creative powers were devoted to constructing theories outside of atomic theory. He was born in Ulm, Germany, on March 14, 1879. His father was an unsuccessful businessman in the electrical equipment business. He married Mileva Maric in 1902, and they had two sons. After a divorce in 1919, Einstein married his cousin, Elsa Lowenthal. At an early age, his family moved to Munich. Einstein attended a Munich Gymnasium, and his early academic successes turned bitter when he rebelled against rote learning in early adolescence. His rebelliousness caused him to be expelled from the Gymnasium. After failing the entrance examination to the Zurich Polytechnical School, he finished his secondary education at Aarau in Switzerland. Einstein gained admittance to the Zurich Polytechnical School, but he was an unexceptional student. His professors generally ignored him, but he did graduate. Unable to find an academic post, he survived as a private tutor and substitute teacher until 1902, when he started work as a technical expert, third class, in the Swiss Patent Office in Bern. Einstein's rebellion against things German culminated in his request for a revocation of German citizenship, which was granted by the German government in 1896. He obtained Swiss citizenship in 1901.
Einstein gained world fame for a series of papers published in 1905 in the physics journal Annalen der Physik in which he outlined his ideas on a variety of problems in physics. The first article was “On the Motion of Small Particles Suspended in a Stationary Liquid According to the Molecular Kinetic Theory of Induction, ” in which Einstein produced a formula for the average displacement of particles in suspension. His formula was later confirmed in 1908 and was the first direct evidence for the existence of atoms