
The 20thcentury answer to Isaac Newton, Albert Einstein (18791955) revolutionized our concepts of space and time and developed the theories used to build models of the universe. He was born in Ulm, Germany, though his family moved to Munich shortly thereafter. He showed little academic promise as a teenager, and didnít begin to make his mark until he moved to Zurich, Switzerland. Working as a patent clerk in Berne in the first years of the new century, he was able to spend his spare time studying physics. Einsteinís great year was 1905, when he produced three papers of tremendous significance. One gave a mathematical description of the random motions of tiny particles. A second described the photoelectric effect, in which electrons are emitted when light falls on certain metals. (Many people are surprised to learn that he won the Nobel Prize for this description and not for his theories of relativity.) The third paper of the year was on special relativity, in which he described the physics of objects moving at constant velocities and discovered the equivalence of mass and energy as related by the equation E=mc^{2}. It took Einstein 10 more years to develop his general theory of relativity, which describes the universe as a whole and forms the basis for our understanding of the structure of the universe. 