Today in 1879, Albert Einstein was born. Einstein was the son of an electrical engineer in Ulm, Germany. Though obviously, his contributions to science and technology would far surpass electrical engineering.
Einstein grew up in Germany and Italy, and went on to study physics and math at the Federal Polytechnic Academy in Zurich. He applied for Swiss citizenship and it was granted. He was then awarded a Ph.D. from the University of Zurich. At the time, he was working in a Bern patent office. That year, 1905, would later be called the "annus mirabilis," or "miracle year," in which he published the theoretical papers that would change not only his life but our understanding of physics.
The first paper was titled On a Heuristic Viewpoint Concerning the Production and Transformation of Light. He postulated, correctly, that light is composed of photons which behave individually like particles and collectively like waves. Einstein reached this conclusion after studying the photoelectric effect, in which certain kinds of solid matter produce electrically charged particles when hit by light. For this paper, Einstein was awarded the Nobel Prize in Physics in 1921.
In the second paper he published, he proposed a method for counting the atoms in a given amount of space. And in the third, he attempted to explain, mathematically, the Brownian motion, in which particles suspended in fluid move erratically. Together, the papers constituted proof of the reality of atoms, still a controversial hypothesis at the time.
The fourth paper was Einstein's first expression of the special theory of relativity, which postulates that time and space are properties relative to the observer's motion. The fifth paper of the miracle year investigated the mathematics involved in the special theory. In this paper, Einstein proposed that mass and energy were equivalent and could be accounted for with the famous equation E=mc2.
The intellectual hoi polloi of Europe immediately recognized Einstein as one of their own. He was given professorships across Europe and then published The Foundation of the General Theory of Relativity in 1916. It hypothesized that gravity isn't a force but a curved field in space-time that's created by the presence of mass. By this theory, a large gravitational object like a star would give the impression of warping space and time around it, which could be observed in light distortions. This effect was observed by astronomers in 1919, while studying a solar eclipse. The general theory was later further corroborated by observations in the shift of Mercury's orbit and the likely existence of black holes.
Einstein continued publishing papers about quantum theory and began work on a "unified field theory," which he hoped would bridge the gap between quantum mechanics and relativity theory, as a single explanatory theory to describe all physical phenomena. After the general theory was proven, Einstein became a global celebrity. He used his fame to promote political advocacies. Einstein, himself Jewish, was pro-Zionism. An unpopular opinion in prewar Germany.
After Hitler rose to power, Einstein renounced his German citizenship and eventually immigrated to America. He held a post at the Institute for Advanced Study in Princeton, New Jersey, where he would stay until he died. He was made an American citizen in 1940.
Einstein was a pacifist, but in 1939 added his name to a letter addressed to FDR from a collection of scientists who were worried that the United States was lagging in atomic weapon research and development. Einstein did not, however, play a role in the Manhattan Project and condemned America's use of nuclear weapons against Japan. After the hostilities were over, Einstein advocated for the establishment of a global government to control nuclear technology and stave off future world wars.
Einstein published his unified field theory in 1950 but it was generally considered to be a failed attempt. A working unified field theory has yet to be presented. Einstein died in 1955.