Albert Einstein is widely considered to be the most famous and accomplished scientist of the 20th century. He was awarded the 1921 Nobel Prize for Physics for his work on the photoelectric effect, and achieved world fame for his general theory of relativity, which he released in 1915. In 1999, he was named Person of the Century by TIME magazine.
Einstein is known best for his general theory of relativity, an improved model of reality which succeeded the less-precise Newtonian model. He described fundamental connections between space and time, matter and energy. He considered space and time to be manifestations of the same underlying thing, as well as matter and energy. Because his theories were so complicated and controversial, it sometimes took a decade or more until they were accepted by the scientific community. In addition, due to his Jewish descent, his time spent in Germany during the rise of German nationalism made him the target of campaigns to discredit his theories.
The future physicist was born in 1879 in Ulm, now a part of Germany. He attended school in Munich until 1895, when, at the age of 16, he dropped out of secondary school a year early. Albert Einstein applied to the Swiss Federal Institute of Technology in Zurich, but failed the liberal arts portion of the entrance exam. This led to him going back to secondary school in Aarau, Switzerland, which he graduated in 1896. After his completion of secondary school, he applied again to the Swiss Federal Institute of Technology, being accepted. He received his diploma in 1900, and went to work for a Swiss patent office in 1902.
Albert Einstein continued to pursue physics on the side throughout his work at the patent office, receiving his doctorate in 1905. That same year, he published 4 papers that later served as the foundation for much of modern physics. The topics he addressed were Brownian motion, the photoelectric effect, and special relativity. The theory which prompted the most discussion throughout coming decades was his theory of special relativity, which explained why the speed of light appears constant to any observer, despite their velocity.
From 1906 onward, he became increasingly involved in academia, working at universities in Zurich and Berlin, where in 1914 he became director of the Kaiser Wilhelm Institute for Physics. In 1915 he described his famous general theory of relativity, which was viewed with skepticism until it was confirmed experimentally in 1919.
In 1933, Adolf Hitler came to power, and Albert Einstein was forced to leave Germany for the United States, where he went to work at the Institute for Advanced Study at Princeton; and in 1940, became a U.S. citizen. He stayed at Princeton until his death in 1955, working on a theory of physics which unified gravity with the other forces of nature. He never succeeded. Today, physicists' best bet for realizing Einstein's dream, according to many scientists, lies with the theory of superstrings, still largely hypothetical.