Niels Bohr, Danish Physicist
Niels Henrik David Bohr (October 7, 1885 - November 18, 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. Bohr published his model of atomic structure in 1913 wherein he introduced the theory of electrons traveling in orbits around the atom's nucleus, the chemical properties of each element being largely determined by the number of electrons in the outer orbits of its atoms. He also introduced the idea that an electron could drop from a higher-energy orbit to a lower one, in the process emitting a photon (light quantum) of discrete energy. This became a basis for quantum theory. Bohr mentored and collaborated with many of the top physicists of the century at his institute in Copenhagen. He was part of the British team of physicists working on the Manhattan Project where he was known by the name of Nicholas Baker for security reasons. His role on the project was as consultant. Bohr believed that atomic secrets should be shared by the international scientific community. Oppenheimer suggested that Bohr visit President Roosevelt to convince him that the Manhattan Project should be shared with the Soviets in the hope of speeding up its results. Roosevelt suggested that Bohr return to the United Kingdom to try to win British approval. Winston Churchill disagreed. Following the war Bohr returned to Copenhagen. He continued to advocate the peaceful use of nuclear energy. He died in Copenhagen in 1962 of heart failure. His son, Aage Bohr, grew up to be an important physicist who in 1975 also received the Nobel Prize. Bohr has been described as one of the most influential scientists of the 20th century
