Niels Bohr - Biography, Inventions and Achievements

Niels Henrik David Bohr 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. He developed the model of the atom with the atomic nucleus at the center and electrons in orbit around it, which he compared to the planets orbiting the Sun. He worked on the idea in quantum mechanics that electrons move from one energy level to another in discrete steps, not continuously.

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. Bohr married Margrethe Nørlund in 1912, and one of their sons, Aage Bohr, was also a physicist and in 1975 also received the Nobel Prize. Niels Bohr was born in Copenhagen, Denmark, on 7 October 1885, the second of three children of Christian Bohr, a professor of physiology at the University of Copenhagen, and Ellen Adler Bohr, who came from a wealthy Danish Jewish family prominent in banking and parliamentary circles.

He had a sister, Jenny, who was two years older than him, and a brother Harald, who was two years younger. Jenney became a teacher, while Harald because a mathematician and Olympic footballer who played on the Danish national team at the 1908 Summer Olympics in London. Niels was a passionate footballer as well, and the two brothers played a number of matches for the Copenhagen-based Akademisk Boldklub, with Niels playing goalkeeper.

Bohr was educated at Gammelholm Latin School, which he started when he was seven. In 1903, Bohr enrolled as an undergraduate at Copenhagen University. His major was physics, which he studied under Professor Christian Christiansen, the university's only professor of physics at that time. He also studied astronomy and mathematics under Professor Thorvald Thiele, and philosophy under Professor Harald Høffding, a friend of his father's.

Inventions, Achievements and Brief Introduction of Niels Bohr

• Niels Bohr was a Danish physicist, who was awarded the Nobel Prize in Physics 1922 "for his services in the investigation of the structure of atoms and of the radiation emanating from them".
• Earlier in 1910, Niels Bohr had met Margrethe Norlund, sister of the mathematician Niels Erik Norlund. They tied the knot in Copenhagen in 1912.
• Of their six sons, the oldest died in a boating accident and another died from childhood meningitis.
• This model introduced by Bohr in 1913, was a radical departure from earlier descriptions of the atom and showed the atom as one with a small nucleus surrounded by electrons that travel in circular orbits in a structure similar to the solar system, with electrostatic forces providing attraction, not gravity.
•  Niels played soccer and was on the college team (He was not as good as his brother who played Denmark and won silver in the 1908 Olympics.)
• Niels and Margethe's son, Aage, followed in his fathers footsteps in physics. Aage also won the Nobel Peace Prize (like Niels) in 1975.
• Niels Bohr's Institute of Theoretical Physics was sponsored by Carlsberg Brewery (Famous Danish Brewery)
• Not only did Bohr make major contributions to theoretical physics, he was also a wonderful administrator.
• During the debate about Quantum Theory with Albert Einstein, Einstein said "God does not play dice." Bohr replied by saying "Einstein, stop telling God what to do!"
• In 1922, Bohr was awarded the Nobel Prize in Physics. In 1927, Heisenberg developed his uncertainty principle, while working on the mathematical foundations of quantum mechanics.
• During World War II Bohr, fearing arrest by the Germans, escaped to Britain from where he went to the US to work on the Manhattan Project at the Los Alamos laboratory in New Mexico. The Manhattan Project lead to the development of the first atom bomb.
• Following the war Bohr returned to Copenhagen. He continued to preach the peaceful use of nuclear energy.
• When he was awarded the Order of the Elephant by the Danish government, he designed his own coat of arms which featured a taijitu (symbol of yin and yang).
• Niels Bohr died in Copenhagen on November 18, 1962. His son, Aage Bohr, was also awarded the Nobel Prize in Physics in 1975.
• In 1913, Bohr’s model of atomic structure was published which became the basis of the famous quantum theory. In 1916, Niels Bohr became a Professor at the University of Copenhagen and later founded the Institute of Theoretical Physics in 1921. Bohr’s institute became headquarter for theoretical physicists and most of the best known physicists contributed there.
• Due to security reasons Niels Bohr assumed the name of Nicholas baker for the top-secret Manhattan Project in New Mexico, America. Soon after the World War II, Bohr started advocating the peaceful use of nuclear energy in Copenhagen.
• ‘The Bohr model of the atom’, ‘The shell model of the atom’, ‘The correspondence principle’, ‘The liquid drop model of the atomic nucleus’, the identification of uranium isotope and ‘The principle of complementarity’ are some of his major contributions to the field of physics and chemistry.
• Bohr died on 18th November 1962, at the age of 77 because of a heart failure. He is buried in the Assistens Kierkegaard in Copenhagen, Denmark. In 1965, in honor of Bohr the Institute of Physics at the University of Copenhagen changed its name to the Niels Bohr Institute. Chemical Element ‘Bohrium’ and ‘Asteroid 3948 Bohr’ being named after him are few of his legacies.

Superb Quotes by Niels Bohr

• If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet.
• If anybody says he can think about quantum physics without getting giddy, that only shows he has not understood the first thing about them.
• It is wrong to think that the task of physics is to find out how Nature is. Physics concerns what we say about Nature.
• Physics is to be regarded not so much as the study of something a priori given, but rather as the development of methods of ordering and surveying human experience. In this respect our task must be to account for such experience in a manner independent of individual subjective judgement and therefore objective in the sense that it can be unambiguously communicated in ordinary human language.
• There is no quantum world. There is only an abstract physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature...
• Physics is to be regarded not so much as the study of something a priori given, but rather as the development of methods of ordering and surveying human experience. In this respect our task must be to account for such experience in a manner independent of individual subjective judgement and therefore objective in the sense that it can be unambiguously communicated in ordinary human language...
• Two sorts of truth: profound truths 
recognized by the fact that the opposite is also a profound truth,
 in contrast to trivialities where opposites are obviously absurd.
• Every sentence I utter must be understood not as an affirmation, but as a question.