Niels Bohr was a Danish scientist who made fundamental contributions to physics and was one of the early pioneers of quantum mechanics. He won a Nobel Prize in 1922 for his model of the atom, which put electrons in discrete orbits.
Niels Bohr was a Danish physicist born in Copenhagen on October 7, 1885. Bohr’s most important work was developing a model of the atom. After J. J. Thomson's discovery of the electron in 1897, scientists were aware that the atom was made up of smaller particles. After Ernest Rutherford’s experiment with gold and alpha particles, they knew atoms had a small dense nucleus with electrons orbiting around it. Using classical laws to explain the atomic structure, the electrons would very quickly spiral towards the nucleus: the nucleus is positively charged and the electrons are negatively charged so they attract.
Bohr developed a model in which he proposed that the electrons have discrete energy levels and that electrons move around the nucleus in stable orbits. He also proposed that electrons could move from one energy level to another by emitting and absorbing energy. The energy that was emitted and absorbed was found to be at fixed wavelengths, and the Bohr atomic model had the ability to explain those observations.
Bohr continued to work on the newly emerging field of quantum mechanics. He formulated the principle of complementarity, meaning there are properties which cannot be measured or observed at the same time. An example of this is the wave-particle duality.
Bohr pushed for the Danish government to set up a center of theoretical physics in 1920, where Bohr became the center director for nearly his entire life. Niels Bohr received a Nobel Prize for his work on his model of the atom in 1922.
During World War II, Bohr was extremely concerned for the welfare of his Jewish peers and offered a place for them in Denmark. He worked with a number of other prominent scientists on the Manhattan Project. This project later resulted in the first nuclear bomb being dropped on Japan.
Bohr died in his home in 1962 after he suffered a stroke.
“An expert is a person who has made all the mistakes that can be made in a very narrow field.”
“The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth.”
“Every great and deep difficulty bears in itself its own solution. It forces us to change our thinking in order to find it.”