Heisenberg, Werner, << HY zuhn `burg,` VEHR nuhr >> (1901-1976), a German physicist, made important contributions to the study of the atom. Heisenberg’s work dealt with subatomic particles, the smaller pieces that make up atoms. He developed the uncertainty principle, which states that a subatomic particle’s position and momentum cannot be accurately determined at the same time. Heisenberg presented the uncertainty principle in 1927. He received the 1932 Nobel Prize in physics for founding one version of the field of physics known as quantum mechanics (see Quantum mechanics).
Heisenberg formed his theories about atomic structure by studying light given off by atoms. In 1913, the Danish physicist Niels Bohr had suggested that the electrons in an atom can travel around the nucleus only in a certain set of orbits. Bohr had also shown that changes in the arrangement of these electrons can cause an atom to radiate light. Heisenberg studied the spectra (ranges of frequencies of light) given off by atoms. These studies, conducted in the early 1920’s, led him to develop matrix mechanics, a form of quantum mechanics that provides a mathematical description of electron orbits.
During the 1930’s, Heisenberg developed a model of atomic nuclei in which they are made up of neutrons and protons. This model helped convince many scientists that nuclei did not consist of protons and electrons.
Heisenberg remained in Germany while the Nazi Party ruled the country from 1933 to 1945. During World War II (1939-1945), he headed Germany’s efforts to develop nuclear energy for use in reactors and possibly atomic bombs. Scholars have debated Heisenberg’s role in the program’s failure. Some experts fault Heisenberg’s leadership and research. Other scholars suggest he intentionally hindered the program. Most historians agree that the effort could not have succeeded for a variety of reasons, including limitations on time, funding, and resources related to the war.
Heisenberg was born on Dec. 5, 1901, in Wurzburg, Germany. He studied at the University of Munich. He died on Feb. 1, 1976.
