German physicist who, with US physicist James Franck, demonstrated that mercury atoms, when bombarded with electrons, absorb energy in discrete units (or quanta). Following the absorption of energy, the atoms return to their original state by emitting a photon of light. This was the first experimental proof that the quantum theory of atoms was correct and demonstrated the reality of atomic energy levels. He shared the Nobel Prize for Physics in 1925, with Franck, for the discovery of the laws governing the impact of an electron upon an atom.
Gustav Hertz was born in Hamburg, Germany, and obtained his doctorate in Berlin in 1911. He became an assistant in the Berlin physics institute and began his collaboration with Franck. He was professor of experimental physics at the University of Halle 1925–1927. From 1928 to 1935 he worked at the Berlin Techniche Hochschule. Because of his Jewish descent, Hertz was forced to resign in 1935. However, he remained in Germany during World War II, working as director of the Siemens Research laboratory, Berlin. After the war, he was captured by the Russians and taken to the USSR to continue his work in atomic physics. In 1955 he re-emerged as director of the Physics Institute in Leipzig, East Germany. He is the nephew of Heinrich Hertz, the discoverer of radio waves.
1. A theory in physics based on the principle that matter and energy have the properties of both particles and waves, created to explain the radiation of energy from a blackbody, the photoelectric effect, and the Bohr theory, and now used to account for a wide range of physical phenomena, including the existence of discrete packets of energy and matter, the uncertainty principle, and the exclusion principle.
2,In physics, the theory that energy does not have a continuous range of values, but is, instead, absorbed or radiated discontinuously, in multiples of definite, indivisible units called quanta. Just as earlier theory showed how light, generally seen as a wave motion, could also in some ways be seen as composed of discrete particles (photons), quantum theory shows how atomic particles such as electrons may also be seen as having wavelike properties. Quantum theory is the basis of particle physics, modern theoretical chemistry, and the solid-state physics that describes the behaviour of the silicon chips used in computers.
The theory began with the work of Max Planck in 1900 on radiated energy, and was extended by Albert Einstein to electromagnetic radiation generally, including light. Danish physicist Niels Bohr used it to explain the spectrum of light emitted by excited hydrogen atoms. Later work by Erwin Schrödinger, Werner Heisenberg, Paul Dirac, and others elaborated the theory to what is called quantum mechanics (or wave mechanics).
Gustav Ludwig Hertz was born in Hamburg on July 22nd, 1887, the son of a lawyer, Dr. Gustav Hertz, and his wife Auguste, née Arning. He attended the Johanneum School in Hamburg before commencing his university education at Göttingen in 1906; he subsequently studied at the Universities of Munich and Berlin, graduating in 1911. He was appointed Research Assistant at the Physics Institute of Berlin University in 1913 but, with the onset of World War I, he was mobilized in 1914 and severely wounded in action in 1915. Hertz returned to Berlin as Privatdozent in 1917. From 1920 to 1925 he worked in the physics laboratory of the Philips Incandescent Lamp Factory at Eindhoven.In 1925, he was elected Resident Professor and Director of the Physics Institute of the University of Halle, and in 1928 he returned to Berlin as Director of the Physics Institute in the Charlottenburg Technological University. Hertz resigned from this post for political reasons in 1935 to return to industry as director of a research laboratory of the Siemens Company. From 1945 tot 1954 he worked as the head of a research laboratory in the Soviet Union, when he was appointed Professor and Director of the Physics Institute at the Karl Marx University in Leipzig. He was made emeritus in 1961, and since then he has lived in retirement, first in Leipzig and later in Berlin. Hertz's early researches, for his thesis, involved studies on the infrared absorption of carbon dioxide in relation to pressure and partial pressure. Together with J. Franck he began his studies on electron impact in 1913 and before his mobilization, he spent much patient work on the study and measurement of ionization potentials in various gases. He later demonstrated the quantitative relations between the series of spectral lines and the energy losses of electrons in collision with atoms corresponding to the stationary energy states of the atoms. His results were in perfect agreement with Bohr's theory of atomic structure, which included the application of Planck's quantum theory.