Editing Walther Nernst (section)

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Nernst published his book ''The Foundations of the New Heat Theorem''. In 1918, after studying [[photochemistry]], he proposed the atomic chain reaction theory. It stated that when a reaction in which free atoms are formed that can decompose target molecules into more free atoms would result in a chain reaction. His theory is closely related to the natural process of [[Nuclear Fission|nuclear fission]].

In 1920, he and his family briefly fled abroad because he was one of the scientists on the [[Allies of World War I|Allied]] list of war criminals. Later that year he received the [[Nobel Prize in Chemistry]] in recognition of his work on [[thermochemistry]]. He was elected Rector of [[Humboldt University of Berlin|Berlin University]] for 1921–1922. He set up an agency to channel government and private funds to young scientists and declined becoming Ambassador to the United States. For two unhappy years, he was the president of the ''Physikalisch-Technische Reichsanstalt'' (National Physical Laboratory), where he could not cope with the "mixture of mediocrity and red tape".<ref>Mendelssohn 1973, p. 138.</ref> In 1924, he became director of the ''Institute of Physical Chemistry'' at Berlin.

In 1927, the decrease in specific heat at low temperatures was extended to gases. He studied the theories of cosmic rays and cosmology.

Although a press release described him as "completely unmusical",<ref>Mendelssohn 1973, p. 139.</ref> Nernst developed an [[electric grand piano|electric piano]], the [[Neo-Bechstein|Neo-Bechstein-Flügel]] in 1930 in association with the [[C. Bechstein Pianofortefabrik|Bechstein]] and [[Siemens]] companies, replacing the [[sounding board]] with [[Valve amplifier|vacuum tube amplifiers]]. The piano used electromagnetic [[Pick up (music technology)|pickup]]s to produce electronically modified and amplified sound in the same way as an [[electric guitar]]. In fact, he was a pianist, sometimes accompanying Einstein's violin.{{Circular reference|date=April 2018}}