Friedrich Georg "Fritz" Houtermans (January 22, 1903 – March 1, 1966) was a Dutch-Austrian-German atomic and nuclear physicist and Communist born in Zoppot (now Sopot) near Danzig (now Gdańsk), West Prussia to a Dutch father, who was a wealthy banker.

[3][4][5] While at Göttingen, Houtermans met Enrico Fermi, George Gamow, Werner Heisenberg, Wolfgang Pauli, and Victor Frederick Weisskopf.

[6][7] Their pioneering calculations were the impetus for Carl Friedrich von Weizsäcker and Hans Bethe, in 1939, to put forth the correct theory of stellar thermonuclear energy generation.

[3][4] Charlotte Riefenstahl, who received her doctorate in physics at the University of Göttingen in 1927, the same year as Houtermans and Robert Oppenheimer, was courted by both men.

During a physics conference at the Black Sea resort of Batumi, Riefenstahl and Houtermans were married in August 1930, in Tbilisi, with Wolfgang Pauli and Rudolf Peierls as witnesses to the ceremony.

They would later write a book together, Russian Purge and the Extraction of Confession,[22] under the pseudonyms of Beck and Godin to protect their many friends and colleagues back in the USSR.

[23] At the Forschunsinstitut Manfred von Ardenne, Houtermans showed that transuranic isotopes, such as neptunium and plutonium, could be used as fissionable fuels in substitution for uranium.

In an act of espionage against his country, Houtermans sent a telegram from Switzerland to Eugene Wigner at the Met Lab warning the USA's Manhattan Project of German work on fission: "Hurry up.

"[24] During Houtermans's employment at the Physikalisch-Technische Reichsanstalt (PTR), he got himself into serious trouble as a result of his habit of being a chain-smoker and suffering great distress if he did not have a supply of tobacco.

[25][26][27] As a result, Houtermans moved to Göttingen in 1945, where Hans Kopferman and Richard Becker got him positions at the Institut für Theoretische Physik and II.