Max von Laue

Max von Laue was a German physicist who won the 1914 Nobel Prize in Physics for showing that X-rays diffract when they pass through crystals. His scientific work also spanned optics, crystallography, quantum theory, superconductivity, and relativity. For four decades, he held administrative roles that shaped German science. He strongly opposed Nazism and helped rebuild German science after World War II.

Laue was born on 9 October 1879 in Pfaffendorf, near Koblenz, to Julius Laue and Minna Zerrenner. After finishing his Abitur in 1898, he served a year in the military, then studied mathematics, physics, and chemistry at the University of Strassburg. He moved to the University of Göttingen, where Woldemar Voigt and Max Abraham influenced him. After a semester at the University of Munich, he went to the University of Berlin in 1902. There, he studied under Max Planck, who had launched quantum theory in December 1900. Laue attended lectures by Otto Lummer on heat radiation and interference spectroscopy, which shaped his doctoral thesis on interference in plane-parallel plates; he earned his Ph.D. in 1903. He completed his habilitation under Arnold Sommerfeld at the University of Munich in 1906.

In 1906, Laue became a Privatdozent at the University of Berlin, where he first met Albert Einstein. Their friendship helped spread Einstein’s theory of relativity. Laue worked on entropy in radiation fields and the thermodynamic meaning of light-wave coherence. In 1909, he became a Privatdozent at the University of Munich. During the 1911 Christmas break and into January 1912, Paul Peter Ewald was finishing his doctoral thesis under Sommerfeld. While walking in Munich’s Englischer Garten, Ewald told Laue about his thesis, which dealt with visible light wavelengths much larger than the spacing in his crystal model. Laue asked what would happen with much smaller wavelengths. In June 1912, Sommerfeld reported to the Göttingen Physical Society that Laue, Paul Knipping, and Walter Friedrich had successfully diffracted X-rays at the University of Munich. This discovery won Laue the Nobel Prize in 1914. While in Munich, he also wrote the first volume of his relativity book (1910–1911).

In 1912, Laue became Professor of Physics at the University of Zurich, and in 1914 he was appointed Ordinarius Professor of Theoretical Physics at the University of Frankfurt. From 1916, he worked on vacuum tube development at the University of Würzburg for military telephony and wireless communication. From 1919 to 1943, he was Ordinarius Professor of Physics at the University of Berlin, alongside Walther Nernst, Fritz Haber, and James Franck. He helped organize the weekly Berlin Physics Colloquium, often sitting in the front row with Nernst and Einstein, who came from the Kaiser Wilhelm Institute for Physics (KWIP) in Berlin-Dahlem, where Einstein was director. Laue’s students included Leó Szilárd and Fritz London. He published the second volume of his relativity book in 1921.

As a consultant to the Physikalisch-Technische Reichsanstalt, Laue met Walther Meissner, who worked on superconductivity. Meissner discovered that a weak magnetic field rapidly drops to zero inside a superconductor (the Meissner effect). In 1932, Laue showed that the magnetic field threshold that destroys superconductivity depends on the shape of the body. He published twelve papers and a book on superconductivity, one paper co-authored with Fritz and Heinz London. Meissner wrote a biography of Laue in 1960.

The Kaiser Wilhelm Society, founded in 1911, supported research institutes. The KWIP was founded in 1914 with Einstein as director. Laue became a trustee of the KWIP in 1917, and in 1922 he was appointed deputy director, taking over administrative duties from Einstein. When Hitler became Chancellor in January 1933, Einstein was abroad and did not return. Laue then became acting director of the KWIP, a role he held until 1946 or 1948, except from 1935 to 1939, when Peter Debye was director. In 1943, the KWIP moved to Hechingen to avoid casualties. There, Laue wrote *Geschichte der Physik*, a history of physics later translated into seven languages.

Laue opposed Nazism generally and the "Deutsche Physik" movement specifically, which dismissed relativity as "Jewish physics." He called this ridiculous, saying science has no race or religion. With his close friend Otto Hahn, he secretly helped persecuted scientific colleagues emigrate from Germany. He also openly opposed antisemitism, as in an address on 18 September.