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Born on this day
Adolf Butenandt
Adolf Friedrich Johann Butenandt (24 March 1903 – 18 January 1995) was a German biochemist and member of the Nazi party. He was awarded the Nobel Prize in Chemistry in 1939 for his "work on sex hormones."
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Important personalitiesBack

Peter Debye24.3.1884

Wikipedia (11 Mar 2013, 14:31)
Peter Joseph William Debye ForMemRS (March 24, 1884 – November 2, 1966) was a Dutch physicist and physical chemist, and Nobel laureate in Chemistry.


Early life

Born Petrus Josephus Wilhelmus Debije in Maastricht, Netherlands, Debye attended the Aachen University of Technology, Rhenish Prussia just 30 km away in 1901. He studied mathematics and classical physics, and, in 1905, received a degree in electrical engineering. In 1907, he published his first paper, a mathematically elegant solution of a problem involving eddy currents. At Aachen, he studied under the theoretical physicist Arnold Sommerfeld, who later claimed that his most important discovery was Peter Debye.

In 1906, Sommerfeld received an appointment at Munich, Bavaria, and took Debye with him as his assistant. Debye got his Ph.D. with a dissertation on radiation pressure in 1908. In 1910, he derived the Planck radiation formula using a method which Max Planck agreed was simpler than his own.

In 1911, when Albert Einstein took an appointment as a professor at Prague, Bohemia, Debye took his old professorship at the University of Zurich, Switzerland. This was followed by moves to Utrecht in 1912, to Göttingen in 1913, to ETH Zurich in 1920, to Leipzig in 1927, and in 1934 to Berlin, where, succeeding Einstein, he became director of the Kaiser Wilhelm Institute for Physics (now named the Max-Planck-Institut) whose facilities were built only during Debye's era. He was awarded the Lorentz Medal in 1935. From 1937 to 1939 he was the president of the Deutsche Physikalische Gesellschaft.


Scientific contributions

His first major scientific contribution was the application of the concept of dipole moment to the charge distribution in asymmetric molecules in 1912, developing equations relating dipole moments to temperature and dielectric constant. In consequence, the units of molecular dipole moments are termed debyes in his honor. Also in 1912, he extended Albert Einstein's theory of specific heat to lower temperatures by including contributions from low-frequency phonons. See Debye model.

In 1913, he extended Niels Bohr's theory of atomic structure, introducing elliptical orbits, a concept also introduced by Arnold Sommerfeld. In 1914–1915, Debye calculated the effect of temperature on X-ray diffraction patterns of Crystal crystalline solids with Paul Scherrer (the "Debye–Waller factor"). In 1923, together with his assistant Erich Hückel, he developed an improvement of Svante Arrhenius' theory of electrical conductivity in electrolyte solutions. Although an improvement was made to the Debye-Hückel equation in 1926 by Lars Onsager, the theory is still regarded as a major forward step in our understanding of electrolytic solutions. Also in 1923, Debye developed a theory to explain the Compton effect, the shifting of the frequency of X-rays when they interact with electrons.


Later work

From 1934 to 1939 Debye was director of the physics section of the prestigious Kaiser Wilhelm Institute in Berlin. From 1936 onwards he was also professor of Theoretical Physics at the Frederick William University of Berlin. These positions were held during the years that Adolf Hitler ruled Nazi Germany and, from 1938 onward, also over Austria.

In 1939 Debye traveled to the United States of America to deliver the Baker Lectures at Cornell University in Ithaca, New York. After leaving Germany in early 1940, Debye became a professor at Cornell, chaired the chemistry department for 10 years, and became a member of Alpha Chi Sigma. In 1946 he became an American citizen. Unlike the European phase of his life, where he moved from city to city every few years, in the United States Debye remained at Cornell for the remainder of his career. He retired in 1952, but continued research until his death.

Much of Debye's work at Cornell concerned the use of light-scattering techniques (derived from his X-ray scattering work of years earlier) to determine the size and molecular weight of polymer molecules. This started as a result of his research during World War II on synthetic rubber, but was extended to proteins and other macromolecules.

In April 1966, Debye suffered a heart attack, and in November of that year a second one proved fatal. He is buried in the Pleasant Grove Cemetery (Ithaca, New York, USA).


   
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