|Born||4 May 1879
Mogilev, Russian Empire
|Died||27 November 1944
|Doctoral advisor||Karl Ferdinand Braun|
|Doctoral students||Aleksandr Andronov,
Leonid Isaakovich Mandelstam or Mandelshtam (Belarusian: Леанід Ісаакавіч Мандэльштам, Russian: Леони́д Исаа́кович Мандельшта́м; IPA: [lʲɪɐˈnʲid isɐˈäkəvʲitɕ məndʲɪlʲˈʂtam] ( listen); May 4, 1879 – November 27, 1944) was a Soviet physicist of Belarusian-Jewish background.
Leonid Mandelstam was born in Mogilev, Russian Empire (now Belarus). He studied at the Novorossiya University in Odessa, but was expelled in 1899 due to political activities, and continued his studies at the University of Strasbourg. He remained in Strasbourg until 1914, and returned with the beginning of World War I. He was awarded the Stalin Prize in 1942. Mandelstam died in Moscow, USSR (now Russia).
The main emphasis of his work was broadly considered theory of oscillations, which included optics and quantum mechanics. He was a co-discoverer of inelastic combinatorial scattering of light used now in Raman spectroscopy (see below). This paradigm-altering discovery (together with G. S. Landsberg) had occurred at the Moscow State University just one week earlier than a parallel discovery of the same phenomena by C. V. Raman and K. S. Krishnan. In Russian literature it is called "combinatorial scattering of light" (from combination of frequencies of photons and molecular vibrations) but in English it is named after Raman.
Discovery of the combinatorial scattering of light
In 1918, Mandelstam theoretically predicted the fine structure splitting in Rayleigh scattering due to light scattering on thermal acoustic waves. Beginning from 1926, L.I. Mandelstam and G.S. Landsberg initiated experimental studies on vibrational scattering of light in crystals at the Moscow State University. As a result of this research, Landsberg and Mandelstam discovered the effect of the combinatorial scattering of light on 21 February 1928. They presented this fundamental discovery for the first time at a colloquium on 27 April 1928. They published brief reports about this discovery (experimental results with theoretical explanation) in Russian and in German and then published a comprehensive paper in Zeitschrift fur Physik.
In the same year of 1928, two Indian scientists C.V. Raman and K.S. Krishnan were looking for "Compton component" of scattered light in liquids and vapors. They found the same combinatorial scattering of light. Raman stated that "The line spectrum of the new radiation was first seen on 28 February 1928." Thus, combinatorial scattering of light was discovered by Mandelstam and Landsberg a week earlier than by Raman and Krishnan. However, the phenomenon became known as Raman effect.
Mandelstam founded one of the two major schools of theoretical physics in the Soviet Union (another being due to Lev D. Landau). In particular, he was mentor to Igor Y. Tamm, a Nobel Prize Laureate in Physics.
- L. I. Mandelshtam, I. E. Tamm "The uncertainty relation between energy and time in nonrelativistic quantum mechanics", Izv. Akad. Nauk SSSR (ser. fiz.) 9, 122-128 (1945). English translation: J. Phys. (USSR) 9, 249-254 (1945).
- Feinberg (2002)
- G.S. Landsherg, L.I. Mandelstam, "New phenomenon in scattering of light (preliminary report)", Journal of the Russian Physico-Chemical Society, Physics Section 60, 335 (1928).
- G. Landsberg, L.Mandelstam, "Eine neue Erscheinung bei der Lichtzerstreuung in Krystallen", Naturwissenschaften 16, 557 (1928).
- G.S. Landsherg, L.I. Mandelstam, "Uber die Lichtzerstreuung in Kristallen", Zeitschrift fur Physik 50, 769 (1928).
- Raman C.V., "A new radiation", Ind. J. Phys. 1928. V. 2. P. 387.
- Feinberg, E.L. (2002), "The forefather", Physics-Uspekhi, 45 (1), Bibcode:2002PhyU...45...81F, doi:10.1070/PU2002v045n01ABEH001126