Leonid Isaakovich Mandelstam or Mandelshtam ( be, Леанід Ісаакавіч Мандэльштам; rus, Леонид Исаакович Мандельштам, p=lʲɪɐˈnʲit ɨsɐˈakəvʲɪtɕ mənʲdʲɪlʲˈʂtam, a=Ru-Leonid_Mandelstam.ogg, links=y; 4 May 1879 – 27 November 1944) was a Soviet physicist of

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- Jewish background.

Life

Leonid Mandelstam was born in Mogilev, Russian Empire (now Belarus). He studied at the Novorossiya University in

Odessa Odesa (also spelled Odessa) is the third most populous city and municipality in Ukraine and a major seaport and transport hub located in the south-west of the country, on the northwestern shore of the Black Sea. The city is also the administrativ ...

, 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).

Scientific achievements

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 ''combinational

scattering Scattering is a term used in physics to describe a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including ...

of light'' used now in

Raman spectroscopy Raman spectroscopy () (named after Indian physicist C. V. Raman) is a spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. Raman sp ...

(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 ''"combinational scattering of light"'' (from combination of frequencies of photons and molecular vibrations) but in English it is named after Raman.

Discovery of the combinational scattering of light

In 1918, Mandelstam theoretically predicted the

fine structure In atomic physics, the fine structure describes the splitting of the spectral lines of atoms due to electron spin and relativistic corrections to the non-relativistic Schrödinger equation. It was first measured precisely for the hydrogen atom ...

splitting in Rayleigh scattering due to light scattering on thermal acoustic waves. Beginning from 1926, Mandelstam and 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 combinational 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 some attempt at a theoretical explanation) in Russian and in German and then published a comprehensive paper in '' Zeitschrift für Physik''. In the same year, two Indian scientists C. V. Raman and K. S. Krishnan also observed the inelastic scattering of light. Raman stated that "The line spectrum of the new radiation was first seen on 28 February 1928". Thus, combinational scattering of light was observed by Mandelstam and Landsberg a week earlier than by Raman and Krishnan. However, according to the Physics Nobel Committee, Mandelstam and Landsberg were unable to provide an independent, complete interpretation for the discovery, as they only later cited Raman's article. Also, their observations were limited to crystals, whereas Raman and Krishnan showed the effect in solids, liquids, and vapors, thus proving the universal nature of the effect. Raman's method was further applied with great success in different fields of molecular physics, for example in the composition analysis of liquids, gases, and solids, and provided significant insight on nuclear spins. Hence, the light-scattering phenomenon became known as Raman scattering or the Raman effect. The L.I.Mandelshtam's lectures in optics dated by 1944 can be considered as the formal beginning of the second stage of the DNG- metamaterials theory.Slyusar V.I. Metamaterials on antenna solutions.// 7th International Conference on Antenna Theory and Techniques ICATT’09, Lviv, Ukraine, October 6-9 2009. - Pp. 20

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Scientific school and legacy

Mandelstam founded one of the two major schools of theoretical physics in the Soviet Union (another being due to

Lev D. Landau Lev Davidovich Landau (russian: Лев Дави́дович Ланда́у; 22 January 1908 – 1 April 1968) was a Soviet- Azerbaijani physicist of Jewish descent who made fundamental contributions to many areas of theoretical physics. His a ...

). In particular, he was mentor to Igor Y. Tamm, a Nobel Prize Laureate in Physics who in turn was a mentor to Vitaly Ginzburg who also received a Nobel Prize in Physics and Andrey Sakharov, the "father of Soviet hydrogen bomb" and a Nobel Peace Prize Laureate. A crater on the far side of the Moon is named after Mandelshtam.

Selected publications

* L. I. Mandelshtam,

I. E. Tamm Igor Yevgenyevich Tamm ( rus, И́горь Евге́ньевич Тамм , p=ˈiɡərʲ jɪvˈɡʲenʲjɪvitɕ ˈtam , a=Ru-Igor Yevgenyevich Tamm.ogg; 8 July 1895 – 12 April 1971) was a Soviet physicist who received the 1958 Nobel Prize in ...

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).

References

External links

* * Y.L. Alpert
''Tribute to the Scientific School of L.I. Mandelshtam''
* Sergei I. Vavilov
''Obituary to academician L.I. Mandelstam'', 1945
{{DEFAULTSORT:Mandelshtam, Leonid Isaakovich 1879 births 1944 deaths People from Mogilev Jews from the Russian Empire Belarusian Jews Soviet Jews Belarusian physicists Soviet physicists Soviet inventors Moscow State University alumni Full Members of the USSR Academy of Sciences Stalin Prize winners Jewish physicists University of Strasbourg alumni Optical physicists