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==Biography==
==Biography==
Elsasser was born in 1904 to a Jewish family<ref>{{cite book|url=http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/elsasser-walter.pdf|title=Walter M. Elsasser, 1904—1991: A Biographical Memoir|first=Harry|last=Rubin|year=1995|publisher=National Academies Press|location=Washington DC}}</ref> in [[Mannheim]], [[Germany]]. Before he became known for his [[Dynamo theory|geodynamo theory]], while in [[Göttingen]] during the 1920s, he had suggested the experiment to test the wave aspect of [[electron]]s. This suggestion of Elsasser was later communicated by his senior colleague from Göttingen ([[Nobel Prize]] recipient [[Max Born]]) to physicists in [[England]]. This explained the results of the [[Davisson-Germer experiment|Davisson-Germer]] and [[George Paget Thomson|Thomson]] experiments later awarded with the [[Nobel Prize in Physics]]. In 1935, while working in Paris, Elsasser calculated the binding energies of protons and neutrons in heavy radioactive nuclei. [[Eugene Wigner|Wigner]], [[J. Hans D. Jensen|Jensen]] and [[Maria Goeppert-Mayer|Goeppert-Mayer]] received the Nobel in 1963 for work developing out of Elsasser's initial formulation. Elsasser therefore came quite close to a Nobel prize on two occasions.
Elsasser was born in 1904 to a Jewish family<ref>{{cite book|url=http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/elsasser-walter.pdf|title=Walter M. Elsasser, 1904—1991: A Biographical Memoir|first=Harry|last=Rubin|year=1995|publisher=National Academies Press|location=Washington DC}}</ref> in [[Mannheim]], [[Germany]]. Before he became known for his [[Dynamo theory|geodynamo theory]], while in [[Göttingen]] during the 1920s, he had suggested the experiment to test the wave aspect of [[electron]]s.<ref name=Ewald /> This suggestion of Elsasser was later communicated by his senior colleague from Göttingen ([[Nobel Prize]] recipient [[Max Born]]) to physicists in [[England]]. This explained the results of the [[Davisson-Germer experiment|Davisson-Germer]] and [[George Paget Thomson|Thomson]] experiments later awarded with the [[Nobel Prize in Physics]]. In 1935, while working in Paris, Elsasser calculated the binding energies of protons and neutrons in heavy radioactive nuclei. [[Eugene Wigner|Wigner]], [[J. Hans D. Jensen|Jensen]] and [[Maria Goeppert-Mayer|Goeppert-Mayer]] received the Nobel in 1963 for work developing out of Elsasser's initial formulation. Elsasser therefore came quite close to a Nobel prize on two occasions.


During 1946&ndash;47, Elsasser published papers describing the first mathematical model for the origin of the [[Earth's magnetic field]]. He conjectured that it could be a self-sustaining [[Dynamo theory|dynamo]], powered by convection in the liquid [[outer core]], and described a possible feedback mechanism between flows having two different geometries, [[toroidal and poloidal]] (indeed, inventing the terms). This had been developed from about 1941 onwards, partly in his spare time during his scientific war service with the [[U.S. Army Signal Corps]].<ref name="Beyler2008" />
During 1946&ndash;47, Elsasser published papers describing the first mathematical model for the origin of the [[Earth's magnetic field]]. He conjectured that it could be a self-sustaining [[Dynamo theory|dynamo]], powered by convection in the liquid [[outer core]], and described a possible feedback mechanism between flows having two different geometries, [[toroidal and poloidal]] (indeed, inventing the terms). This had been developed from about 1941 onwards, partly in his spare time during his scientific war service with the [[U.S. Army Signal Corps]].<ref name="Beyler2008" />

Revision as of 13:12, 11 May 2024

Walter Maurice Elsasser
Elsasser in 1989.
Born20 March 1904
Mannheim, Germany
Died14 October 1991 (1991-10-15) (aged 87)
Baltimore, United States
Known forDynamo theory
Complex system biology
AwardsNational Medal of Science (1987)
William Bowie Medal (1959)
Arthur L. Day Medal (1979)
Scientific career
FieldsPhysics
Theoretical biology
Doctoral advisorMax Born

Walter Maurice Elsasser (March 20, 1904 – October 14, 1991) was a German-born American physicist, a developer of the presently accepted dynamo theory as an explanation of the Earth's magnetism. He proposed that this magnetic field resulted from electric currents induced in the fluid outer core of the Earth. He revealed the history of the Earth's magnetic field by the study of the magnetic orientation of minerals in rocks.[1] He is also noted for proposing the wave-like diffraction of electron particles by a crystal; the observation of this effect led to a Nobel Prize in physics.[2]

The Olin Hall at the Johns Hopkins University has a Walter Elsasser Memorial in the lobby.

Biography

Elsasser was born in 1904 to a Jewish family[3] in Mannheim, Germany. Before he became known for his geodynamo theory, while in Göttingen during the 1920s, he had suggested the experiment to test the wave aspect of electrons.[2] This suggestion of Elsasser was later communicated by his senior colleague from Göttingen (Nobel Prize recipient Max Born) to physicists in England. This explained the results of the Davisson-Germer and Thomson experiments later awarded with the Nobel Prize in Physics. In 1935, while working in Paris, Elsasser calculated the binding energies of protons and neutrons in heavy radioactive nuclei. Wigner, Jensen and Goeppert-Mayer received the Nobel in 1963 for work developing out of Elsasser's initial formulation. Elsasser therefore came quite close to a Nobel prize on two occasions.

During 1946–47, Elsasser published papers describing the first mathematical model for the origin of the Earth's magnetic field. He conjectured that it could be a self-sustaining dynamo, powered by convection in the liquid outer core, and described a possible feedback mechanism between flows having two different geometries, toroidal and poloidal (indeed, inventing the terms). This had been developed from about 1941 onwards, partly in his spare time during his scientific war service with the U.S. Army Signal Corps.[4]

During his later years, Elsasser became interested in what is now called systems biology and contributed a series of articles to Journal of Theoretical Biology.[5][6][7][8][9][10][11] The final version of his thoughts on this subject can be found in his book Reflections on a Theory of Organisms, published in 1987 and again posthumously with a new foreword by Harry Rubin in 1998.

Elsasser died in 1991 in Baltimore, Maryland, US.

Biotonic laws

A biotonic law, a phrase invented by Elsasser, is a principle of nature which is not contained in the principles of physics.[12]

Biotonic laws may also be considered as local instances of global organismic or organismal principles,[13][14] such as the Organismic Principle of Natural Selection.[15][16]

Some, but not all, of Elsasser's theoretical biology work is still quite controversial, and in fact may disagree with several of the basic tenets of current systems biology that he may have helped to develop. Basic to Elsasser's biological thought is the notion of the great complexity of the cell. Elsasser deduced from this that any investigation of a causative chain of events in a biological system will reach a "terminal point", where the number of possible inputs into the chain will overwhelm the capacity of the scientist to make predictions, even with the most powerful computers. This might seem like a counsel of despair, but in fact Elsasser was not suggesting the abandonment of biology as a worthwhile research topic, but rather for a different kind of biology such that molecular causal chains are no longer the main focus of study. Correlation between supra-molecular events would become the main data source. Moreover, the heterogeneity of logical classes encompassed by all biological organisms without exception is an important part of Elsasser's legacy to both Complex systems biology and Relational Biology.[17]

Publications

  • Heat Transfer by Infrared Radiation in the Atmosphere. Harvard University. 1942. OCLC 10892935.
  • The Physical Foundation of Biology. An Analytical Study. London: Pergamon Press. 1958.
  • Atom and Organism. A New Approach to Theoretical Biology. Princeton University Press. 1966.
  • The Chief Abstractions of Biology. Amsterdam: North Holland. 1975.
  • Memoirs of a Physicist in the Atomic Age. New York: Science History Publications. 1978. ISBN 9780882021782. OCLC 3415166.
  • "The role of individuality in biological theory". Towards a Theoretical Biology vol.3. Edinburgh University Press. 1970.
  • Reflections on a Theory of Organisms. Holism in Biology. Johns Hopkins University Press. 1998.

Awards

Elsasser was elected to the National Academy of Sciences in 1957. From the American Geophysical Union he received the William Bowie Medal, its highest honor, in 1959; and the John Adam Fleming Medal (for contributions to geomagnetism) in 1971.[18][19] He received the Penrose Medal from the Geological Society of America in 1979 and the Gauss Medal from Germany in 1977.[4][20] In 1987, he was awarded the USA's National Medal of Science "for his fundamental and lasting contributions to physics, meteorology, and geophysics in establishing quantum mechanics, atmospheric radiation transfer, planetary magnetism and plate tectonics."[21]

See also

References

  1. ^ March 20 - Today in Science History - Scientists born on March 20th, died, and events
  2. ^ a b Ewald, P. P. (November 27, 1937). "Electron Diffraction in Crystals". Nature. 140: 928.
  3. ^ Rubin, Harry (1995). Walter M. Elsasser, 1904—1991: A Biographical Memoir (PDF). Washington DC: National Academies Press.
  4. ^ a b Beyler, Richard H.; Gatherer, Derek (2008). "Elsasser, Walter Maurice". Complete Dictionary of Scientific Biography. Vol. 20. Charles Scribner's Sons. pp. 378–381.
  5. ^ Elsasser, WM (1983). "Biological application of the statistical concepts used in the Second Law". Journal of Theoretical Biology. 105 (1): 103–16. Bibcode:1983JThBi.105..103E. doi:10.1016/0022-5193(83)90427-7. PMID 6656269.
  6. ^ Elsasser, WM (1982). "The other side of molecular biology". Journal of Theoretical Biology. 96 (1): 67–76. Bibcode:1982JThBi..96...67E. doi:10.1016/0022-5193(82)90156-4. PMID 7109657.
  7. ^ Elsasser, WM (1981). "Principles of a new biological theory: a summary". Journal of Theoretical Biology. 89 (1): 131–50. Bibcode:1981JThBi..89..131E. doi:10.1016/0022-5193(81)90182-X. PMID 7278305.
  8. ^ Elsasser, WM (1972). "A model of biological indeterminacy". Journal of Theoretical Biology. 36 (3): 627–33. Bibcode:1972JThBi..36..627E. doi:10.1016/0022-5193(72)90013-6. PMID 5080452.
  9. ^ Elsasser, WM (1969). "The mathematical expression of generalized complementarity". Journal of Theoretical Biology. 25 (2): 276–96. Bibcode:1969JThBi..25..276E. doi:10.1016/S0022-5193(69)80064-0. PMID 5383506.
  10. ^ Elsasser, WM (1964). "Synopsis of organismic theory". Journal of Theoretical Biology. 7 (1): 53–67. Bibcode:1964JThBi...7...53E. doi:10.1016/0022-5193(64)90040-2. PMID 5875342.
  11. ^ Elsasser, WM (1963). "Note on evolution in organismic theory". Journal of Theoretical Biology. 4 (2): 166–74. Bibcode:1963JThBi...4..166E. doi:10.1016/0022-5193(63)90025-0. PMID 5875158.
  12. ^ Pais, A. (1967). "Symmetries and Reflections. Scientific Essays. Eugene P. Wigner. Indiana University Press, Bloomington, 1967. 288 pp., illus". Science. 157 (3791): 911. Bibcode:1967Sci...157..911W. doi:10.1126/science.157.3791.911.
  13. ^ Baianu, I. C.; Brown, R.; Georgescu, G.; Glazebrook, J. F. (2006). "Complex Non-linear Biodynamics in Categories, Higher Dimensional Algebra and Łukasiewicz–Moisil Topos: Transformations of Neuronal, Genetic and Neoplastic Networks". Axiomathes. 16 (1–2): 65. doi:10.1007/s10516-005-3973-8. S2CID 9907900.
  14. ^ Łukasiewicz-Topos Models of Neural Networks, Cell Genome and Interactome Nonlinear Dynamic Models http://en.scientificcommons.org/23394472
  15. ^ Darwin, Charles; Wallace, Alfred Russel (1858). "On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection". Journal of the Proceedings of the Linnean Society of London. Zoology 3: 46–50.
  16. ^ Gatherer D: Finite universe of discourse. The systems biology of Walter Elsasser. The Open Biology Journal 2 4-15 Archived 2008-07-19 at the Wayback Machine
  17. ^ Baianu, I.C. 2006. "Robert Rosen's work and complex systems biology", Axiomathes, Vol. 16: 25-34; ISSN 1122-1151 https://doi.org/10.1007%2Fs10516-005-4204-z
  18. ^ "1959 William Bowie Medal - Past Recipients". Medals, Awards & Prizes. American Geophysical Union.
  19. ^ "1971 John Adam Fleming Medal - Past Recipients". Medals, Awards & Prizes. American Geophysical Union.
  20. ^ "Penrose Medalists". Past Award & Medaul Recipients. Geological Society of America. Retrieved 24 October 2011.
  21. ^ "The President's National Medal of Science: Recipient details – Walter Elsasser". National Science Foundation. 28 May 2009. Retrieved 24 October 2011.

Further reading

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