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Walter Maurice Elsasser (March 20, 1904 – October 14, 1991) was a German-born American physicist considered a "father" 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 through pioneering the study of the magnetic orientation of minerals in rocks.〔(March 20 - Today in Science History - Scientists born on March 20th, died, and events )〕 The Olin Hall at the Johns Hopkins University has a Walter Elsasser Memorial in the lobby. ==Biography== Elsasser was born in 1904 in Mannheim, Germany. Before he became known for his geodynamo theory, while in Göttingen in the 1920s, he has suggested the experiment to test the wave aspect of electrons. 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. Over 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 outlined a feedback mechanism between flows having two different geometries, toroidal and poloidal (indeed, coining the terms). This had been developed from around 1941 onwards, partly in his spare time during his scientific war service with the U.S. Army Signal Corps.〔 In his later years, Elsasser became interested in what is now called systems biology and contributed a series of articles to Journal of Theoretical Biology.〔 〕 〔 〕 〔 〕 〔 〕 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, USA. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Walter M. Elsasser」の詳細全文を読む スポンサード リンク
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