Walter M. Elsasser
Encyclopedia
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.
The Olin Hall at the Johns Hopkins University
has a Walter Elsasser Memorial in the lobby.
, 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 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
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 Meyer 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 1946-1947, 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 US 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 forward by Harry Rubin in 1998.
Elsasser died on October 14, 1991 in Baltimore
, United States
.
Biotonic laws may also be considered as local instances of global organismic or organismal principles, such as the Organismic Principle of Natural Selection.
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. Central to Elsasser's biological thought is the notion of the astronomical 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 calling for the abandonment of biology as a worthwhile research arena, but rather for a different kind of biology where molecular causal chains are no longer the main focus of study. Correlation between supra-molecular events would become the main data source. Moreover, the heterogenity 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
.
he received the Bowie Medal, its highest honor, in 1959; and the Fleming Medal (for contributions to geomagnetism) in 1971. He received the Penrose Medal
from the Geological Society of America
in 1979 and the Gauss Medal from Germany in 1977. In 1987, he was awarded the 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.".
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
-born American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
considered a "father" of the presently accepted dynamo theory
Dynamo theory
In geophysics, dynamo theory proposes a mechanism by which a celestial body such as the Earth or a star generates a magnetic field. The theory describes the process through which a rotating, convecting, and electrically conducting fluid can maintain a magnetic field over astronomical time...
as an explanation of the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's magnetism
Magnetism
Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...
. He proposed that this magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
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
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
in rocks.
The Olin Hall at the Johns Hopkins University
Johns Hopkins University
The Johns Hopkins University, commonly referred to as Johns Hopkins, JHU, or simply Hopkins, is a private research university based in Baltimore, Maryland, United States...
has a Walter Elsasser Memorial in the lobby.
Early life and career
Elsasser was born March 20, 1904, in MannheimMannheim
Mannheim is a city in southwestern Germany. With about 315,000 inhabitants, Mannheim is the second-largest city in the Bundesland of Baden-Württemberg, following the capital city of Stuttgart....
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
. Before he became known for his geodynamo theory
Dynamo theory
In geophysics, dynamo theory proposes a mechanism by which a celestial body such as the Earth or a star generates a magnetic field. The theory describes the process through which a rotating, convecting, and electrically conducting fluid can maintain a magnetic field over astronomical time...
, while in Göttingen
Göttingen
Göttingen is a university town in Lower Saxony, Germany. It is the capital of the district of Göttingen. The Leine river runs through the town. In 2006 the population was 129,686.-General information:...
in the 1920s, he has suggested the experiment to test the wave aspect of electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
s. This suggestion of Elsasser was later communicated by his senior colleague from Göttingen (Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
recipient Max Born
Max Born
Max Born was a German-born physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a number of notable physicists in the 1920s and 30s...
) to physicists in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. This explained the results of the Davisson-Germer
Davisson-Germer experiment
The Davisson–Germer experiment was a physics experiment conducted by American physicists Clinton Davisson and Lester Germer in 1927, which confirmed the de Broglie hypothesis. This hypothesis advanced by Louis de Broglie in 1924 says that particles of matter such as electrons have wave like...
and Thomson
George Paget Thomson
Sir George Paget Thomson, FRS was an English physicist and Nobel laureate in physics recognised for his discovery with Clinton Davisson of the wave properties of the electron by electron diffraction.-Biography:...
experiments later awarded with the Nobel Prize in Physics
Nobel Prize in Physics
The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others are the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and...
. In 1935, while working in Paris, Elsasser calculated the binding energies of protons and neutrons in heavy radioactive nuclei. Wigner, Jensen and Meyer 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 1946-1947, Elsasser published papers describing the first mathematical model for the origin of the Earth's magnetic field
Earth's magnetic field
Earth's magnetic field is the magnetic field that extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun...
. He conjectured that it could be a self-sustaining dynamo
Dynamo theory
In geophysics, dynamo theory proposes a mechanism by which a celestial body such as the Earth or a star generates a magnetic field. The theory describes the process through which a rotating, convecting, and electrically conducting fluid can maintain a magnetic field over astronomical time...
, powered by convection in the liquid outer core
Outer core
The outer core of the Earth is a liquid layer about 2,266 kilometers thick composed of iron and nickel which lies above the Earth's solid inner core and below its mantle. Its outer boundary lies beneath the Earth's surface...
, and outlined a feedback mechanism between flows having two different geometries, toroidal and poloidal
Toroidal and poloidal
The earliest use of these terms cited by the Oxford English Dictionary is by Walter M. Elsasser in the context of the generation of the Earth's magnetic field by currents in the core, with "toroidal" being parallel to lines of latitude and "poloidal" being in the direction of the magnetic field...
(indeed, coining the terms). This had been developed from around 1941 onwards, partly in his spare time during his scientific war service with the US Signal Corps.
In his later years, Elsasser became interested in what is now called systems biology
Systems biology
Systems biology is a term used to describe a number of trends in bioscience research, and a movement which draws on those trends. Proponents describe systems biology as a biology-based inter-disciplinary study field that focuses on complex interactions in biological systems, claiming that it uses...
and contributed a series of articles to Journal of Theoretical Biology
Journal of Theoretical Biology
The Journal of Theoretical Biology is a scientific journal about theoretical biology; dealing with theoretical issues, as well as mathematical and computational aspects of biology. Some research areas covered by the papers published in the journal are population genetics, morphogenesis,...
.
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 forward by Harry Rubin in 1998.
Elsasser died on October 14, 1991 in Baltimore
Baltimore
Baltimore is the largest independent city in the United States and the largest city and cultural center of the US state of Maryland. The city is located in central Maryland along the tidal portion of the Patapsco River, an arm of the Chesapeake Bay. Baltimore is sometimes referred to as Baltimore...
, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Biotonic laws
A biotonic law, a phrase coined by Elsasser, is a law of nature which cannot be contained in the laws of physics.Biotonic laws may also be considered as local instances of global organismic or organismal principles, such as the Organismic Principle of Natural Selection.
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
Systems biology
Systems biology is a term used to describe a number of trends in bioscience research, and a movement which draws on those trends. Proponents describe systems biology as a biology-based inter-disciplinary study field that focuses on complex interactions in biological systems, claiming that it uses...
that he may have helped to develop. Central to Elsasser's biological thought is the notion of the astronomical 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 calling for the abandonment of biology as a worthwhile research arena, but rather for a different kind of biology where molecular causal chains are no longer the main focus of study. Correlation between supra-molecular events would become the main data source. Moreover, the heterogenity of logical classes encompassed by all biological organisms without exception
is an important part of Elsasser's legacy to both Complex systems biology
Complex system biology
Complex systems biology is a branch or subfield of mathematical and theoretical biology concerned with complexity of both structure and function in biological organisms, as well as the emergence and evolution of organisms and species, with emphasis being placed on the complex interactions of, and...
and Relational Biology
Mathematical and theoretical biology
Mathematical and theoretical biology is an interdisciplinary scientific research field with a range of applications in biology, medicine and biotechnology...
.
Publications
- The Physical Foundation of Biology. An Analytical Study, (1958), Pergamon Press, London
- Atom and Organism. A New Approach to Theoretical Biology, (1966) Princeton University Press
- The Chief Abstractions of Biology, (1975), North Holland, Amsterdam.
- Memoirs of a Physicist in the Atomic Age, (1978)
- The role of individuality in biological theory, (1970) in Towards a Theoretical Biology vol.3 Edinburgh University Press
- Reflections on a Theory of Organisms. Holism in Biology, (1998) Johns Hopkins University PressJohns Hopkins University PressThe Johns Hopkins University Press is the publishing division of the Johns Hopkins University. It was founded in 1878 and holds the distinction of being the oldest continuously running university press in the United States. The Press publishes books, journals, and electronic databases...
(JHU).
Awards
Elsasser was elected to the National Academy of Sciences in 1957. From the American Geophysical UnionAmerican Geophysical Union
The American Geophysical Union is a nonprofit organization of geophysicists, consisting of over 50,000 members from over 135 countries. AGU's activities are focused on the organization and dissemination of scientific information in the interdisciplinary and international field of geophysics...
he received the Bowie Medal, its highest honor, in 1959; and the Fleming Medal (for contributions to geomagnetism) in 1971. He received the Penrose Medal
Penrose Medal
The Penrose Medal was created in 1927 by R.A.F. Penrose, Jr. as the top prize awarded by the Geological Society of America to those who advance the study of geoscience.-Award winners:* 2011 Paul F. Hoffman* 2010 Eric J. Essene* 2009 B. Clark Burchfiel...
from the Geological Society of America
Geological Society of America
The Geological Society of America is a nonprofit organization dedicated to the advancement of the geosciences. The society was founded in New York in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitchcock, John R. Proctor and Edward Orton and has been headquartered at 3300 Penrose...
in 1979 and the Gauss Medal from Germany in 1977. In 1987, he was awarded the National Medal of Science
National Medal of Science
The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral and social sciences, biology, chemistry, engineering, mathematics and...
"for his fundamental and lasting contributions to physics, meteorology, and geophysics in establishing quantum mechanics, atmospheric radiation transfer, planetary magnetism and plate tectonics.".
See also
- Complex system biologyComplex system biologyComplex systems biology is a branch or subfield of mathematical and theoretical biology concerned with complexity of both structure and function in biological organisms, as well as the emergence and evolution of organisms and species, with emphasis being placed on the complex interactions of, and...
- List of geophysicists
- Mathematical and theoretical biologyMathematical and theoretical biologyMathematical and theoretical biology is an interdisciplinary scientific research field with a range of applications in biology, medicine and biotechnology...
Further reading
- Extensive biography at The National Academies Press
- Gatherer D: Finite universe of discourse. The systems biology of Walter Elsasser. The Open Biology Journal 2 4-15
- Beyler R & Gatherer D (2007) Walter Elsasser (biography). In: Dictionary of Scientific Biography, new ed. New York: Charles Scribner's Sons Inc.
External links
- Oral History interview transcript with Walter Elsasser 29 May 1962, American Institute of Physics, Niels Bohr Library and Archives
- http://www.aip.org/history/ohilist/images/elsasser_walter_b1.jpg Active link to Dr. Walter Maurice Elsasser's photo