Carl Eckart

Carl Henry Eckart (May 4, 1902 in St. Louis, Missouri – October 23, 1973 in La Jolla, California) was an American physicist, physical oceanographer, geophysicist, and administrator. He co-developed the Wigner-Eckart theorem and is also known for the Eckart conditions in quantum mechanics. [ C. Eckart, "Some studies concerning rotating axes and polyatomic molecules", "Physical Review" 47 552-558 (1935).]

Education

Eckart began college in 1919 at Washington University in St. Louis where he received his B.S. and M.S. degrees with a major in engineering. However, due to Arthur Holly Compton, a physics faculty member and latter Chancellor, Eckart was influenced to continue his education in physics at Princeton, where he went in 1923 on an Edison Lamp Works Research Fellowship. Eckart was awarded his Ph.D. in 1925. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press] [ [http://lcweb2.loc.gov/cgi-bin/query/r?faid/faid:@field(DOCID+ms001014) Eckart Papers] – Library of Congress] [ [http://www.amphilsoc.org/library/guides/ahqp/ Author Catalog: Eckart] – American Philosophical Society]

During his graduate studies, Eckart co-authored a paper with Karl Compton, [ K. T. Compton and Carl Eckart "The Diffusion of Electrons Against an Electric Field in the Non-Oscillatory Abnormal Low Voltage Arc", "Phys. Rev." 25 (2) 139 - 146 (1925). Palmer Physical Laboratory, Princeton, New Jersey, Received 29 October 1924.] brother of Arthur Compton on low-voltage arcs, particularly the oscillatory phenomena arising in the diffusion of electrons against low-voltage fields. He continued this line of work after receipt of his Ph.D. on a National Research Council Fellowship at the California Institute of Technology (Caltech) during the period 1925 to 1927. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press]
Max Born, Director of the Institute for Theoretical Physics at the Georg-August University of Göttingen and co-developer of the matrix mechanics formulation of quantum mechanics with Werner Heisenberg, [ Heisenberg was granted his doctorate under Arnold Sommerfeld at the Ludwig Maximilians University of Munich in 1923 and completed his Habilitation under Max Born at the Georg-August University of Göttingen in 1924.] came to Caltech in the winter of 1925 and gave a lecture on his work. Born’s lecture gave Eckart the impetus to investigate the possible general operator formalism for quantum mechanics. Working into early 1926, Eckart developed the formalism. When Erwin Schrödinger’s first paper [ Erwin Schrödinger "(From the German) Quantization as an Eigenvalue Problem (First Communication)", "Annalen der Physik" 79 (4) 361-376, 1926. [English translation in Gunter Ludwig "Wave Mechanics" 94-105 (Pergamon Press, 1968) ISBN 08-103204-8] ] in the series of four [ Erwin Schrödinger "(From the German) Quantization as an Eigenvalue Problem (Second Communication)", "Annalen der Physik" 79 (6) 489-527, 1926. [English translation in Gunter Ludwig "Wave Mechanics" 106-126 (Pergamon Press, 1968) ISBN 08-103204-8] ] [ Erwin Schrödinger " (From the German) Quantization as an Eigenvalue Problem (Third Communication)", "Annalen der Physik" 80 (13) 437-490, 1926.] [ Erwin Schrödinger "(From the German) Quantization as an Eigenvalue Problem (Fourth Communication)", "Annalen der Physik" 81 (18) 109-139, 1926. [English translation in Gunter Ludwig "Wave Mechanics" 151-167 (Pergamon Press, 1968) ISBN 08-103204-8] ] on the wave mechanics formulation of quantum mechanics was published in January, Eckart soon realized that the matrix formulation and wave formulation of quantum mechanics were equivalent; he submitted his paper [ [http://www.pnas.org/cgi/reprint/12/7/473.pdf Eckart Paper] – Carl Eckart "The Solution of the Problem of the Simple Oscillator by a Combination of the Schrödinger and the Lanczos Theories", "Proceedings of the National Academy of Sciences of the United States of America" 12 473-476 (1926). California Institute of Technology. Communicated May 31, 1926.] to the "Proceedings of the National Academy of Sciences of the United States of America" for publication. However, it was communicated on May 31, 1926, and Schrödinger’s paper [ Erwin Schrödinger "Über das Verhältnis der Heisenberg-Born-Jordanschen Quantenmechanik zu der meinen" (Translated from the German: "On the Relationship of the Heisenberg-Born-Jordan Quantum Mechanics to Mine") "Annalen der Physik" 79 (8) 734-756, 1926. Received March 18, 1926. [English translation in Gunter Ludwig "Wave Mechanics" 127-150 (Pergamon Press, 1968) ISBN 08-103204-8] ] on the equivalence was received on March 18, 1926, thus giving him credit for the realization. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press] In 1927 Eckart received a Guggenheim Fellowship to do postdoctoral study and research with Arnold Sommerfeld at the Ludwig Maximilians University of Munich, one of the three main centers for the development of quantum mechanics, the others being Göttingen under Born and the University of Copenhagen under Niels Bohr. Also at Munich simultaneous with Eckart were Rudolf Peierls, and two other Guggenheim Fellows, Edwin C. Kemble and William V. Houston. [Arnold Sommerfeld "Some Reminiscences of My Teaching Career", "American Journal of Physics" 17 (5) 315-316 (1949)] [ [http://www.amphilsoc.org/library/guides/ahqp/bios.htm Sommerfeld Biography] – American Philosophical Society] In Munich, Eckart worked on the quantum mechanical behavior of simple oscillators using the Schrödinger equation and on operator calculus related to the matrix formulation of quantum mechanics. He also applied his work to the theory of electrons and the conductivity of metals using Fermi statistics, and he co-authored a paper [ A. Sommerfeld, W. V. Houston, and C. Eckart, "Zeits. f. Physik" 47, 1 (1928)] on the subject with Sommerfeld and William V. Houston. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press]

Career

University of Chicago

Returning to the United States in 1928, Eckart was appointed Assistant Professor in the Physics Department at the University of Chicago, where he continued his work on quantum mechanics for another 14 years. Noteworthy was a paper co-authored with Helmut Hönl, who received his doctorate under Sommerfeld in 1926; the paper, on the foundations of quantum mechanics, dealt with the role of group theory in quantum dynamics in monatomic systems and comparisons of the nuclear theories of Werner Heisenberg and Eugene Wigner. During this period, Eckart developed his formulation of the Wigner-Eckart theorem – a link between symmetry transformation groups applied to the Schrödinger equation and the laws of conservation of energy, momentum, and angular momentum. The theorem is particularly useful in spectroscopy. With F. C. Hoyt, Eckart translated [ Werner Heisenberg, Translated by Carl Eckart and F. C. Hoyt "The Physical Principles of the Quantum Theory" (Dover, 1930)] Heisenberg’s book on the physical principles of quantum mechanics. During the 1934-1935 academic year, Eckart took a sabbatical at the Institute for Advanced Study in New Jersey, as he also did in the academic years 1952-1953 and 1960-1961. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press] [ [http://lcweb2.loc.gov/cgi-bin/query/r?faid/faid:@field(DOCID+ms001014) Eckart Papers] – Library of Congress]

In December 1938 in Germany, Otto Hahn and Fritz Strassmann conducted an experiment which pointed towards the fission of uranium. They communicated their results to their former colleague Lisa Meitner, who had fled Germany earlier in the year. In January 1939, Meitner and her nephew Otto Frisch correctly interpreted the experimental results as the fission of uranium. News of the discovery spread very rapidly. With the potential of making a fission-based atomic weapon and the threat of war in Europe, this caused anxiety in many, Leó Szilárd for example, that Germany would develop an atomic weapon. As a result of two meetings with Albert Einstein, the first with Szilárd and Eugene Wigner and the second with Szilárd and Edward Teller, Einstein signed the Einstein-Szilárd letter to President Franklin Delano Roosevelt (FDR) in August. World War II broke out in Europe in September. The letter was delivered to FDR in October by economist and banker Alexander Sachs. In response to the letter, the Uranium Committee was formed that month. The Committee was organized into subsections by topic. The Theoretical Aspects Subsection, chaired by Enrico Fermi, was located at the University of Chicago, and Eckart was a member of it. [ [http://www.atomicarchive.com/Docs/SmythReport/smyth_iii.shtml Uranium Committee] ] However, in 1941, Eckart withdrew from the Committee because of his anti-atomic bomb sentiments. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press] [ [http://lcweb2.loc.gov/cgi-bin/query/r?faid/faid:@field(DOCID+ms001014) Eckart Papers] – Library of Congress]

University of California at San Diego

With the entry of the United States into WW II in December 1941, there was increased incentive for the scientific community to participate in the war effort. Axis submarines were exacting a toll on allied shipping, and university scientists were being approached by the U. S. Navy concerning optical and acoustical detection of submarines. B. O. Knudsen, director of the newly formed University of California Division of War Research, and his associate L. P. Delsasso approached Eckart for help. Eckart (an Associate Professor) took leave from the University of Chicago to work on the problem, thus beginning his 31-year stay in California. From 1942, he was assistant director of the Division of War Research, and eventually he was director, a position he held until 1946. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press] [ [http://lcweb2.loc.gov/cgi-bin/query/r?faid/faid:@field(DOCID+ms001014) Eckart Papers] – Library of Congress]

In 1946, Eckart officially resigned his position at the University of Chicago to become a professor of geophysics at the Scripps Institution of Oceanography of the University of California at San Diego (UCSD), a position he held until 1971. In 1946 he also became the first director of the Marine Physical Laboratory (MPL) of the University of California. The MPL was founded by Eckart, Roper Revelle, and Admiral Rawson Bennett to conduct geophysical research of common interest to the academic and naval communities. In 1948, the MPL became an integral part of the Scripps Institution of Oceanography, with Eckart serving as director until 1952. Eckart contributed to geophysics by linking theoretical hydrodynamic exercises to actual physical properties of water. In the following decades he did research on thermal layering in the ocean and atmospheres on which he wrote a book, the transmission of sound in the sea, turbulence, air-sea interactions, the generation and structure of surface, and internal ocean waves. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press] [ [http://lcweb2.loc.gov/cgi-bin/query/r?faid/faid:@field(DOCID+ms001014) Eckart Papers] – Library of Congress]

After WW II, Eckart collected his work and the work of others on underwater detection and published it a classified volume entitled "Principles and Applications of Underwater Sound", which was first published in 1946. It was declassified in 1954 and reprinted in 1968. It is a standard reference. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press]

During the period 1957 to 1959, Eckart was a member of the Editorial Advisory Board for the Johns Hopkins University Applied Physics Laboratory’s series on applied mathematics and mechanics. From 1959 through 1970, he was also a consultant for commercial enterprises such as General Dynamics Corporation and the Rand Corporation. [ [http://lcweb2.loc.gov/cgi-bin/query/r?faid/faid:@field(DOCID+ms001014) Eckart Papers] – Library of Congress]

From 1965 to 1967, Eckart was vice-chancellor for academic affairs at the UCSD. He then served the University of California, from 1967 to 1968, as alternate representative to the Institute for Defense Analyses, which was made up of 12 member universities and functioned as an independent source for studies and advice for the Department of Defense. [ [http://lcweb2.loc.gov/cgi-bin/query/r?faid/faid:@field(DOCID+ms001014) Eckart Papers] – Library of Congress]

Eckart contributed to the posthumous publication of some works by the mathematician John von Neumann. [ [http://lcweb2.loc.gov/cgi-bin/query/r?faid/faid:@field(DOCID+ms001014) Eckart Papers] – Library of Congress]

Personal

Eckart married Edith Louise née Frazee in 1926; they were divorced in 1948. In 1958, he married Klara Dan von Neumann, the widow of the mathematician John von Neumann; Klara died in 1963 in a drowning accident. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press] [ [http://lcweb2.loc.gov/cgi-bin/query/r?faid/faid:@field(DOCID+ms001014) Eckart Papers] – Library of Congress]

Honors

*1948 – Certificate of Merit signed by President Harry Truman

*1952 – Elected to the National Academy of Sciences

*1966 – Awarded the Alexander Agassiz Medal by the National Academy of Sciences for contributions to oceanography.

*1972 – Awarded the William Bowie Medal by the American Geophysical Union for outstanding contributions to fundamental geophysics.

Books

*Werner Heisenberg, Translated by Carl Eckart and F. C. Hoyt "The Physical Principles of the Quantum Theory" (Dover, 1930)

*Carl Eckart and others. "Principles and Applications of Underwater Sound" (NRDC, 1946). Originally a classified document and published as a "Summary Technical Report of Division 6", NDRC Volume 7, Washington, D.C., 1946. Declassified and distributed September 7, 1954. Reprinted and redistributed by Department of the Navy Headquarters Naval Material Command, Washington, D.C., 1968. [ [http://orsted.nap.edu/openbook.php?record_id=571&page=194 Eckart Biography] – The National Academies Press] [ [http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0200786 DTIC] ]

*Carl Eckart "Hydrodynamics of Oceans and Atmospheres" (Pergamon Press, 1960)

elected Literature

*Carl Eckart "The Solution of the Problem of the Simple Oscillator by a Combination of the Schrödinger and the Lanczos Theories", "Proceedings of the National Academy of Sciences of the United States of America" 12 473-476 (1926). Submitted 31 May 1926.

*Carl Eckart (National Research Fellow) "Operator Calculus and the Solution of the Equations of Quantum Dynamics", "Phys. Rev." 28 (4) 711 - 726 (1926). California Institute of Technology. Received 7 June 1926.

*A. Sommerfeld, W. V. Houston, and C. Eckart, "Zeits. f. Physik" 47, 1 (1928)

*Carl Eckart "The Application of Group theory to the Quantum Dynamics of Monatomic Systems", "Rev. Mod. Phys." 2 (3) 305 - 380 (1930). University of Chicago.

*Carl Eckart, "Some Studies Concerning Rotating Axes and Polyatomic Molecules", "Physical Review" 47 552-558 (1935).

*Carl Eckart "The Approximate Solution of One-Dimensional Wave Equations", "Rev. Mod. Phys." 20 (2) 399 - 417 (1948). University of California, Marine Physical Laboratory, San Diego, California.

References

*Arnold Sommerfeld "Some Reminiscences of My Teaching Career", "American Journal of Physics" 17 (5) 315-316 (1949)

Notes