David M. Dennison
Encyclopedia
David Mathias Dennison was an American physicist who made contributions to quantum mechanics
, spectroscopy
, and the physics of molecular structure.
, where he graduated in 1921. He then went to the University of Michigan
, in Ann Arbor, for graduate studies in physics with Walter F. Colby and Oskar Klein
. Klein, already associated with the Kaluza-Klein theory (1921), joined the faculty at Michigan in 1922, after a six-year stay at the Institute for Theoretical Physics, under Niels Bohr
, at the University of Copenhagen
. It was through Klein that Dennison heard and leaned much about the current theoretical physics being developed in Europe, which created a yearning in him to go to Copenhagen for further study. Dennison’s thesis was on the molecular structure and infrared spectrum of the methane molecule, and he was awarded his doctorate in 1924.
From 1924 to 1926, Dennison had an International Education Board (IEB) Fellowship to do postgraduate study and research in Europe. By the end of that time, Harrison McAllister Randall, chairman of physics department at the University of Michigan, had arranged for Dennison to stay in Europe another year on a University of Michigan fellowship. Dennison arrived at the Institute of Theoretical Physics at the University of Copenhagen, in October 1924. During his three years in Europe, he mostly did postdoctoral research in Copenhagen, where he had associations with other visiting physicists working there, such as Paul Dirac
, Samuel Abraham Goudsmit
, Werner Heisenberg
, Walter Heitler
, Ralph H. Fowler
, Friedrich Hund
, Hendrik Anthony Kramers
, Yoshio Nishina
, Wolfgang Pauli
, and George Eugene Uhlenbeck
. In the last half of 1925, Heisenberg and Max Born
published their matrix mechanics
formulation of quantum mechanics
. In the fall of 1926 he went to the University of Zurich
to study and work with Erwin Schrödinger
, who had early in the year published his papers on his wave mechanics
formulation of quantum mechanics. In early spring of 1927, Dennison went back to Copenhagen, and in late spring he went to the University of Cambridge
to work with Ralph Fowler for six weeks – there at the time were Ernest Rutherford
, Nevill Francis Mott
, Pyotr Kapitsa
, Patrick Blackett, and John Cockcroft
. The last few weeks of his fellowship were spent at the University of Leiden with Paul Ehrenfest
.
In 1925, George Eugene Uhlenbeck
and Samuel Abraham Goudsmit
had proposed spin
, and Wolfgang Pauli
had proposed the Pauli exclusion principle
. In 1926, Enrico Fermi
and Paul Dirac
introduced Fermi-Dirac statistics
. While at Cambridge, Dennison used quantum mechanicals calculations on molecular hydrogen to show that protons, like electrons, were subject to Fermi-Dirac statistics, or had spin-½
, and therefore obeyed the Pauli exclusion principle
.
had arrived at Michigan in 1926, and George Uhlenbeck and Samuel Goudsmit arrived in 1927. These four men were a team in developing theoretical physics, including quantum mechanics, for many years. They had been brought there by the chairman of the physics department, Harrison McAllister Randall, to build the theoretical capabilities of the department.
The David M. Dennison Building
on the campus of the University of Michigan was named in his honor.
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
, spectroscopy
Spectroscopy
Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
, and the physics of molecular structure.
Education
In 1917, Dennison entered Swarthmore CollegeSwarthmore College
Swarthmore College is a private, independent, liberal arts college in the United States with an enrollment of about 1,500 students. The college is located in the borough of Swarthmore, Pennsylvania, 11 miles southwest of Philadelphia....
, where he graduated in 1921. He then went to the University of Michigan
University of Michigan
The University of Michigan is a public research university located in Ann Arbor, Michigan in the United States. It is the state's oldest university and the flagship campus of the University of Michigan...
, in Ann Arbor, for graduate studies in physics with Walter F. Colby and Oskar Klein
Oskar Klein
Oskar Benjamin Klein was a Swedish theoretical physicist.Klein was born in Danderyd outside Stockholm, son of the chief rabbi of Stockholm, Dr. Gottlieb Klein from Homonna in Hungary and Antonie Levy...
. Klein, already associated with the Kaluza-Klein theory (1921), joined the faculty at Michigan in 1922, after a six-year stay at the Institute for Theoretical Physics, under Niels Bohr
Niels Bohr
Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. Bohr mentored and collaborated with many of the top physicists of the century at his institute in...
, at the University of Copenhagen
University of Copenhagen
The University of Copenhagen is the oldest and largest university and research institution in Denmark. Founded in 1479, it has more than 37,000 students, the majority of whom are female , and more than 7,000 employees. The university has several campuses located in and around Copenhagen, with the...
. It was through Klein that Dennison heard and leaned much about the current theoretical physics being developed in Europe, which created a yearning in him to go to Copenhagen for further study. Dennison’s thesis was on the molecular structure and infrared spectrum of the methane molecule, and he was awarded his doctorate in 1924.
From 1924 to 1926, Dennison had an International Education Board (IEB) Fellowship to do postgraduate study and research in Europe. By the end of that time, Harrison McAllister Randall, chairman of physics department at the University of Michigan, had arranged for Dennison to stay in Europe another year on a University of Michigan fellowship. Dennison arrived at the Institute of Theoretical Physics at the University of Copenhagen, in October 1924. During his three years in Europe, he mostly did postdoctoral research in Copenhagen, where he had associations with other visiting physicists working there, such as Paul Dirac
Paul Dirac
Paul Adrien Maurice Dirac, OM, FRS was an English theoretical physicist who made fundamental contributions to the early development of both quantum mechanics and quantum electrodynamics...
, Samuel Abraham Goudsmit
Samuel Abraham Goudsmit
Samuel Abraham Goudsmit was a Dutch-American physicist famous for jointly proposing the concept of electron spin with George Eugene Uhlenbeck in 1925.-Biography:...
, Werner Heisenberg
Werner Heisenberg
Werner Karl Heisenberg was a German theoretical physicist who made foundational contributions to quantum mechanics and is best known for asserting the uncertainty principle of quantum theory...
, Walter Heitler
Walter Heitler
Walter Heinrich Heitler was a German physicist who made contributions to quantum electrodynamics and quantum field theory...
, Ralph H. Fowler
Ralph H. Fowler
Sir Ralph Howard Fowler OBE FRS was a British physicist and astronomer.-Education:Fowler was initially educated at home but then attended Evans' preparatory school at Horris Hill and Winchester College...
, Friedrich Hund
Friedrich Hund
Friedrich Hermann Hund was a German physicist from Karlsruhe known for his work on atoms and molecules.Hund worked at the Universities of Rostock, Leipzig, Jena, Frankfurt am Main, and Göttingen....
, Hendrik Anthony Kramers
Hendrik Anthony Kramers
Hendrik Anthony "Hans" Kramers was a Dutch physicist.-Background and education:...
, Yoshio Nishina
Yoshio Nishina
was the founding father of modern physics research in Japan. He co-authored the well-known Klein–Nishina formula. He was a principal investigator of RIKEN and mentored generations...
, Wolfgang Pauli
Wolfgang Pauli
Wolfgang Ernst Pauli was an Austrian theoretical physicist and one of the pioneers of quantum physics. In 1945, after being nominated by Albert Einstein, he received the Nobel Prize in Physics for his "decisive contribution through his discovery of a new law of Nature, the exclusion principle or...
, and George Eugene Uhlenbeck
George Eugene Uhlenbeck
George Eugene Uhlenbeck was a Dutch-American theoretical physicist.-Background and education:George Uhlenbeck was the son of Eugenius and Anne Beeger Uhlenbeck...
. In the last half of 1925, Heisenberg and 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...
published their matrix mechanics
Matrix mechanics
Matrix mechanics is a formulation of quantum mechanics created by Werner Heisenberg, Max Born, and Pascual Jordan in 1925.Matrix mechanics was the first conceptually autonomous and logically consistent formulation of quantum mechanics. It extended the Bohr Model by describing how the quantum jumps...
formulation of quantum mechanics
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
. In the fall of 1926 he went to the University of Zurich
University of Zurich
The University of Zurich , located in the city of Zurich, is the largest university in Switzerland, with over 25,000 students. It was founded in 1833 from the existing colleges of theology, law, medicine and a new faculty of philosophy....
to study and work with Erwin Schrödinger
Erwin Schrödinger
Erwin Rudolf Josef Alexander Schrödinger was an Austrian physicist and theoretical biologist who was one of the fathers of quantum mechanics, and is famed for a number of important contributions to physics, especially the Schrödinger equation, for which he received the Nobel Prize in Physics in 1933...
, who had early in the year published his papers on his wave mechanics
Schrödinger equation
The Schrödinger equation was formulated in 1926 by Austrian physicist Erwin Schrödinger. Used in physics , it is an equation that describes how the quantum state of a physical system changes in time....
formulation of quantum mechanics. In early spring of 1927, Dennison went back to Copenhagen, and in late spring he went to the University of Cambridge
University of Cambridge
The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...
to work with Ralph Fowler for six weeks – there at the time were Ernest Rutherford
Ernest Rutherford
Ernest Rutherford, 1st Baron Rutherford of Nelson OM, FRS was a New Zealand-born British chemist and physicist who became known as the father of nuclear physics...
, Nevill Francis Mott
Nevill Francis Mott
Sir Nevill Francis Mott, CH, FRS was an English physicist. He won the Nobel Prize for Physics in 1977 for his work on the electronic structure of magnetic and disordered systems, especially amorphous semiconductors. The award was shared with Philip W. Anderson and J. H...
, Pyotr Kapitsa
Pyotr Kapitsa
Pyotr Leonidovich Kapitsa was a prominent Soviet/Russian physicist and Nobel laureate.-Biography:Kapitsa was born in the city of Kronstadt and graduated from the Petrograd Polytechnical Institute in 1918. He worked for over ten years with Ernest Rutherford in the Cavendish Laboratory in Cambridge...
, Patrick Blackett, and John Cockcroft
John Cockcroft
Sir John Douglas Cockcroft OM KCB CBE FRS was a British physicist. He shared the Nobel Prize in Physics for splitting the atomic nucleus with Ernest Walton, and was instrumental in the development of nuclear power....
. The last few weeks of his fellowship were spent at the University of Leiden with Paul Ehrenfest
Paul Ehrenfest
Paul Ehrenfest was an Austrian and Dutch physicist, who made major contributions to the field of statistical mechanics and its relations with quantum mechanics, including the theory of phase transition and the Ehrenfest theorem.- Biography :Paul Ehrenfest was born and grew up in Vienna in a Jewish...
.
In 1925, George Eugene Uhlenbeck
George Eugene Uhlenbeck
George Eugene Uhlenbeck was a Dutch-American theoretical physicist.-Background and education:George Uhlenbeck was the son of Eugenius and Anne Beeger Uhlenbeck...
and Samuel Abraham Goudsmit
Samuel Abraham Goudsmit
Samuel Abraham Goudsmit was a Dutch-American physicist famous for jointly proposing the concept of electron spin with George Eugene Uhlenbeck in 1925.-Biography:...
had proposed spin
Spin (physics)
In quantum mechanics and particle physics, spin is a fundamental characteristic property of elementary particles, composite particles , and atomic nuclei.It is worth noting that the intrinsic property of subatomic particles called spin and discussed in this article, is related in some small ways,...
, and Wolfgang Pauli
Wolfgang Pauli
Wolfgang Ernst Pauli was an Austrian theoretical physicist and one of the pioneers of quantum physics. In 1945, after being nominated by Albert Einstein, he received the Nobel Prize in Physics for his "decisive contribution through his discovery of a new law of Nature, the exclusion principle or...
had proposed the Pauli exclusion principle
Pauli exclusion principle
The Pauli exclusion principle is the quantum mechanical principle that no two identical fermions may occupy the same quantum state simultaneously. A more rigorous statement is that the total wave function for two identical fermions is anti-symmetric with respect to exchange of the particles...
. In 1926, Enrico Fermi
Enrico Fermi
Enrico Fermi was an Italian-born, naturalized American physicist particularly known for his work on the development of the first nuclear reactor, Chicago Pile-1, and for his contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics...
and Paul Dirac
Paul Dirac
Paul Adrien Maurice Dirac, OM, FRS was an English theoretical physicist who made fundamental contributions to the early development of both quantum mechanics and quantum electrodynamics...
introduced Fermi-Dirac statistics
Fermi-Dirac statistics
Fermi–Dirac statistics is a part of the science of physics that describes the energies of single particles in a system comprising many identical particles that obey the Pauli Exclusion Principle...
. While at Cambridge, Dennison used quantum mechanicals calculations on molecular hydrogen to show that protons, like electrons, were subject to Fermi-Dirac statistics, or had spin-½
Spin-½
In quantum mechanics, spin is an intrinsic property of all elementary particles. Fermions, the particles that constitute ordinary matter, have half-integer spin. Spin-½ particles constitute an important subset of such fermions. All known elementary fermions have a spin of ½.- Overview :Particles...
, and therefore obeyed the Pauli exclusion principle
Pauli exclusion principle
The Pauli exclusion principle is the quantum mechanical principle that no two identical fermions may occupy the same quantum state simultaneously. A more rigorous statement is that the total wave function for two identical fermions is anti-symmetric with respect to exchange of the particles...
.
Career
In 1927, upon Dennison’s return from Europe, he started his life-long career at the University of Michigan until 1976. Otto LaporteOtto Laporte
Otto Laporte was a German-born American physicist who made contributions to quantum mechanics, electromagnetic wave propagation theory, spectroscopy, and fluid dynamics...
had arrived at Michigan in 1926, and George Uhlenbeck and Samuel Goudsmit arrived in 1927. These four men were a team in developing theoretical physics, including quantum mechanics, for many years. They had been brought there by the chairman of the physics department, Harrison McAllister Randall, to build the theoretical capabilities of the department.
The David M. Dennison Building
David M. Dennison Building
The David M. Dennison Building is a building located on the University of Michigan campus in Ann Arbor, Michigan.The building is located at 500 Church Street. It was built in 1963 by Albert Kahn, and stands twelve stories in height. It is a brick building with a modern style. Twelve floors are...
on the campus of the University of Michigan was named in his honor.
Selected Literature
- David M. Dennison The Molecular Structure and Infra-Red Spectrum of Methane, The Astrophysical Journal 62 84 (1925)
- David M. Dennison The Rotation of Molecules, Phys. Rev. 28 (2) 318 - 333 (1926). Institute for Theoretical Physics, Copenhagen, Denmark, Received 27 April 1926.
- David M. Dennison A Note on the Specific Heat of the Hydrogen Molecule Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character Vol. 115, No. 771 pp. 483-486 (1927). Communicated by R. H. Fowler; received 3 June 1927.
- David M. Dennison The Infrared Spectra of Polyatomic Molecules Part I, Rev. Mod. Phys. 3 (2) 280 - 345 (1931). University of Michigan.
- David M. Dennison The Infra-Red Spectra of Polyatomic Molecules. Part II, Rev. Mod. Phys. 12 (3) 175 - 214 (1940). University of Michigan, Ann Arbor, Michigan.
- David M. Dennison, Recollections of Physics and of Physicists During the 1920s, Am. J. Phys. 42 1051-1056 (1974)