Michigan and the first Atomic Clock

Michigan and the First Atomic Clock

Jens Zorn,
Randall Laboratory of Physics, University of Michigan, Ann Arbor, MI 48109-1040

The first atomic clock has its origins with the research done at the University of Michigan and by its graduates over the years 1912-1948.

Although the current (2012) standard of time/frequency is based on a 9 GHz microwave transition in cesium, the first device that one could really call an atomic clock was designed and built in 1948 by Harold Lyons (UM physics PhD 1939) at the National Bureau of Standards. This clock, which predates the first cesium clock by four years, was based on the 24 GHz microwave transition in the ammonia (NH3) molecule. The existence of this transition was predicted by David Dennison in 1932; it was discovered in 1934 when the Michigan experimentalists Neil Williams and Claud Cleeton developed the magnetron tubes to produce the necessary radiation to perform the first-ever microwave spectroscopy.

But the story begins even earlier.
The theoretical understanding of the ammonia molecule rests on the experimental work started by Harrison Randall when he returned to Michigan in 1911 after working for a year on the infrared spectroscopy of atoms in Paschen’s laboratory in Tübingen. Randall built his own infrared spectrometer and initially studied some unresolved questions on the barium atom.
Then in 1913 from Berlin, Eva von Bahr published spectra arising from vibrational transitions in HCl, spectra with indications of a fine structure that was conjectured to arise from molecular rotation. Randall, whose spectrometer had a higher resolution than von Bahr’s, realized that he could resolve the question of whether molecular rotation was quantized in the same way that Bohr had assumed for electrons in his 1913 theory of the atom. Randall then directed the Michigan infrared effort toward molecules, first to diatomic molecules and then to small polyatomic molecules including NH3. The issue of quantized rotation was soon settled by Elmer Imes whose thesis experiments on HCl proved definitive , but it took longer to understand ammonia. By 1929, Barker had finally established the dimensions of the NH3 pyramid, and subsequent measurements of its spectra by Dennison and Hardy, and later by Wright and Randall, determined values for the doublet splitting of the vibrational states.
A theoretical calculation by Dennison and Uhlenbeck (1932) confirmed the dimensions and energies in this double minimum problem, however their paper does not explicitly mention the possibility of observing a microwave transition in NH3. Rather it appears that Dennison was the one who made the suggestion in 1932 that UM Professor Neil Williams and his students look for the absorption of 24 GHz radiation.


Photo of Dennison explaining to Ray Van Ausdal the focusing and state selecting action of a quadrupole field for  focusing a beam of NH3 molecules.  Dennison’s theory was the basis for the first Maser as built by Gordon, Zeiger and Townes in 1954.

In the early 1930s, no one had been able to produce controllable frequencies higher than 8 GHz with vacuum tubes, but Neil Williams had been engaged with the physics and engineering of vacuum tubes since 1924-5 during his time on leave at the General Electric laboratories in Schenectady. There Williams had worked under the guidance of A. W Hull, a pioneer in the development of the magnetron as a vacuum tube for generating very high frequencies. After his return from Schenectady, Williams did research at Michigan on aspects of electron emission but he did not particularly concentrate on high frequency generation.
Fortunately, Williams responded with enthusiasm to Dennison’s suggestion: He set Claud Cleeton, his graduate student who was already well-versed in research, to the task of building a magnetron to generate radiation of appropriately high frequency. Cleeton succeeded; he and Williams then built spectrometer to look at the absorption of microwaves by a gas of ammonia molecules. The successful results of this experiment, the first microwave spectroscopy ever done, were reported in 1934.
(Cleeton and Williams continued their development of magnetrons and by 1936 had pushed the limit for high frequency generation by vacuum tubes to 45 GHz, a new record; this led to Cleeton getting a wartime assignment to do radar development at the Naval Research Laboratory in Washington, DC )

"NH3"   --- a sculpture commemorating Michigan's discovery of microwave spectroscopy

“NH3” — a sculpture by Jens Zorn commemorating Michigan’s discovery of microwave spectroscopy

Harold Lyons was a graduate student in the Michigan Physics Department over the years 1934-39 doing a PhD thesis under the direction of Professor Ora Duffendack (who had also been in Schenectady in 1924-5). Lyons graduated in 1939 and went from Michigan to work at the Naval Research Laboratory for two years; he then joined the National Bureau of Standards and was soon chosen as chief of the Microwave Standards Section. Lyons’s familiarity with frequency standards together with the post-war availability of microwave hardware led him to build a clock based on the 24 GHz transition in ammonia. This clock consisted of a quartz crystal oscillator that was stabilized to the absorption frequency of a 8-meter-long tube filled with ammonia gas. The signal from the oscillator was then divided down to a frequency appropriate to drive an ordinary electric clock that was mounted on the front of the apparatus. This ammonia clock, the first atomic clock, was built by Lyons and his staff in the NBS Laboratories; it became operational in August of 1948,
It turns out that pressure broadening and power dependence of the 24 GHz transition limited the 1948 ammonia clock’s precision to parts in 10E+8, this not really improving on carefully-built quartz oscillator frequency standards. For increased precision it seemed promising (as suggested by Rabi and others) to base a clock on transitions observed in atomic beam spectrometer. Several laboratories (including a collaboration between Lyons of NBS and Kusch of Columbia) began working on a cesium beam clocks, and some of these became operational in early 1953. By 1967 their improved precision (parts in 10E+12) and their reliability led to the adoption of the 9 GHz hyperfine transition in cesium as the international standard of frequency. At this writing (2012), the best cesium clocks approach the 10E+16 level of precision, but it appears that optical transitions in trapped beryllium ions may offer almost two orders of magnitude improvement for the standard of time/frequency.
Given the relatively close interactions among the Michigan graduate students and faculty in the mid-1930’s, it is quite likely that Lyons knew much about Cleeton’s thesis already in 1934; moreover, after leaving Michigan both men had overlapping time in the Naval Research Laboratory in Washington, DC. Both worked on radar systems during WWII and in the immediate postwar years. (I am now looking for correspondence or other evidence that they might have had discussions of the NH3 absorption during their time in the Washington area — evidence that would link Cleeton more directly than he already is to the development of the atomic clock.)

Comment: The term “atomic clock” is here regarded as describing a timekeeper or frequency standard that uses a resonance in either an atom or a molecule, either neutral or ionized, as a reference pendulum
It is interesting to note that as ammonia was being eclipsed as a frequency standard in 1952, its very large electric dipole moment made it the molecule of choice in 1954 when Gordon, Zeiger and Townes used it as the working molecule in the first maser

Dennison on the writing of scientific papers

(from an interview conducted by Thomas Kuhn on Jan 28, 1964.   http://www.aip.org/history/ohilist/4570_2.html

CONTEXT:  As a graduate student, Dennison had requested to do his thesis research in theoretical physics (this would be the first theory Ph.D. granted by Michigan).    Guided by Walter Colby and Oskar Klein,  Dennison developed the theory to understand the infrared spectrum of methane, a project that fit well with the experimental work being done by Randall, Barker, Sleator, and others in the Michigan physics laboratories.   During the interview, Dennison told Kuhn:

At this time (1923) Oskar Klein suggested that I write a preliminary version [of the  methane paper] which I would send on to Copenhagen. . . .  I was sure that I was pretty good about writing. I was positive that I knew how to write. So I wrote a version of the thing up, and Klein sat down with me, and every single sentence was wrong, had to be revised and changed. ‘Exactly what do you mean by this, and what’s the shade of meaning here?’ and so on. Everything, piece by piece. I remember at one session I was beginning to be a little annoyed. I said finally, “Professor Klein, you would write it one way; I will write it another way. This is my way of writing it.” Klein said, “This is nonsense. There’s only one way to write a paper. If you have something to say, there is only one way; there are no two ways of writing it.” This actually, to a certain extent, was so banged into my head that I tend to believe it. I tend to believe it now that a good paper is one in which — in a sense it’s a little bit like an analytic function — each sentence has a little bit of what was past and a little bit of what is coming, so that from a portion of it you almost can reconstruct the rest. This is an exaggeration, of course. But, nevertheless, there is really only one way of writing well.

Harrison M. Randall

Harrison McAllister Randall (1970-1969) was an American physicist whose leadership over the years 1915-1941 brought the University of Michigan to international prominence for its research in experimental and theoretical physics.

Prior to 1910, the Michigan Physics Department had been focused on precision metrology.  Indeed Randall, who took all of his degrees at Michigan, had measured the coefficient of expansion of quartz for his own 1902 PhD thesis prior to his appointment to the Michigan faculty.  But a sabbatical year (1910-11) spent in Tübingen, Germany exposed him to the astonishing range of developments in modern physics; guided by Friedrich Paschen, Randall became expert in the methods of infrared spectroscopy and decided it was a promising area for development in Ann Arbor.

It was not long before Randall and his Michigan collaborators produced molecular spectra of unprecedented quality and detail.   At that time Walter Colby was the only resident theorist, so,with Randall’s encouragement,  Colby recruited Oskar Klein.  Although Klein returned to Europe after two years, the importance of theoretical colleagues was by then firmly established and it was arranged to have Otto Laporte, Samuel Goudsmit,  George Uhlenbeck, and David Dennison added to the physics faculty.   Also it was Colby’s insight and Randall’s enthusiasm that started the Michigan Summer Symposia in Theoretical Physics, an annual (1927-1941), multi-week gathering that provided short courses from prominent theorists (Bohr, Dirac, Fermi, Heisenberg, Pauli, …) to audiences that  sometimes exceeded 100 auditors.

Meanwhile, Randall also oversaw Michigan’s substantial growth in atomic physics and nuclear physics; in the mid 1930s he found the resources to build a cyclotron that was, for a time, the most energetic in the world.

Randall was elected to the presidency of the American Physical Society in 1937.  He remained as chairman of the Michigan physics department until his retirement in 1941 but continued for another 25 years to explore the use of infrared spectroscopy in biophysics.




Harrison M. Randall, On the Coefficient of Expansion of Quartz,  Phys Rev 20.   Pp 1-37.  (1905)  (this is a refinement of his 1902 thesis experiment)

H. M. Randall,  Infrared  Spectroscopy at Michigan,  Journal of the Optical Society of America, Vol. 44, pp 97-103  (1954)   (overview of work in Ann Arbor)

H. H. Nielsen, A Half-Century of Infrared Spectroscopy,  Journal of the Optical Society of America, Vol. 50, p. 1147  (1960)   (Ives medal encomium for Harrison M. Randall)

H. M. Randall and D. W. Smith,  Infrared  Spectroscopy in Biological Research,  Journal of the Optical Society of America, Vol. 53,   1086-1092  , (example of work done after his retirement)

Development of Biophysics at Michigan

 On the Development of Biophysics at The University of Michigan

 by Samuel Krimm
Professor Emeritus of Physics and Research Scientist Emeritus of Biophysics
University of Michigan, Ann Arbor, Michigan
June, 2011

Biophysics has had a long history at the University of Michigan, from its beginnings in the research of faculty members of the Department of Physics in the 1940s, through efforts to establish a department in 1950, toward the final success in establishing a University institute in 1960, and to the present formation in the College of Literature, Science and the Arts (LSA) of an Enhanced Program in Biophysics (which is equivalent to a department) in 2009. My aim here is to provide an account of the early activities, which center around the research of major individuals and their persistent actions to establish viable academic biophysics units at the University.

Individual Biophysical Research

The early development of interest in melding the disciplines of physics and biology centered on the research of scientists, primarily in the Department of Physics. It is therefore important to know the history of this evolution, particularly in its elements of marrying the fundamentals and techniques of physics with the desire to answer basic questions in biology.

Detlev Bronk. Although the most substantive efforts in biophysical studies began in the 1940s, it would be amiss not to note the singular emergence of this disciplinary vision that is associated with Detlev Bronk   This future president both of the National Academy of Sciences and of the  Rockefeller Institute of Medical Research started his scientific career at the University of Michigan. Although he enrolled in 1921 in the graduate program in Physics, working on studies of the infrared absorption of hydrogen chloride, by 1923 he was attracted to the idea of physical investigations of physiological mechanisms, encouraged by Chairman Harrison Randall “…in the belief that there is a large and undeveloped field in the investigation of physical laws in living organisms and [who] said that he would be glad to have such work carried on in his department…” (Brink, Jr., 1978).  Bronk went on to study physiology and, with Robert Gesell, published seven papers on physiological properties of the respiratory and cardiovascular systems and neural excitation of secretion from the salivary glands in mammals. In 1926 he received the Ph.D. in Physics and Physiology, the first of its kind in the nation.

Bronk’s subsequent research career continued with biophysical studies of physiological processes, and his advocacy of the discipline manifested itself in the transition of the Rockefeller Institute to Rockefeller University.

H. Richard Crane. After getting his Ph.D. at Cal Tech and doing a post-doc there, Crane came to Michigan in 1935 and soon built an accelerator to continue his research in nuclear physics.  Because of the Medical School interest in the biological effects of radiation, he started a seminar on this topic and even pursued his incipient interest in biology by attending courses in biochemistry and physiology. In the early 1940s the Bacteriology Department acquired an electron microscope with funding from the Rackham Graduate School with the proviso that the Physics Department install and run it, which naturally fell to Crane. To help visualization, he “…asked [Robley Williams] if he could evaporate a little metal onto the bacteria and viruses that were to be photographed in the electron microscope, and wondered what they would look like. The effect was striking. They looked three-dimensional.” (Crane, 1997). By 1945 Crane had perfected a shadow casting unit for the microscope, which Williams would exploit in his work.

After the war, Crane maintained activity in the biophysical area. In a paper on “Principles and Problems of Biological Growth” (Crane, June1950) he enunciated a basic idea: “The attachment of one [unit of a structure] to another was always done in exactly the same way, geometrically…The first and most striking thing to be noted in the models is that all of them take the form of a screw, or helix, which winds around a straight axis.” It is intriguing to wonder if this article influenced Linus Pauling in his seminal proposals of basic protein chain structures, since he states in his first of many papers on the subject (Pauling, Corey, Branson, April 1951) that “Hence, the only configurations for a chain compatible with our postulate of equivalence of the residues are helical configurations.” After the 1953 Watson and Crick discovery of the double-helical structure of DNA many scientists engaged in discussions of its biophysical properties, one of which was the 1956 Crane and Cyrus Levinthal (of the Physics Department) physical analysis of the proposed  unwinding of the two strands during replication. Even though he no longer worked in this area, Crane maintained an interest in the development of biophysics at Michigan.

Robley C. Williams. Williams came to Michigan in 1935 as an Assistant Professor of Astronomy, was recruited in 1941 for war work (during which he was introduced to viruses), and returned to Michigan in 1945 as Associate Professor of Physics. His work on evaporating  an aluminum coating for telescope mirrors was what induced Crane to approach him on evaporating some on viruses for possible visualization enhancement. In 1945, together with Ralph W. G. Wyckoff of the UM Department of Epidemiology, Williams  published the first electron shadow micrograph of the tobacco mosaic virus protein (Williams and Wyckoff, 1945), the forerunner of his many subsequent contributions to the study of the structure of this and other viruses.

Williams left in 1950 for Berkeley to continue his virus studies. In 1957 he was elected the first President of the recently formed Biophysical Society.

Cyrus Levinthal. After a Ph.D. at Berkeley and coming to Michigan in 1950, Levinthal turned his attention to biophysical studies. This resulted in the above-mentioned work with Crane and in an important paper on the mechanism of DNA replication (Levinthal, 1956). In this work he used 32P labeling to demonstrate that, as the replication proceeds from an initially fully labeled DNA reproducing in a non-labeled cell growing in a non-labeled medium, the label is fully retained in one strand of the double helix rather than being dispersed among the growing strands. This provided strong support for the complementary replication mechanism suggested by the double-helix DNA structure of Watson and Crick.

Levinthal left Michigan for MIT in 1957 and in 1968 he joined Columbia University as the Chairman of its newly-established Department of Biological Sciences. In subsequent work he stimulated considerations of the dynamics of how protein molecules fold into their biologically active form (“Levinthal’s paradox,” which points out that if the protein samples all possible conformations before finding its native structure it would require a time longer than the age of the universe); and he was the first to develop the basis of computer imaging of the three-dimensional structures of biological molecules.

Gordon B. B. M. Sutherland.    Joining the Physics faculty in 1949, the eminent British scientist Gordon Sutherland quickly built one of the most prominent and diverse infrared  spectroscopy laboratories in this country, thus continuing Michigan’s traditional strength in infrared research that had started when Randall returned from Tübingen in 1911.

Among the areas of research were macromolecular systems, including synthetic polymers and a continuation of his studies on biological systems. This was still the era of interpretation based on so-called group frequencies that were derived from complete analyses of the spectra of relevant small molecules, and is represented in his review on “Infrared Analysis of the Structures of Amino Acids, Polypeptides and Proteins” (Sutherland, 1952). At this point it did not seem feasible to obtain for such large molecules as polymers and proteins the kind of physical insights into structure provided by the normal mode analysis that could be implemented for small molecules. Nevertheless, Sutherland provided important continuity to the long-standing Michigan excellence in the field of infrared spectroscopy established by Randall, and he set the stage for the coming challenges to apply normal mode analysis to understanding the structure-spectrum correlations in macromolecules.

Sutherland left Michigan in 1956 to become director of England’s National Physical Laboratory and in 1964 he became Master of Emmanuel College in Cambridge.

Samuel Krimm. One of the postdoctoral fellows in Sutherland’s group was Samuel Krimm, who came in 1950 to study the infrared spectra of synthetic polymers. His initial goal was to investigate the then-unexplored far infrared region, which was accessible only at Michigan with a far-infrared vacuum spectrometer built in 1936 by Randall to obtain the long-wavelength rotation spectrum of water. Krimm’s subsequent research involved obtaining experimental spectra of a range of polymers and implementing normal mode analyses for such systems based on force fields developed from small-molecule analogs. These studies led to a deeper understanding of fundamental aspects of the structure and interactions in polymers like polyethylene and polyvinyl chloride. It was this capability that induced Krimm in the early 1970s to extend his earlier preliminary studies on protein spectra into an extensive program of normal mode analyses of the infrared and Raman spectra of polypeptides. The results of this research were summarized in a comprehensive and much-quoted review on “Vibrational Spectroscopy and Conformation of Peptides, Polypeptides, and Proteins” (Krimm, 1986). This area remained a major  component of his ongoing research program, of which other biophysically related studies included: circular dichroism investigations of the supposedly “random” chain structure of denatured proteins in solution; and theoretical studies to improve the physical accuracy of classical (so-called molecular mechanics) potential energy functions used for structure and dynamics calculations on proteins by requiring agreement with force-dependent properties such as vibrational spectra in addition to the (then-restricted) agreement with energy-dependent properties such as structure.

Others. In 1948 Harrison Randall (at the age of 78!) began a series of infrared studies on compounds found in viruses and bacteria, and was publishing papers on this work well into his 80s. Richard Sands arrived in Michigan in 1957 and soon after started his electron paramagnetic resonance and Mössbauer studies of cytochrome oxidase and other biologically important molecules.

During his 1961-69 tenure, Charles R. Worthington embarked on incisive small-angle x-ray studies of molecular organization in collagen, muscle, and nerve myelin.

After the phase-out in the mid-1970s of the department’s cyclotron and the termination of its local research program, William Parkinson turned to studies of the effects of electromagnetic radiation on biological systems.   C. Tristram Coffin shifted his interests from particle physics to biophysics.

Academic Biophysics Units

It should be clear from the above descriptions that merging the disciplines of physics and biology was embedded from the earliest times in the vision of many members of the Department of Physics. The major players also felt strongly that the key to progress in achieving this goal would depend on a parallel effort by the University to establish an academic base for defining the discipline, developing the training of students, and promoting the acquisition of financial support for research programs. As the following chronology attests, this was not to be achieved in a timely manner, dedicated people left, and it is clear that Michigan failed to capitalize on the revolution in molecular biology that was started by the 1953 discovery of the DNA double helix.


6/1949   Dean Ralph Sawyer announces the establishment of a “doctoral degree Program
in Biophysics” in the Graduate School and appoints Robley Williams as the
chairman of its implementation committee.

12/1949  Williams transmits to Dean Sawyer the Program’s recommendation for the
Ph. D. in Biophysics. Its approval remained the basis for the degree.

1950       A decision is made to create a Department of Biophysics starting in the 1950-51
academic year, but the action is rescinded by the Regents following the
resignation of Williams in June to go to Berkeley, attracted there by the virus
work  of Wendell Stanley and the opportunity to join the newly created
Department of Virology. A bachelor’s concentration in biophysics is established
in the Physics Department.

1/1951    Following the departure of Williams, Dean Hayward Keniston of LSA asks
Sutherland to “reactivat[e] a program in biophysics” by “creating a
committee which would serve to coordinate all of the interests in the field.”

7/1951    Sutherland organizes a “Summer Symposium on Biophysics” at the University.
Speakers include Salvatore Luria, J. Lawrence Oncley, Paul Doty, Ernest
Pollard, and Max Delbruck.

11/1951  Sutherland, for the Committee on Biophysics, recommends to the Division of
Biological Sciences “the early establishment of a Laboratory of Biophysics in
the Physics Department with a separate allocation of funds.”

1954       A group of physics professors, supported by Chairman Ernest Barker, submits a
proposal to the Administrative Officers “to sanction the formation of a
Biophysics Research Unit as a separate entity in the University.” Although “it
would not be expected that it would be given any appropriation…it should
receive due consideration in future appropriations… for research.”

9/1955    The Regents, on request of the Department of Physics, establish in the Graduate
School a Biophysics Research Center “to encourage research in biophysics and
to administer funds provided for research in biophysics.” Sutherland is named
Director of the Center.

9/1955    The Biophysics and Biophysical Chemistry Study Section of NIH sponsors a
“Conference on the Status of Biophysics” at the University “to discuss mutual
research and administrative problems with leaders in the general area of

7/1956    A “Summer Symposium on Biophysics” is held at the University. Speakers
include Francis Crick, James Watson, Alex Rich, Erwin Chargaff, David
Harker, Cyrus Levinthal, Gunther Stent, Seymour Benzer, Fancois Jacob,
Joshua Lederberg, Sol Spiegelman, Felix Haurowitz, and many others.

12/1958  Following the departures of Sutherland and Levinthal, Samuel Krimm is
appointed Director of the Biophysics Research Center.

1/1960    An application by Krimm to NIH for a graduate training grant is rejected,
with the following  comments: “ The University of Michigan’s early venture
into physical biology was well known as well as are more recent difficulties
which have been experienced. The failure of physical biology to develop and
flourish was a source of great concern to our consultants and a cause for inquiry
into why the environment was not a propitious one. [Our] consultants were of
the opinion that [the Biophysics Committee] was in reality largely a paper
structure which could not exercise the strong and continuing leadership in
support of the proposed program which is so necessary for its success.” The
Center decides to urge substantive University commitment to biophysics and
the search for an eminent outside Director.

5/1960    Evolving from the impact of the NIH decision, and following intensive
discussions by the Director and members of the Center with the administration,
Dean Roger Heyns of LSA and Dean William Hubbard of the Medical School,
with the concurrence of Dean Sawyer, submit a proposal to transfer the Center
to the newly formed Institute of Science and Technology (IST). They propose
that about “$75,000 of Institute funds be allocated to the support of the Center,
to be used primarily to secure one major appointment in biophysics and several
younger appointments and to provide initial research support for [these].”

6/1960    The above proposal is formalized, presented to the Regents, and accepted by
them to reorganize the Center as the Biophysics Research Division (BRD) of
IST, under the Office of the Vice-President for Research, with a Director.

6/1960    Based on earlier studies by the Center, Dugald Brown (Zoology) and Horace
Davenport (Physiology) prepare an application to NIH, submitted by Dean
Sawyer, for a Health Research Facilities Grant. Approval permits construction
of the BRD wing of the IST building on North Campus. A committee to choose
a director is formed.

9/1960   The committee to choose a Director of BRD first meets, with David Dennison
of Physics as Chairman and Dean Heyns as a member.

1961       Oncley accepts the University’s offer of the position of Director.

1962       Oncley arrives in Ann Arbor to assume the position of Director of BRD. The
Biophysical Society, established in 1957 with Robley Williams as its first
President, elects Oncley as its fourth President.

1963       The BRD wing in IST is occupied, including laboratories of several faculty
groups that Oncley brings from Harvard as well as  those of the Michigan
groups of Krimm and Sands.

1964       An NIH Training Grant in Biophysics, with Oncley as Director, is awarded for a
5-year period to support the Ph. D. program, and is renewed in 1969.

It is evident that, with the establishment of the Biophysics Research Division, the discipline of biophysics becomes embedded in the academic structure of the University. Its later history is another story, but it may be worth noting some highlights.

1) Interdisciplinary Chairs: Krimm (Physics) 1976-86; Martha Ludwig (Biological Chemistry), 1982-83, 86-89, 95-96; John Langmore (Biology), 1989-95; Rowena Matthews (Biological Chemistry), 1996-2001; Erik Zuiderweg (Chemistry, Biological Chemistry), acting chair 2001-02; James Penner-Hahn (Chemistry), 2002-07; Duncan Steel (Electrical Engineering, Physics), 2007-08; Jens-Christian Meiners (Physics), 2008-.

2) Financial Support: In addition to the University’s traditional funding of faculty salaries and other administrative support for BRD, the Executive Officers approve in 1985 the establishment of a Program in Protein Structure and Design, with Krimm as Director, that includes funding for future additional BRD faculty appointments, many of them in Physics. In 1986 the Program receives a $940,000 award from the State of Michigan’s Research Excellence and Economic Development Fund, a portion of which is used to provide new and improved equipment in BRD.

3) Division Move. In the interest of being located closer to participating departments, BRD is moved in 1993 from the IST building on North Campus into renovated space on the third and fourth floors of the 1908 wing of the Chemistry building on Central Campus. The move proves beneficial in all respects.

4) Organizational Change. In view of the increasing role of teaching in the BRD mission, Provost Paul Courant initiates in 2005 a study of whether Biophysics should be more appropriately placed as a department within LSA. This results in 2009 in the creation of LSA Biophysics, an Enhanced Program with tenure-appointing power, and the inclusion of the Undergraduate Biophysics Concentration, formerly in Physics, with Meiners as its Chair. Progress to Departmental status is envisioned, a hopeful end to a 60-year journey. 


Brink, Jr., F. (1978) National Academy of Sciences Memoir, p. 10.

Crane, H. R. (1950) Scientific Monthly 70, 376-389.

Crane, H. R. (1997) Personal Recollections.

Krimm, S. (1986) Adv. Protein Chem. 38, 181-364.

Levinthal, C. (1956) Proc. Nat. Acad. Sci. 42, 394-404.

Pauling, L., Corey, R. B., Branson, H. R. (1951) Proc. Nat. Acad. Sci. 37, 205-211.

Sutherland, G. B. B. M. (1952) Adv. Prot. Chem. 7, 291-318.

Williams, R. C., Wyckoff, R. W. G. (1945) Science 101, 594-596.

Walt Gray

Walt Gray joined the UM physics department in 1964 after finishing his PhD at the University of Colorado. First appointed as a research associate, he soon moved to the teaching faculty as instructor (1965), assistant professor (1966) and then to associate professor in 1970,

In the late 1960s and early 1970s, Gray, together with Robert Tickle and John Bardwick, under the general direction of William Parkinson, developed a high-resolution magnetic spectrometer for use with the University of Michigan’s 82-inch cyclotron that was one of the few accelerators in the world capable of high-resolution nuclear spectroscopy. Gray and his students made a major improvement to the spectrometer by developing a position-sensitive, silicon-diode, focal-plane detector array. This permitted electronic acquisition and analysis of data in experiments that tested the collective model of nuclei proposed by Benjamin Mottelson and Aage Bohr. In particular, Gray and his doctoral student Karl Erb did studies of 205Bi and 207Bi by Proton-Transfer Reactions. (Erb later went on to a distinguished career that included directorship of the NSF program in nuclear physics and then, for many years, directorship of the NSF’s Office of Polar Programs. )

In the early years of nuclear physics, physicists very often did their experiments with accelerators associated with their own university; this was the case at Michigan. But in the mid-1970s the pattern for nuclear physics shifted to one already established by particle physicists in which experiments were more and more often done at national laboratories. Walt was involved in this; in 1980-82 he was on the executive committee of the Indiana University Cyclotron Facility users’ group. But at this time he was also responding more and more strongly to the department’s need for dedicated undergraduate teaching and advising.. Indeed, he and Robert Tickle become the anchors of the introductory physics courses, much as Wally McCormick and Wilbur Peters had been in a previous decade. Walt committed himself to undergraduates with notable success: His book Introduction to Modern Physics was published by Addison Wesley. He received Michigan’s Ruth Sinclair Award for Counseling in 1988 and, quite remarkably, its Excellence in Education Award three years in a row. He remained a strong contributor to the department’s teaching until his retirement at the end of the 2001-2002 academic year.

.                                                                                       JCZ

Nobel Prize winners with Michigan connections (1)

A half-dozen winners of the Nobel Prize in Physics have worked at Michigan:

Crane: electrons & positrons (1)

In this post we begin recollections of Dick Cranes’s work with electrons and positrons   The material here is in augmentation of, or as commentary on the biographical memoirs of  Crane already in the literature.  In particular, we’ll be able to present many more photographs than are in that literature.

Crane’s work on the racetrack electron synchrotron began just after WWII when he urged David Dennison and Ted Berlin to confirm theoretically that electrons could be confined in stable orbits that included some straight line sections.   A display model shows the overall concept

But a view of the accelerator under construction shows the realities:

The Michigan electron synchrotron under construction, ~1950.

. Ten years later, Crane’s focus was completely on measurement of the free electron’s gyromagnetic ratio:

Bill Williams-Hydrogen (1)

Bill Williams did his PhD at Yale and was persuaded by Peter Franken, Dick Sands and Jens Zorn to join the Michigan physics department in 1965. Williams immediately started an ambitious program of experiments in atomic physics. This included a re-examination of the fine structure of atomic hydrogen to resolve issues that arose when Richard Robiscoe’s measurements of the Lamb shift (done at Chicago for his 1964 PhD thesis and then again in 1965 when he was a postdoc at Yale) gave results that differed significantly with the then-accepted value. Robiscoe then came to Michigan in 1966 to join Williams in a new hydrogen experiment; their apparatus is shown here:

The magnetic fields for these experiments, produced by water-cooled coils mounted externally to the vacuum system, had to be stable and well-controlled. homogeneous over the region traversed by the beam. Those fields were produced by water-cooled coils mounted on the outside of the vacuum system. The photograph below shows Tong Shyn, then a graduate student, straddling the bed of a lathe in the student shop as he winds the magnet’s coil. He is spattered by the heavy varnish used to keep the copper conductors in place.

[Ater finishing his dissertation with Williams, Shyn moved to the University of Michigan’s Space Physics Research Laboratory where he and his students did a long series of elegant experiments on electron-atom collisions in order to measure cross sections needed for modeling of the atmosphere.]

Robiscoe left Michigan in 1969 to accept a position at the University of Montana in Bozeman. Within a few years experiments of a different sort were yielding a more reliable value of the Lamb shift. But Williams did not lose interest in atomic hydrogen; in fact he and Robert Lewis began to see a way to test for the violation of parity in this simplest of atoms. We will tell that long and complicated story in a further installments.

Sanders: at Weinreich retirement

Weinreich Retirement Dinner
Remarks-T. M. Sanders
7 April, 1995


Those few of you who are of a certain age may remember a book and television series of the early 1950s called “I Led Three Lives.” I have known Gabi for a very long time, but I have not known all of his lives. I have learned what I know of his early life in bits, gleaned from conversations over the years. Gabi spent nearly thirteen years of his life in Vilna, then geographically in Poland, now Vilnius, capital of Lithuania.

His father, Max Weinreich was director of the YIVO, an institution devoted to the language, culture and literature of Yiddish, Gabi’s first tongue. The family had a cook with whom Gabi also spoke, in what he later learned was a different language, Polish. He grew up in a richly cultured, secular, socialist Jewish family in a larger Jewish culture, embedded in an urban environment. In September 1939, the Germans invaded Poland from the West and the Russians from the East. Vilna was in the Eastern portion, occupied by the Soviets. Gabi once told me that he had heard on Soviet radio that Stalin was the world’s greatest skier. I recall speculating with him whether he was a theoretical or experimental skier.

In late 1940, Gabi’s father and older brother attended a conference in Sweden, and went from there directly to the United States. Gabi and his mother remained in Vilna, awaiting documents which would permit them to emigrate. As I learned ten years ago, when I was bitten by a dog on the eve of my wedding, Gabi was bitten by a neighbor’s dog while they were awaiting the papers. He was given the Pasteur rabies treatment (The dog actually was rabid.), the papers arrived, and he and his mother departed. Their route took them to Moscow, on the Trans-Siberian railroad to Vladivostok (an eleven day journey), to Yokohama, San Francisco, and then to New York, where the family was re-united in early 1941. Hitler invaded the USSR the following June. The society of Gabi’s childhood was “disappeared.”

Gabi spent his teens in the Washington Heights section of Manhattan (near the George Washington bridge). He started school knowing practically no English (On this point I have only his word; actually I am skeptical.) He took phonetic notes, which his brother (a linguist) helped him decipher. One of his early recollections is hearing a teacher declare, “The United States is a capitalist country.” Startled, Gabi looked around to see if anyone else noticed what she had confessed. He, after all, knew that this was true, but he was amazed to find that anyone would admit such a thing.

He was an undergraduate at City College and at Columbia, which brings me to the point when we first met.

Columbia Days

He and I began graduate school at Columbia in the Fall of 1948. I am not certain whether we met that first semester, when I was still supported by the GI Bill, and did not have an office at the Pupin Lab. I became a Teaching Assistant the next term, and Gabi and I arranged to share an office (with Andy Sessler) the following Fall. I remember Gabi walking into the office with a Russian book he had found in a bookstore. (Russian was another language he “did not know.”) The book was Landau and Lifshitz’s Classical Theory of Fields. We were absolutely stupefied by Landau’s elegant (and totally new to us) treatment of Relativity.

In the Fall of 1949 we began our research, he with I. I. Rabi and I with C. H. Townes. Both of us began working with younger physicists, recent doctorates: Gabi with Vernon Hughes, and I with Arthur Schawlow. Our labs were three doors apart on the tenth floor of Pupin. Gabi’s lab, and the atomic beam machine he inherited, had just given the result which first showed the electron to have an anomalous magnetic moment.

Rabi was a formidable figure, and dominated the department in many ways. He was actually chairman only in our first years there, but remained the dominant personality much longer. Henry Foley used to say that at the Faculty Club, the physics people had two types of luncheon conversation. If Rabi was absent, the topic was Rabi. If not, there was some difficulty finding a topic until Rabi chose one. He seemed to find it necessary to dominate and intimidate everyone in the department-students and faculty alike. The first person who could deal with him was Jack Steinberger who, along with Robert Serber, arrived at Columbia in the 1950s as part of the exodus from Berkeley over a loyalty oath. Steinberger (never overburdened by politeness) and Rabi were overheard by a student in a conversation which went like this:
Rabi: I don’t know about that.
Steinberger: Well I do.
(end of conversation)

The late 1940s were past the time Rabi considered the “Golden Age” of his physics. He was, nonetheless, still a very creative thinker. He was also involved, at the time, in fateful decisions in the “corridors of power.” In the Fall of 1949, he was a member of the General Advisory Committee of the Atomic Energy Commission which recommended against a “Crash Program” to develop a Hydrogen Bomb. This recommendation was to play a key role in the loyalty hearings “In the Matter of J. Robert Oppenheimer” in the Spring of 1954. It was reading Rabi’s testimony in that affair that first made me appreciate his strengths.

Experiments, in those days, had a good deal of glass apparatus, and we both learned a certain amount of glass blowing (as did our slightly senior colleague, Peter Franken). When Gabi needed a professional, he called on Karl Schumann, the University glassblower. Karl was a temperamental artist, who spoke a colorful, heavily-accented, English, referring to his colleagues as “neon sign benders.” Gabi’s experiment used 3He (Rabi obtained 3 NTP cc of gas for him.), for which a Gabi bought a commercial glass mercury diffusion pump. It was a glorious object, very large, and full of jets, water jackets, and spirals for the returning mercury. A group of us gathered around when the day came for Schumann to glassblow the pump into the apparatus. Karl preferred to work in front of an audience, and invited one into his shop at the end of each work day. The great man arrived, put down his tools, and walked slowly and silently around the marvelous new pump. Then he turned to Gabi and said, “What did you pay for this piece of crap?”

At Columbia, Gabi first taught a course in Physics of Music. He amazed me, in demonstrating the asymmetric nature of the transient produced by a piano, by playing a piece of classical music backwards, recording it, and playing the tape backwards. The music was then forward, but each note was time-reversed. The notes sounded the way a harmonica does if one inhales rather than blowing.

Bell Labs

In 1953 Gabi completed his Ph.D. and went to Bell Labs, where he was interviewed and hired by William Shockley (who had entertained a Columbia colloquium by playing “How Dry I Am” on an audio oscillator made with a germanium transistor and powered by a battery made of a couple of coins and some damp paper).

His Bell Labs physics which I know best is something called the Acoustoelectric Effect which he discovered and named, only to find that someone else had apparently done the same thing earlier. (It is characteristic of Gabi to work something out from the beginning before going to the library.) He was very discouraged, and retreated to his laboratory for a few days, doing some therapeutic glassblowing, before going to the library to read the earlier paper. He found that, in fact, it missed most of the crucial physics, now described by the so-called “Weinreich relation.” In the summer of 1957, Gabi invited me to join him at Bell Labs to test the theory, and see what we might learn from experiment. He and Harry White, his technician, had already verified some of the predictions in a preliminary experiment. Harry learned to grow his own germanium crystals, I succeeded in getting an apparatus through Bell Labs’s shop, we learned how to operate a hydrogen liquefier, and we were taking data by the end of the summer. The result was some pretty physics which led both of us to some other interesting experiments.

University of Michigan

Gabi came to Michigan in 1960, I in 1963. He developed a graduate course in Solid State Physics, from which came his 1965 book Solids: Elementary theory for advanced students. He taught Physics 510 (then a course in Classical Thermodynamics, out of which came another book Fundamental Thermodynamics, in 1968. Since he and I had adjoining offices, with a connecting door, I was forced to learn a great deal during this period. His unconventional and original approach in the books has limited their adoption as textbooks in standard courses, but they continue to be cited in the literature by an enthusiastic, if too narrow, audience. He then undertook a complete overhaul of our General Physics courses for science and engineering students. The result, again, was very original but, like the Feynman Lectures, was not widely regarded as suitable for a standard course. He also developed a very successful course in the Physics of Music.

At Michigan, Gabi’s first research was as part of the “Resonance Group”, which Peter Franken and Dick Sands has started earlier. He made a crucial contribution to the production of optical second harmonics by pointing to the necessity of using a material lacking inversion symmetry. His first Ph.D. students worked in areas of Solid State physics which grew out of his work at Bell Labs.

After some work in Atomic Physics, collaborating with Jens Zorn, he started his own work in Musical Acoustics. One of his first efforts was to try to understand why a piano has more than one string for each note. The result, showing why the piano’s transient is not a simple exponential decay, appeared both in the physics literature and in a cover article in Scientific American. One of his major accomplishments was to convince the National Science Foundation to support his work, in a field previously denied support as a matter of policy. He had to do a lot of convincing, at the end of which Senator William Proxmire singled out his grant for a “Golden Fleece” award. Gabi explained the value of his research to the Senator so convincingly that Proxmire was reduced to complaining that he wished the NSF officials had been nearly so persuasive. In his research on the violin, one of his important accomplishments was to show how the outgoing wave from a violin could be measured, even in the presence of incoming radiation. Such a measurement was possible since both the amplitude and phase of a vibration are accessible. Previous workers had generally relied on intensity data only. He also devised ingenious arguments, based on reciprocity, to relate vibration of the violin body to the radiated acoustic field. His recent violin research treated the physics of a bowed string and utilized a computer in a feedback loop, constituting what he calls a “Digital Bow.”

He has maintained a collaboration with acousticians at Pierre Boulez’s institute IRCAM (near the Pomipdou Centre), has supervised doctoral work at French universities, and was awarded the International Medal of the Société francaise d’acoustique in 1992. Within the last few years, he has been the Klopsteg lecturer of the American Association of Physics Teachers, and a Distinguished Public Lecturer (in Boston’s Symphony Hall) of the Acoustical Society of America. After the death of his friend Arthur Benade, Gabi served as the Acoustical Society’s editor for musical acoustics.

In addition to the research he has published in Solid State, Atomic Physics, and Musical Acoustics, he and I have co-authored several papers. Most of this research had the form of my posing a question and Gabi answering it.


It would not be right for me to omit a part of Gabi’s life which has been of great importance to him in recent years. Beginning approximately twenty years ago, he became increasingly interested in religion. His study of scripture required him to read Hebrew, another of the languages he does not know and Greek. He followed a complicated trajectory to ordination as a priest in the Episcopal Church in 1986, to service as an Assistant Rector at a church in Ann Arbor, finally (in phased retirement) to become half-time Rector of St. Stephen’s parish in Hamburg. It is an activity from which he clearly derives a great deal of satisfaction, and through which he accomplishes good in the community.

He and I, of course, discuss religious matters a good deal over coffee. He applies the same startling originality and intelligence to these activities as he does to his physics.

Bill Williams — memoir

William Lee Williams   (1937-1986)

Bill Williams, professor of physics and associate dean for Research in LS&A, was at the peak of his career as scientist and administrator when he died at the age of 49 in the aftermath of an airplane accident on 11 November, 1986.

He received his undergraduate education at Rice University (1959), his M.S. at Dartmouth College (1961), and his Ph.D. from Yale(1965). Bill, whose dissertation research on the isotropy of gravitational mass has been recognized by a prize from the Gravity Foundation, joined the Michigan faculty in 1965.

His academic career was spent at The University of Michigan, where he arrived as an instructor in 1965. He advanced to assistant professor in 1966, associate professor in 1969, and professor in 1976. He was also guest professor at Heidelberg in 1972-1973, as a Humboldt Foundation senior fellow. He served as associate chairman of the Physics Department, and was, from 1985 until the time of his death, the associate dean for Research in the College of Literature, Science, and the Arts.

Bill Williams, 1968

At Michigan he started an ambitious series of experiments to measure the fundamental properties of atomic hydrogen and helium, experiments that culminated in a major undertaking to measure the effects of parity violation in atomic hydrogen. He had also done astrophysical research on the polarization of light from white dwarf stars, and he was just starting a new collaboration in a particle physics experiment.His published work included 27 papers and 9 invited addresses at conferences. His “Doktorfamilie” contained 11 students, and he influenced a large number of students in his teaching career.

He had a wide range of interest outside of physics. As a person with an understanding of history and a strong sense of fairness, he spoke clearly on social justice and on arms control. As an eclectic musician he played chamber music and had a fondness for opera that led him to learn Italian; he also played folk guitar, notably as lead in an old-time gospel quartet, with an authenticity derived from his childhood years in Oklahoma. As an athlete he was known for his ferocious game of squash and for his skill as a sailor. As an aviator and enthusiastic leader in the Michigan Flyers, Bill was generous in sharing his love of the sky with countless others.

Above all, Bill had a remarkable talent for warm relationships with people. To work with him was to be drawn into a circle of friendship that included distinguished professors, younger faculty colleagues, graduate students, instrument makers, secretaries, pilots, and many others. We are fortunate to have had him on our faculty for 21 of his 49 years.