The History of the

Department of Physics and Astronomy

Tufts University

William Oliver

February 2007

A noted early member of the Department was Amos Dolbear. Dolbear constructed a telephone in 1865, eleven years before Alexander Graham Bell patented his model. In a dispute with Bell that went to the U.S. Supreme Court, Dolbear was unable to satisfy patent office formalities so did not receive credit as the inventor of the telephone. Dolbear came to Tufts in 1874 as Chair of the Physics Department. While at Tufts he invented a wireless telegraph system with a range of more than a quarter mile, and succeeded in obtaining a U.S. patent for his system. The Marconi Company was required to purchase Dolbear’s patent before it could operate any wireless systems in the U.S.

Prior to the arrival in 1955 of Julian Knipp, the Department engaged primarily in undergraduate teaching with some research in experimental physics. Prof. Knipp was hired by the Tufts administration as Chair and given the charge of expanding the research scope of the Department. Knipp instituted a Ph.D. program and decided to concentrate research in the areas of condensed matter physics and elementary particle physics. At this time the Department shared a single building, Robinson Hall, with the College of Engineering.  Including its basement and attic, Robinson Hall provides 20,000 square feet of classroom, office, shop, and laboratory space.

Research in condensed matter physics was being pursued at Tufts by Prof. Kathryn McCarthy, who was measuring the low-temperature thermal conductivity of crystalline materials and the attenuation of ultrasonic waves in superconducting niobium in her labs in the basement of Robinson Hall.  Knipp augmented this research by hiring Howard Sample and Leon Gunther. Prof. Sample specialized in low-temperature thermal properties of materials, and instituted a program of measuring the effects of magnetic fields on thermometers at low temperatures. Sample conducted his experiments at the Francis Bitter National Magnet Laboratory at MIT.  Prof. Gunther, in collaboration with Yosef Imry (Weizmann Institute), studied various systems in one and two dimensions, a field of research at that time not experimentally realizable.  In particular, Gunther and Imry showed that the “Bloch oscillations” of the electric current in a superconducting ring (dependent on the magnetic flux through the ring) are exhibited also by a free electron gas in the ring. In both cases the current is persistent and is a characteristic of the equilibrium state. The phenomenon was first believed to occur only in superconducting rings, but later experimentation showed that the phenomenon also occurs at very low temperatures in metal rings with normal electrical resistance. This result was one of several instances in which Gunther and his collaborators demonstrated that theoretical proofs prohibiting stability of certain correlated states in low-dimensional samples (such as superconductivity and the simple harmonic lattice) are not applicable to real samples because of the necessarily finite size of a real sample.

Knipp launched the experimental research program in particle physics by hiring Jacob Schneps in 1956. In 1957, Knipp and Schneps were awarded a grant of $22k by the Atomic Energy Commission for experimental and theoretical research in particle physics. The Tufts particle physics group has succeeded in obtaining a renewal of this grant (first by the AEC, then by its successor agencies - the Energy Research and Development Administration and the Department of Energy) every year for the past fifty years.

In 1961 the Department became the sole occupant of Robinson Hall as the College of Engineering moved to the newly constructed Anderson Hall. By 1964 the particle physics faculty had grown to seven members, including theorists Allen Everett and David Weaver, with total AEC funding at an annual rate of $260k. Notable among the new members was Allan Cormack, a nuclear physicist who had conceived the idea of the CT scanner in 1956 in Cape Town, South Africa.  After joining the Tufts faculty in 1957, Cormack worked principally on experiments in nuclear physics at the Harvard cyclotron. However he continued to work on the scanner, developing the mathematical methods necessary to reconstruct an image, and demonstrating the feasibility of his idea using a gamma ray beam to scan a plastic cylinder in which an off-axis aluminum cylinder had been embedded. In 1979 Professor Cormack received the Nobel Prize in Medicine for his work on the CT scanner.

During the 1950s and 1960s Professor Schneps worked with nuclear emulsions, exposing the emulsions to K^- mesons produced at the Bevatron at the University of California at Berkeley. Schneps determined the properties of the sigma hyperons, hypernuclei, and the resonant nuclear states formed in the capture of the K^- mesons by the emulsion nuclei. The tracks in these events were measured using microscopes set up in the attic of Robinson Hall. Another highlight of this period was the invention of the backscattered laser beam by Professor Richard Milburn. A laser beam backscattered by a high energy electron beam becomes a gamma ray beam retaining the polarization of the original photon beam.  Milburn developed the required laser system in his lab in the basement of Robinson Hall, and transported his system to the Cambridge Electron Accelerator at Harvard where he verified the production of gamma rays using an array of lead glass blocks.

The expansion of the research program resulted in 1967 in a division of the Department.  The experimental particle physics group moved to Bacon Hall, a 9,000 square-foot building located half a block from Robinson Hall.  The group had by now informally divided itself into two subgroups: one primarily using bubble chamber techniques, the other using spark chamber and counter techniques. The bubble chamber group set up six machines in Bacon Hall to scan and measure events recorded in film exposed in experiments conducted at the Brookhaven National Laboratory and the Rutherford High Energy Laboratory. The counter group developed, under the leadership of Assistant Professor John Rutherfoord, a system of 80 lead glass blocks with associated photomultiplier tubes, light flashers, and radioactive sources.  The system, together with a PDP-11 computer to control its operation, was taken to the Cornell Electron Synchrotron where a measurement of wide-angle Compton scattering was performed. Rutherfoord is now a Professor of Physics at the University of Arizona.

In 1968 Prof. Cormack became Chair as Knipp was promoted to become the Dean of the College of Liberal Arts. That year Robert Guertin was added to the experimental condensed matter research program. Prof. Guertin performed his research at the Francis Bitter Laboratory, measuring the properties of materials containing low concentrations of magnetic impurities under extreme conditions of high magnetic field and high pressure. Research in particle theory evolved with the addition of Gary Goldstein, a specialist in high energy scattering phenomenology, particle symmetries, and the effects of spin in strong interactions. Prof. Goldstein soon began a long-term collaboration with Prof. Michael Moravcsik (Oregon) to study spin amplitudes as measurable in polarization experiments. Goldstein also worked with Prof. Richard Dalitz (Oxford) to develop measures of heavy flavor quark spin polarization in hadron jets. Goldstein and Dalitz went on to consider the production and decay properties of the top quark and developed a method for detecting the top quark and determining its mass in proton-antiproton collisions at the Fermilab Tevatron. Work in experimental particle physics also evolved as W. Anthony Mann in 1974, and William Oliver in 1976, joined the Department.  Prof. Mann came to Tufts with experience in neutrino experiments, and Prof. Oliver brought his experience with counter and multiwire proportional chamber techniques.

Astronomy had been taught at Tufts as early as the time of Amos Dolbear, who is identified as a professor of physics and astronomy on his portrait which hangs in Robinson Hall. Before the arrival of George Mumford in 1955, there had been no astronomy courses offered at Tufts for some time. Prof. Mumford had a Ph. D. in observational astronomy, but since Tufts had no Department of Astronomy, he became a member of the Department of Mathematics. Immediately on his arrival, Mumford developed several astronomy courses which he taught until 1969, when he became Dean of the College of Liberal Arts. Paul Blanchard, also a member of the Department of Mathematics, taught the astronomy courses from 1968 until he left Tufts in 1974.

In 1974 Kenneth Lang was hired as an Assistant Professor of Astronomy in the Department of Physics to perform research in astronomy and to teach the astronomy courses. His investigations of the Sun using ground-based radio telescopes and X-ray and ultraviolet telescopes aboard satellites have been funded by NASA for three decades. In 1987 Mumford stepped down as Dean of the Graduate School to resume teaching in astronomy, but now as a member of the Department under its new name - the Department of Physics and Astronomy. Lang and Mumford shared the teaching duties in astronomy until Mumford’s retirement in 1997. Since 1997 Lang has been assisted in meeting the high student demand for astronomy courses by Research Professors Robert Willson and William Waller, Visiting Professor Rosanne DiStefano, and Lecturer Esther Zirbel.

Prof. Weaver moved from particle theory to biophysics theory in 1972, aided by a leave spent working with Martin Karplus in the Chemistry Department at Harvard.  The mechanism by which polypeptide chains fold to their unique native state was then a key unsolved problem in biology. Weaver and Karplus developed what came to be known as the diffusion-collision model of protein folding. With the simplifications provided by the model, folding rates could be related to physical parameters for the first time. Weaver received grants from NASA, NATO, and the NIH to establish the computer facilities at Tufts necessary to determine the folding trajectories. The diffusion-collision model was ahead of its time because the data needed to test it were not available when it was published in 1976.  But by the mid-1990s experimental studies had shown the model does indeed describe the folding mechanism of many simple proteins.

Prof. Everett replaced Prof. Cormack as Chair in 1976. Over the next few years the theoretical research program was broadened by the hiring of Alexander Vilenkin and Lawrence Ford. Vilenkin and Ford are experts in quantum field theory and general relativity. The experimental particle physics group was strengthened by the hiring of Austin Napier, who brought experience in both bubble chamber techniques and in counter techniques. 

Prof. Schneps became Chair in 1980. Schneps had the foresight to establish the John F. Burlingame Graduate Fellowship in Physics to support the research work of our most outstanding graduate students. John Burlingame graduated from Tufts in 1943 with a major in physics.  After three years of service in the U.S. Navy, he joined General Electric as an engineer in military electronics. In 1968 Burlingame moved into management at GE and eventually rose to Vice Chairman, the position he held when he retired in 1985. For several years beginning in 1984, Burlingame (with matching contributions from GE and Hershey) donated the money to endow the fellowship. The endowment had grown to $78k in 1989 when the first Burlingame Fellowship of $3.5k was awarded, providing partial support for a single graduate student. The Burlingame Fund has now grown to $1M, enabling it to provide full-time support to two or three graduate students each year.

In the early 1980s, members of the Tufts particle group (Mann, Milburn, Napier, Schneps) participated in a bubble chamber experiment at SLAC that utilized the backscattered laser beam technique (pioneered by Milburn in the 1960s) to perform the first definitive measurements of the lifetimes of charmed mesons.  These measurements showed that the charmed quark decays independently of the flavor of the other quark within the meson.

In the 1980s Vilenkin, Ford, and Everett began to make important contributions to cosmology theory. The consequences of topological defects formed in phase transitions in the early universe were investigated by Vilenkin and Everett. In particular, Vilenkin proposed a model in which cosmic strings act as the seeds for the initial density perturbations which produce galaxies. Several key aspects of the inflationary cosmology paradigm were developed by the Tufts group. Vilenkin proposed the concept of eternal inflation – that once inflation begins, it must always continue somewhere in the universe. Eternal inflation leads to the idea of a “multiverse” which has recently become central to string theory. Vilenkin and Ford calculated the quantum fluctuations of a minimally coupled scalar field in deSitter space and found a growth in the fluctuations which is important in inflationary models. Ford proposed a model for reheating the universe at the end of inflation which relies only upon quantum creation of particles by the gravitational field.

Recognizing the growing strength of cosmology research within the Department, Schneps in 1989 led the establishment of the Tufts Institute of Cosmology, at that time the only research center in the U.S. devoted to theoretical cosmology.  Schneps obtained the Institute’s initial endowment of $450k from a donation to Tufts in 1961 by the Gravity Research Foundation established by Roger Babson. Vilenkin has served as Director of the Institute of Cosmology since its inception. The Institute has hosted numerous postdoctoral and senior researchers from around the world. A joint cosmology seminar was established, originally rotating between Tufts and Harvard, and later including MIT.

In 1984 the experimental particle physics group joined the Soudan2 collaboration in proposing a 1000-ton calorimeter to serve as a proton decay detector to be installed in the Soudan mine in northern Minnesota. Tufts took on the responsibility of designing and constructing the veto shield – the detectors to be mounted on the cavern walls to identify incoming muons which, if undetected, would create background to the search for proton decay events within the calorimeter. The construction of the veto shield was a project on a scale never before attempted by Tufts, and the group united to meet the challenge.  The shield detectors and electronic readout system were designed by Oliver, and the factory in Bacon Hall to construct the detectors was designed and managed by Mann. The factory occupied only 2200 square feet, yet the group was able to construct 1400 detector modules (most with a length of 29 ft) with a total mass of 54 tons over the course of five years beginning in 1986. A moving van was used to ship the completed modules to Minnesota in batches of roughly 100. Members of the Tufts group met the van on its arrival at the Soudan mine and supervised the mounting of the modules on the cavern walls. The Soudan2 experiment recorded data continuously from 1989 to 2001. Under the leadership of Prof. Mann, who served as the spokesperson from 1996 until the final Soudan2 publication in 2005, Tufts doctoral students led investigations which set the current best limits on certain proton decay modes and on neutron-antineutron oscillations. Prof. Mann also led the analysis of the interactions of neutrinos that are produced in the upper atmosphere by cosmic rays incident on the earth.  Soudan2 is recognized as one of the two experiments to confirm the discovery of neutrino oscillations by the Superkamiokande experiment using a distinctly different detector technology.

Yaacov Shapira, a Senior Research Scientist at MIT with a distinguished record of research at the Francis Bitter National Magnet Laboratory, joined the Department as Professor in 1987. In 1984 Shapira and his coworkers invented the technique of magnetization steps that has proven to be useful in obtaining information on magnetic systems quite difficult to obtain otherwise.  At Tufts, Prof. Shapira did extensive work on the electrical transport properties of diluted magnetic semiconductors.

In his final year as Chair, Schneps hired Krzysztof Sliwa to join the experimental particle physics group.  Prof. Sliwa came to Tufts from Fermilab, where he was a member of the CDF experiment measuring the final states produced by proton-antiproton interactions at the Tevatron Collider.  The hiring of Sliwa brought Tufts as an institution into the CDF collaboration.  The CDF experiment continues to the present, with Sliwa and Napier now active in this effort. Prof. Sliwa has worked principally on the determination of the mass of the top quark from the measurements made in the CDF detector of events in which one or two leptons with accompanying hadron jets have been identified. The analysis technique originated by Prof. Goldstein and Prof. Dalitz (Oxford) for the determination of the top quark mass in events in which two leptons are identified was extended by Sliwa, Goldstein, and Dalitz to apply to single lepton events.

Prof. Weaver became Chair in 1990. The continued growth of the research program forced a further expansion of the Department in 1991. Funded in part by a $10M grant from the U.S. Department of Energy, Tufts renovated a building formerly occupied by the Acme Printing Company to form the Tufts Science and Technology Center.  Prof. Guertin was instrumental in developing office and lab space within the STC for all the members of the Department performing experimental research. The particle physics group vacated Bacon Hall to occupy 4400 square feet on the first floor of the STC, while the condensed matter group moved from Robinson Hall to occupy 4600 square feet on the second floor. The two groups share, along with the other science departments in the STC, a 7700 square-foot machine shop equipped with modern machine tools, including a large (30-in by 60-in travel) 3-axis computer-controlled milling machine.

In the early 1990s the Department had 19 regular faculty members. All the regular faculty members had received tenure, and 17 had reached the rank of full professor. Guertin was serving as the Dean of the Graduate School, but the remaining 18 were active in teaching and research. Five faculty members were lost in the mid 1990s with the death of Sample, and the retirements of Cormack, McCarthy, Milburn, and Mumford. These losses were compensated in part by the hiring of Peggy Cebe in 1995 and Roger Tobin in 1996 as Associate Professors from similar positions at MIT and Michigan State. Cebe and Tobin were experienced researchers in condensed matter physics who were able to transfer their equipment to labs in the STC and immediately resume their research programs.  Prof. Cebe works principally on measurements of the effects of phase structure on the properties of polymers.  Prof. Tobin studies the interaction of atoms and small molecules with the surfaces of metals; his optical and electron spectroscopy measurements must be performed under ultrahigh vacuum conditions.

The Department has provided undergraduate and graduate instruction in physics since 1955, and provided undergraduate instruction in astronomy since 1974. We teach large-enrollment introductory physics courses primarily to an audience of engineers and premedical students, intermediate undergraduate physics courses to science majors and engineers, introductory astronomy and interdisciplinary courses to an audience of non-science students, intermediate undergraduate courses in astronomy to engineers and science majors, and the graduate courses necessary for Ph. D. students. Our ability to teach the full breadth of this curriculum was diminished by the loss of faculty members during the 1990s.  By 1998 our regular faculty had been reduced to 16, even given the return to teaching and research of Prof. Guertin. The regular faculty has remained at the level of 16 to the present. With the reduction in faculty, four of our intermediate undergraduate physics courses are offered every other year, rather than every year as formerly. We are able to maintain the breadth of our astronomy offerings through the use of research professors and lecturers.

The STC shop provides essential support for the experimental groups. Shop technicians Denis Dupuis, Scott Maccorkle, and Larry McMaster have many years of experience designing and building scientific equipment. Prof. Cebe makes regular use of the shop in her ongoing research program which utilizes the National Synchrotron Light Source at Brookhaven National Laboratory to analyze the materials she creates. The shop technicians help design the mechanisms that hold (and provide temperature regulation for) the samples during exposure to the synchrotron light. In many cases the technicians proceed to manufacture the apparatus without the need for detailed drawings. Prof. Tobin relies on the shop for crucial work necessary to maintain his ultrahigh vacuum apparatus.

The particle physics group utilized the large area available in the STC shop in its role in the Fermilab DONUT experiment that succeeded in making the first observations of tau neutrino interactions. In 1994-95 the group built an array of proportional tubes that formed the muon identifier of the DONUT experiment. The design of the identifier required the tubes to be assembled into 12-ft high walls; several trial walls were built in the STC shop before a stable design for the assembly was achieved. The Tufts group used its experience to supervise the subsequent construction of the muon identifier at Fermilab. In 1999-2002 the particle physics group used the shop to construct components for the MINOS long-baseline neutrino oscillation experiment. The group machined 1000 each of three components of the scintillator modules, and assembled 225 optical multiplexing boxes. The STC shop was also used extensively to fabricate components for the factory in which the detectors used in the endcap region of the ATLAS detector at the Large Hadron Collider were manufactured.

Research in theoretical cosmology continued during the 1990s.  Prof. Vilenkin developed a probabilistic method for making predictions in multiverse models; he used his method to sharpen Weinberg’s prediction of a nonzero cosmological constant.  Ken Olum, a research faculty member who joined the Institute of Cosmology in 1997, resolved some long-standing problems in the dynamics of cosmic strings and studied possible mechanisms of high-energy cosmic ray production by topological defects.  Prof. Ford developed inequalities constraining quantum effects which could create negative energy densities. The inequalities help to explain how the laws of physics prevent such exotic phenomena as faster-than-light travel or time travel.

In 2000 Prof. Goldstein began to work part-time on science education as a subcontractor for an NSF-TPC grant to TERC, a not-for-profit educational research organization founded in 1965. Goldstein works with the faculty of the King-Open School (K-8) in Cambridge to improve the learning of formal science through full utilization of the prior experiences of the students.  In 2003 the Department moved more broadly into science education research through the work of Goldstein, Tobin, Waller, and Zirbel with the Fulcrum Institute. The Fulcrum Institute (funded by an NSF-MSP grant) is working to develop an on-line interactive Masters program in science education.

Prof. Oliver became Chair in 2002.  The experimental particle physics group was augmented in 2004 by the hiring of Hugh Gallagher as an Assistant Professor. Prof. Gallagher is an expert in neutrino-nucleus interactions; his arrival enhanced the ability of the Tufts group to contribute significantly to the analysis of the neutrino-oscillation data now being taken by the MINOS experiment.

The research program in cosmology was slowed by the retirement of Prof. Everett in 2004, but the Institute of Cosmology was soon restored to its former strength by the hiring of Jose Blanco-Pillado as an Assistant Professor in 2006.  Prof. Blanco-Pillado is an expert on the relation of string theory to cosmic inflation, having shown that his concept of racetrack inflation is the most economical mechanism for the realization of inflation within string theory.

The sudden death of Prof. Weaver in 2006 has resulted in a termination for now of our research program in theoretical biophysics.

The decline in the number of regular faculty members over the past 13 years was reversed by the Tufts administration in 2006. The Department has a search in progress for an Assistant Professor in observational astronomy.  This second tenure-track position in astronomy should stabilize our undergraduate major program in astrophysics.