Aspen Center for Physics

In this interview, David Zierler, Oral Historian for AIP, interviews Thomas Appelquist, Eugene Higgins Professor of Physics at Yale University. Appelquist recounts his upbringing in rural Iowa and then Indiana, where he attended Catholic high school. He describes his undergraduate experience at Illinois Benedictine College and explains his attraction to attend a small school for college. Appelquist discusses his decision to attend Cornell for his PhD, and recalls that, relative to others in his cohort who went to larger schools, he had the most catching up to do in quantum mechanics. He explains the development of his thesis topic under the direction of Don Yennie, which focused on aspects of renormalization theory using the Feynman parametric approach. Appelquist contextualizes some of the broader questions in quantum field theory and quantum electrodynamics at this time, and he describes the opportunities that led him to SLAC for his postdoctoral research. He describes his interests there as focused on theories of the weak interactions, and he describes his initial faculty appointment at Harvard where he joined the particle theory group led by Shelly Glashow and Sidney Coleman. Appelquist discusses his close collaboration with Helen Quinn on how to renormalize Yang-Mills theories, and he explains his decision to take a tenured position at Yale in consideration of the culture at Harvard, where the prospects of tenure were minimal. He describes the revolutionary discoveries of asymptotic freedom, QCD, and the “November Revolution” at SLAC and Brookhaven at the time. Appelquist describes his research and administrative activities to advance the particle theory group at Yale, and his overall efforts to improve the department as chair and in particular building up the condensed matter theory group. He discusses his tenure as Dean of the Graduate School and his long-term involvement with the Aspen Center. At the end of the interview, Appelquist describes his current interests in lattice gauge theory and explains why he expects that physics will see double beta decay in the next generation of experiments.

In this interview, Michael Turner discusses his life and career. topics include: Kavli Foundation; Kavli Institute for Cosmological Physics; Fred Kavli; Aspen Center for Physics; Rand Corporation; California Institute of Technology (Caltech); Robbie Vogt; Ed Stone; Barry Barish; SLAC National Accelerator Laboratory; B.J. Bjorken; University of Chicago; Dave Schramm; Kip Thorne; Fermi Institute / University of Chicago Institute for Nuclear Studies; Bob Wagoner; University of California, Santa Barbara; Larry Smarr; Dan Goldin; quarks-to-cosmos study; National Science Foundation; Rita Colwell; Advanced LIGO; Atacama Large Millimeter Array (ALMA); IceCube South Pole Neutrino Observatory; Department of Energy; Argonne National Laboratory; Paul Steinhardt.

In this interview, Elizabeth Simmons discusses: role as Executive Vice Chancellor (EVC) at UC San Diego; impact of COVID-19; current developments in the field that she finds exciting; family background and childhood; experiences as a woman in physics; M.Phil at Cambridge in Volker Heine’s group working on condensed matter theory; study of condensed matter theory at Harvard; Howard Georgi; work on models exploring electroweak symmetry breaking and quark masses; opinions on why SSC died and the impact on the field; collaboration with Cynthia Brossman on the Pathways K12 outreach project supporting girls’ involvement in STEM; research on the top quark; interest in supersymmetry and physics Beyond the Standard Model (BSM) using a Higgless model; papers with husband Sekhar Chivukula and others exploring the idea of a five-dimensional spacetime; leading Lyman Briggs College; MOOSE model; reaction to the discovery of the Higgs boson; post-Higgs work distinguishing which models can and can’t be consistent with the data; consulting work for the American Physical Society (APS) and the wider academic and scientific community on matters of equity, diversity, and inclusion (EDI); advocacy on behalf of the LGBTQ community; advisory work for the Center for High Energy Physics in China; collaborations at the Aspen Center for Physics to support EDI in the field; role creating career development workshops for women at the International Center for Theoretical Physics; work increasing EDI in curricula and faculty hiring; building cross-field collaboration at UCSD; collaboration with other EVCs in the UC system; current physics work on model building and how to get the most out of available data; and current work on graviton-graviton scattering. Toward the end of the interview, Simmons reflects on intersectionality and the value of diversity in science and discovery.

Interview with Joshua Frieman, head of the Particle Physics Division at Fermilab, and professor of astronomy and astrophysics at the Kavli Institute for Cosmological Physics at the University of Chicago. He recounts his childhood in Princeton as the son of a physicist and his decision to attend Stanford as an undergraduate, where his interests in cosmology developed. Frieman explains that his options for graduate research in cosmology were narrow and his reasons for going to the University of Washington to work with Jim Bardeen before moving to Chicago to be Michael Turner’s first graduate student. He discusses his interest in approaching cosmology from the perspective of particle theory and his thesis focus on curved space time within a cosmological context. Frieman describes his postdoctoral work at SLAC and his first position at Fermilab in the theory group that Dave Schramm had started. He discusses his work on the Sloan Digital Sky Survey and then the Dark Energy Survey. Frieman explains what might be needed to understand dark energy, he describes his appointment at Chicago, and he explains the origins of the Magellan Telescopes project. He discusses the value of the Aspen summer sessions and his involvement with P5, and explains the value of the 2010 Decadal Survey. At the end of the interview, Frieman surveys the current slate of project at Fermilab and emphasizes the value of incorporating cosmological perspectives to high-energy and particle physics. 

Interview with Michael Green, Lucasian Professor Emeritus at Cambridge University and visiting professor at Queen Mary University. He recounts his childhood in London as the child of secular Jewish parents who immigrated to London just before World War II. Green discusses his early interests in physics and the opportunities that led to his enrollment at Cambridge, and he conveys Geoff Chew’s influence with his ideas on S-matrix and bootstrap theory, which informed his thesis research on hadronic interactions. He narrates the founding ideas that led to string theory and how the work on dual models became transformed into string theory. Green describes his postdoctoral work at the Institute for Advanced Study and his interactions with Veneziano. He explains his decision to return to Cambridge and the importance of the CERN theory group for his research, and he narrates the origins of his collaborations with John Schwarz. Green connects string theory to the ideas that led to supergravity, and he explains why he does not like the term “revolution” in relation to advances in string theory to explain what was happening between 1981-1984. He explains the meaning of the pronoun “super” in relation to string theory, and he conveys his disappointment that supersymmetry has yet to be observed. Green describes the importance of AdS/CFT and his contributions to the origins of D-branes with Joe Polchinski. He discusses his increasing reliance on computers for understanding aspects of AdS/CFT correspondence. Green reflects on winning the Breakthrough Prize, and the supposed aspirational recognition on working to unify the forces which are not yet unified, and he discusses the generational de-coupling of string theory education from particle physics. He provides sociological perspective in response to the impatience that certain physicists have expressed regarding string theory. At the end of the interview, Green ponders the future relationship between string theory and quantum computing, and he describes the field as an intellectual adventure which makes it difficult to predict the significance of these changes.