University of Cambridge

Interview with Mark Trodden, Fay R. and Eugene L. Langberg Professor of Physics, and Co-Director of the Center for Particle Cosmology at the University of Pennsylvania. Trodden describes the overlap between astronomy, astrophysics, and cosmology, and he recounts his working-class upbringing in England. He discusses his undergraduate education at Cambridge, where he focused on mathematics, and he explains his decision to switch to physics for graduate school at Brown, where he worked under the direction of Robert Brandenberger. Trodden describes the impact of the COBE program during this time, and he discusses his work on the microphysics of cosmic strings and topological defects and their effect on baryon asymmetry. He explains his decision to return to Cambridge for his postdoctoral research with Anne Davis and his subsequent postdoctoral appointment at MIT to work with Alan Guth. Trodden discusses his next postdoctoral position at Case Western, which he describes as a tremendously productive period, and he discusses the opportunities that led to his first faculty position at Syracuse. He notes the excellent graduate students he worked with at Syracuse, and he explains what is known and not known with regard to the discovery of the accelerating universe. Trodden describes why the theory of cosmic inflation remains outside the bounds of experimental verification, and he explains the decisions that led to his decision to join the faculty at Penn and his subsequent appointment as chair of the department. He discusses the work that Penn Physics, and STEM in general, needs to do to make diversity and inclusivity more of a top-line agenda, and he describes much of the exciting work his current and former graduate students are involved in. At the end of the interview, Trodden looks to the future and offers ideas on how physicists may ultimately come to understand dark energy and dark matter.

Interview with Peter Lepage, Tisch Family Distinguished University Professor of Physics at Cornell. He recounts his childhood in Montreal and his decision to pursue an undergraduate degree in physics at McGill. Lepage discusses his Master’s work at Cambridge University and his decision to do his thesis research in particle physics at Stanford. He describes the fundamental advances happening at SLAC during his graduate years and his work on bound states of electrons and muons under the direction of Stanley Brodsky. Lepage discusses his postdoctoral appointment at Cornell and his work in high-precision QED calculations in atoms, and he describes the foundational impact of Ken Wilson’s work on lattice QCD and the intellectual revolution of renormalization. He describes this period as his entrée into QCD research, and he emphasizes the beauty of Ithaca and the supportive culture of the Physics Department as his main reasons to accept a faculty position at Cornell. Lepage explains how and when computers became central to Lattice QCD research and why effective field theory was an area of specialization that was broadly useful in other subfields. He describes the ongoing stubbornness of the Standard Model, and he discusses his tenure as chair of the department, then as Dean of the College of Arts and Sciences, and his work on PCAST in the Obama administration. Lepage explains his longstanding interest in physics pedagogy, and he discusses his current work on the numerical integration program called VEGAS. In the last part of the interview, Lepage emphasizes that the most fundamental advances in physics are in astrophysics and cosmology and that lattice QCD should be “kept alive” because it’s unclear where it is going until physics goes beyond the Standard Model.

Interview with Robert H. Brandenberger, Canada Research Chair and professor of physics at McGill University. Brandenberger recounts his childhood in Switzerland as the son of organic chemists, and he describes his undergraduate education at the ETH Zurich in physics. He discusses his graduate research at Harvard to work under the direction of Arthur Jaffe, and he describes his first exposure to cosmic inflation. Brandenberger describes his postdoctoral appointment at the ITP in Santa Barbara where he worked with Neil Turok and Andreas Albrecht, and his subsequent postdoctoral work with Stephen Hawking at Cambridge. He explains his initial ideas on cosmic strings as an alternative to inflation and his encounters with Cumrun Vafa and Slava Mukhanov. Brandenberger describes the origins of string gas cosmology, its implications for a multiverse and how it was received among string theorists. He discusses his faculty appointment at Brown and he explains his decision to move to McGill where the opportunity to work with graduate students was stronger. Brandenberger surmises what string theory as a testable proposition would look like, and he reflects on some of the obvious philosophical implications of unknowability in the universe. He explains the difference between a toy model and a proper theory, and he conveys optimism that string gas cosmology will advance research on dark energy. At the end of the interview, Brandenberger reflects on the idea that string theory is "smarter than we are."

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.

Interview with John Ellis, Clerk Maxwell Professor of Theoretical Physics at King’s College London, and Visiting Scientist at CERN. Ellis discusses the g-2 experiment at Fermilab and where he sees current efforts geared toward understanding physics within the Standard Model, and pursuing new physics beyond it. He recounts his childhood in a small town north of London and his innate interest in physics before he understood that it was a proper field of study. Ellis discusses his education at Cambridge and the department’s strength in particle physics, general relativity, and cosmology, and he explains the relevance of the deep inelastic scattering research at SLAC for his thesis on approximate symmetries of hadrons. He describes the intellectual influence of Bruno Zumino and his decision to go to SLAC for his postdoctoral research to work on scale invariance. Ellis discusses his subsequent research at Caltech and he explains why he would have appreciated more the significance of asymptotic freedom had he better understood field theory at that point. He discusses his subsequent position at CERN and is collaboration with Mary Gaillard on semileptonic decays of charm. Ellis narrates the famous “penguin diagram” that he developed with Melissa Franklin and his interest in grand unification and how it differs from the so-called “theory of everything.” He describes the optimism in the 1980s that supersymmetry would be found and its possible utility in the search for dark matter. Ellis discusses his involvement with LEP and axion physics, and he reflects on the spirit of competition and collaboration between ATLAS and CMS in the run up to the Higgs discovery. He explains the new questions that became feasible as a result of the discovery and his interests in both gravitational waves and supernovae. Ellis describes the AION experiment, the important physics research currently in the works in China, and key recent developments in quantum gravity. At the end of the interview, Ellis conveys his belief in the importance of science communication, he minimizes the importance of the h-index as a measure of excellence, and in reflecting on his own career, he cautions against younger physicists becoming overly-specialized. 

Interview with Hiranya Peiris, Professor of Astrophysics at University College London and Director of the Oscar Klein Centre and Professor of Cosmo-Particle Physics at Stockholm University. Peiris describes her dual affiliation, she discusses diversity in STEM over the past year, and she surveys the current interplay between theory and observation in her field. She recounts her childhood and family heritage in Sri Lanka and the circumstances that led her family to relocate to the United Kingdom. Peiris describes her interests in math and science the opportunities that led to her enrollment at Cambridge as an undergraduate and a formative experience at JPL in California. She explains her decision to pursue a PhD at Princeton, where she worked with David Spergel on WMAP. Peiris discusses her postdoctoral appointment as a Hubble fellow at the University of Chicago to continue to work on WMAP, and her subsequent work as a Halliday fellow at Cambridge. Peiris discusses her work on the Lyman-alpha forest and her faculty appointment at UCL where cosmology was just coming into maturity. She conveys the excitement as WMAP results were becoming available and her contributions to the search for dark matter. Peiris explains why the LSST project is so significant, what it was like to win the Breakthrough Prize, and the gratitude she feels by having eminent physicists as mentors. At the end of the interview, Peiris emphasizes the importance of following inquiry into the most fundamental questions surrounding gravity and space time, and why Stephen Hawking remains an intellectual inspiration to her.

Interview with Alan Dressler, Astronomer Emeritus at The Carnegie Institute for Science Observatories. He describes his current focus on the James Webb Telescope and he conveys concern for a "post-reality" political environment that has taken a grip on American politics. He recounts his upbringing in Cincinnati, and how his curiosity about how things worked naturally pulled him toward astronomical interests. Dressler discusses his undergraduate education at UC Berkeley and his decision to pursue a PhD in the newly created Department of Astronomy at UC Santa Cruz. He describes the importance of the Lick Observatory for his research under the direction of Joe Wampler, and how Jim Peebles gave this thesis project a "seal" of approval. Dressler describes the origins of the Dressler Relation in his study of the morphology of galaxies and the density of their environment, and he describes the opportunities leading to his postdoctoral appointment at Carnegie. He explains the history of the Caltech-Carnegie partnership in astronomy, and he describes working with Allan Sandage and Jim Gunn. Dressler emphasizes the revolutionary effect the Hubble Telescope imparted to the field, and he discusses his time as a Las Campanas fellow. He describes how his work on galaxy formation fed into larger questions about the origins of the universe and the broader philosophical implication of our understanding of Earth's place in the universe. Dressler explains the Great Attractor Model and the state of play in black hole research in the 1980s, and he describes why he did not need to "see" an image of black holes to be convinced of their existence. He narrates the origins of the Association of Universities for Research and Astronomy, and the drama surrounding the repair of the Hubble. Dressler describes presenting the HST & Beyond report to NASA administrator Dan Goldin, and he discusses the natural progression for his work on the NASA Origins program. He discusses his subsequent focus on the Magellan Telescope and the EOS Decadal Survey. At the end of the interview, Dressler reflects on the strides made in galaxy formation research over the course of his career, and he conveys pride in playing a role in science, for which he appreciated since youth as a field that offered limitless opportunities to improve the world. 

Interview with Roger Blandford, the Luke Blossom Professor at the School of Humanities and Sciences at Stanford University and Professor of Physics at SLAC. He discusses his current work developing alternate understandings of the Event Horizon Telescope image, on fast radio bursts, and on the notion that handedness has astrophysical origins. Blandford describes the history of cosmology as a respectable discipline within physics, and he credits the rise of VLBI in the 1960s and 1970s for demonstrating the evidence of black holes. He recounts his childhood in England, his early interests in science, and his education at Cambridge, where his thesis research on accretion discs and radio sources was supervised by Martin Rees. Blandford discusses his postdoctoral work on astrophysical particle acceleration and plasma and QED processes in pulsars and a formative visit to the Institute for Advanced Study and to Berkeley. He describes his initial impressions of Caltech where he joined the faculty and where he worked closely with Roman Znajek, and he explains the distinctions between radio jets and relativistic jets. Blandford explains his reasons for moving to Stanford to set up the Kavli Institute and he describes his involvement with the Astronomy and Astrophysics Decadal Survey. At the end of the interview, Blandford contends that the most exciting developments in the field have been on exoplanet research, why the possibilities in astrobiology give him cause for optimism, and why the concept that astronomical discovery arrives as “logically unscripted” resonates with him.

In this interview, David Zierler, Oral Historian for AIP, interviews William Eaton, NIH Distinguished Investigator and Chief of the Laboratory of Chemical Physics. Eaton recounts his childhood in Philadelphia and he describes his undergraduate and graduate work at the University of Pennsylvania, where he earned an M.D. a Ph.D. He describes his budding interests in chemical physics during his time in medical school and his formative research at Cambridge, where he worked on protein synthesis. He conveys the serendipity surrounding his decision to join the NIH as a result of his experience with the draft during the Vietnam War. He discusses his offer to head the biophysics program at Harvard, and he explains his decision to remain at NIH. Eaton provides a history of NMR and AIDS research at the NIH, and he describes his research agenda at the NIH, including his seminal work on sickle cell disease and protein folding. At the end of the interview, Eaton reflects on the value of his medical degree over the course of his career.

In this interview, David Zierler, Oral Historian for AIP, interviews Richard Leapman, Senior Investigator in the National Institute for Biomedical Imaging and Bioengineering and Scientific Director of the intramural program. Leapman recounts his childhood in England and he describes his early and formative experience playing with an optical microscope. He describes his undergraduate work at Peterhouse College of Cambridge University and the influence of Aaron Klug in his physics education. Leapman explains his decision to remain at Cambridge for his Ph.D., and he describes his work in the Cavendish Laboratory and Klug's suggestion that he focus on inelastic scattering of electrons in electron microscopes to perform elemental microanalysis. He discusses his postdoctoral work at Oxford and the opportunity leading to his research at Cornell in the School of Applied Engineering Physics. Leapman explains his attraction to join the NIH upon learning that he would have access to an electron microscope and could work on electron energy-loss spectroscopy. He describes some of the biological implications of this work, including the ability to look at cells to detect elemental distributions inside subcellular organelles. Leapman discusses his many collaborations across the Institutes at the NIH and the development of NMR spectroscopy, and he describes the partnership between NIH and NIST that ensured his access to cutting-edge technology over the course of his career. He describes various aspects of his research that have direct clinical value to treating a variety of ailments, including asbestos exposure to coronavirus. Leapman describes his work at the chief of electron beam imaging and micro-spectroscopy and the numerous collaborations he has pursued beyond the NIH at both National Labs and university labs. He discusses some recent advances in his field, including new abilities to determine the 3D structure of proteins, and he explains his administrative duties as Scientific Director of the Institute. At the end of the interview, Leapman describes how the study of electrons has connected all of his research, and he discusses some of the challenges and opportunities he has confronted in his career as a physicist operating in a biologically-focused research environment.