In this interview, Saul Perlmutter, Professor of Physics at UC Berkeley and Staff Scientist and senior faculty member at Lawrence Berkeley National Laboratory, discusses his life and career. Perlmutter shares that his research has not been slowed down by the pandemic by happy coincidence that he is currently focused on remote data analysis, and he recounts his childhood in Philadelphia where he was educated in Quaker schools. He discusses his early fascination with quantum mechanics and his decision to go to Harvard for his undergraduate education, where he cemented his interests in experimental physics. Perlmutter explains his decision to go to Berkeley for graduate school, where he worked in Buford Price’s group before Richard Muller became his graduate advisor. He discusses his early awareness of the cosmic microwave background and how he became involved with robotic searches for supernovae. Perlmutter describes the importance of NASA’s BITNET program as a way to connect observatory data worldwide to the computer systems at Berkeley, and he explains the intellectual and observational connections between the inflation, expansion, and acceleration of the universe. He discusses his postdoctoral research at Berkeley, and the circumstances leading to him becoming leader of the supernova group and how the DOE became more involved in astrophysics funding. Perlmutter explains the group’s focus on deceleration and he conveys the difficulties in scheduling telescope time to demonstrate spectroscopy proof of type Ia supernovae. He describes the origins of the SNAP satellite project, some of the early theoretical discussions on the nature of dark energy, and when, finally, his group secured long-term support from the Lab. Perlmutter narrates his first interactions with Brian Schmidt and Adam Riess and he describes the batch technique that could predict the discovery of supernovae, which vastly improved the efficiency of scheduling time on large telescopes. He explains the role of dark matter in speeding up the universe’s expansion, and he narrates the celebration with his team when he won the Nobel Prize and how he has chosen the use the political platform that comes with this recognition. Perlmutter discusses his interest in studying climate change, and at the end of the interview, he conveys his excitement about future observational discovery in astrophysics and cosmology.
In this interview, Peter Nanos discusses: family background and childhood in New Hampshire; decision to study at the Naval Academy; fraternal culture at the Academy; experience as a Trident Scholar working with Ralph Goodwin; Ph.D. at Princeton as part of the Burke Program; working in Bob Dicke’s gravity group on the first large-scale measurement of the polarization of the microwave background; work on the timing of the crab nebula pulsar; thesis advisor Dave Wilkinson; getting feedback on his thesis pre-publication from Bob Wilson; working with Captain Al Skolnick on the Navy High Energy Laser Program to demonstrate the ability to down supersonic aircraft with the Mid-Infrared Chemical Laser (MIRACL); decision to stay with the Navy as an engineering duty officer (ED); various assignments as ED, including on the USS America; involvement in Operation El Dorado Canyon (1986 U.S. bombing of Libya); effects of Reagan’s increased military spending; power of nuclear deterrence in reducing worldwide war fatalities; work with and promotion to director of Naval Strategic Systems Programs (SSP); use of the first GPS; START Treaty; work with Naval Sea Systems Command (NAVSEA); Drell commission to determine safety of the Trident II D5 missile; creation of the National Nuclear Security Administration; director position at Los Alamos; response to reports of “lost” nuclear material; explanation of laboratory shut down; position as associate director at the Defense Threat Reduction Agency (DTRA); creation of R&D Enterprise at DTRA; investments in nuclear detection technology; experiences running exercises; work with the Applied Physics Lab at Johns Hopkins; and post-retirement consulting work. Toward the end of the interview, Nanos reflects on demanding technical excellence and on the value of his training and study of physics, “the liberal arts of STEM.”
In this interview, Andreas Albrecht, Distinguished Professor of Physics and Director of the Center for Quantum Mathematics and Physics (QMAP) at the University of California, Davis, discusses his life and career. Albrecht describes the growth of the department since his arrival, his affiliation with QMAP, and the broader effort to integrate more mathematicians into the field of cosmology. He recounts his childhood in Ithaca as the son of two PhD scientists and family sabbatical visits to Santa Cruz and to the Soviet Union. Albrecht describes his budding interests in physics in high school, his undergraduate experience at Cornell and his early exposure to the ideas of Robert Dicke and Alan Guth. He discusses his graduate work at Penn and the circumstances that led him to become Paul Steinhardt’s mentee in cosmology. Albrecht conveys all of the excitement surrounding inflationary cosmology in the early-mid 1980s and the opportunity that led to his postdoctoral appointment with Steve Weinberg’s group at the University of Texas where he became interested in cosmic strings. He describes his subsequent postdoctoral appointment at Los Alamos where he worked with Wojciech Zurek and where his carpools with Geoffrey West proved to be a formative intellectual experience. Albrecht explains his decision to accept a staff position at Fermilab and the contemporary advances in cosmic strings scaling and why primordial nucleosynthesis was uniquely data-oriented relative to other fields in cosmology. He describes his subsequent faculty position at Imperial College in London and he emphasizes the productive and tight-knit cosmology community across the UK. Albrecht conveys the importance of the cosmic microwave background (CMB) experiments and how his ideas of equilibrium cosmology had changed over time and where the term “Boltzman Brains” originated. He describes how UC Davis was rapidly growing and how the opportunity to build a cosmology group was appealing to him. Albrecht explains the origins of his “arrow of time” concept and why this resonates with the broader public’s interests in the universe. He conveys the existential difficulty, and possible impossibility, of developing a credible theory of the beginning of the universe. Albrecht reflects on the spiritual dimensions of cosmological unknowability and the significance of the anthropic principle, and he discusses his efforts as department chair to enhance diversity in the field. At the end of the interview, Albrecht discusses his current work on decoherence and einselection, and he explains why avoiding prejudices in one’s scientific sensibilities is both singularly difficult and key to unlocking future discovery.
In this interview, Jo Dunkley, professor of physics and astrophysical sciences at Princeton, discusses her life and career. Dunkley describes the nature of this dual appointment and she recounts her childhood in London and her all-girls school education. She describes her undergraduate experience at Cambridge and the formative influence of Malcolm Longair’s class on relativity. Dunkley explains that pursuing a graduate degree in physics was not a foregone conclusion, and that she initially considered a career in international development. She discusses her motivation to study under the direction Pedro Ferreira at Oxford to work on the cosmic microwave background experiments. Dunkley conveys the immediate importance of Wilkinson Microwave Anisotropy Probe (WMAP) on her thesis research and the opportunities that led to her postdoctoral work at Princeton to work with David Spergel and Lyman Page on WMAP. She explains her decision to return to the Oxford faculty to continue working with Ferreira and the origins of her involvement in the Atacama Cosmology Telescope project and subsequently the Large Synoptic Survey Telescope (LSST, now the Vera C. Rubin Observatory) endeavor and her work on it with Ian Shipsey. Dunkley discusses the challenges in maintaining a work-life balance during maternity leaves at Oxford and then at Princeton, after she joined the faculty in 2016. She describes the many exciting projects her graduate students are working on and she explains her current interests in understanding the Hubble constant. At the end of the interview, Dunkley surveys the major unanswered questions in contemporary cosmology, the viability of discovering the mass of neutrinos, and what the interplay between theory and experimentation might hold for the future.
Interview with Marc Kamionkowski, William R. Kenan, Jr. Professor of Physics and Astronomy at Johns Hopkins University. He discusses his family heritage of Ashkenazi Jews who left Eastern Europe for Argentina, and his father’s medical research which took the family to Cleveland. Kamionkowski recounts his childhood in Shaker Heights, and he describes his undergraduate work at Washington University, where he switched from pre-med to physics to work with Marty Israel and Joe Klarmann. Despite his lack of preparation, Kamionkowski explains his admission to the University of Chicago, and he describes “the bug” that made him focus on physics and drive to succeed in quantum mechanics and understand quantum field theory. He discusses his thesis research under the direction of Michael Turner on energetic neutrinos from WIMP annihilation in the sun. Kamionkowski discusses his post-doctoral research at the Institute for Advanced Study where he was in Frank Wilczek’s particle theory group. He describes his first faculty appointment at Columbia and how experimental advances had opened up opportunities in cosmology. He explains his decision to move to Caltech because of its strength in theoretical astrophysics and where he became director of the Moore Center. Kamionkowski discusses his subsequent move to Johns Hopkins, and he surveys his recent projects on the Hubble Tension and early dark energy. At the end of the interview, Kamionkowski explains why he has always valued research that bridges the divide between theory and experimentation and why he expects this will continue to inform his broad research agenda.
Interview with Rainer Weiss, professor emeritus of physics at MIT. Weiss recounts his family history in pre-war Europe and the circumstances of his parents' marriage. He describes his childhood in New York City, and he explains his interests in experimenting and tinkering from an early age. Weiss explains the circumstances leading to his undergraduate study at MIT and his original plan to study electrical engineering before focusing on physics. He recounts his long and deep relationship with Jerrold Zacharias, who singularly championed Weiss's interests over the years. He discusses his graduate work on the hyperfine structure of hydrogen fluoride. Weiss describes his formative work with Bob Dicke at Princeton, and he explains how technological advances was beginning to offer new advances in general relativity. He explains how Dicke's influence served as an intellectual underpinning for the creation and success of LIGO. Weiss emphasizes the importance of Richard Isaacson as one of the founding heroes of LIGO, and he describes the fundamental importance of joining his research institutionally with Caltech. He describes his early research with John Mather, and the numerous administrative challenges in working with the NSF throughout the LIGO endeavor. Weiss describes the geographical decisions that went into building LIGO, the various episodes when LIGO's ongoing viability was in doubt, and how both Barry Barish and Kip Thorne contributed to ensuring its success. At the end of the interview, Weiss describes some of the sensitivities regarding who has been recognized in LIGO and who has not, in light of all the attention conferred by the Nobel prize, and he reflects on how LIGO will continue to push discoveries forward on the nature and origins of the universe.
Interview with Steven Weinberg, Jack S. Josey-Welch Foundation Chair in Science and Regental Professor at the University of Texas at Austin. The focus of the interview is on how and when Weinberg became interested in cosmology, and how he defines it as a distinct discipline from astronomy and astrophysics. Weinberg explains that between the intensity of interest in particle physics in the 1950s and the speculative nature of cosmology, he had neither the interest nor the outlet to pursue cosmology in a rigorous way. He discusses some of the theoretical and experimental limitations at the time that kept cosmology in a largely “mystical” realm, and why the discovery of the microwave background by Penzias and Wilson “changed everything.” Weinberg explains what new questions can be considered as a result of evidence for a hot early universe, and he discusses when he first became interested in the formation of galaxies. He describes why the cosmological constant has bothered him for a long time, and he traces this problem back to Einstein and what Weinberg considers Einstein’s incorrect approach to his own theory. Contrasting his own experience as a graduate student, he cites John Preskill as his first student to pursue cosmology, and he explains that while his interests in particle physics and cosmology are generally separate, he always looks for intersecting research opportunities, which is well represented in the relevance of beta decay physics in the first three minutes of the universe. At the end of the interview, Weinberg surveys the value and problems associated with the term “Big Bang,” and he reflects on his career-long effort not to be dogmatic in his views on cosmology.
In this interview, David Zierler, Oral Historian for AIP, interviews Joseph Silk, Homewood Research Professor of Physics at Johns Hopkins, Researcher Emeritus at the Institute of Astrophysics in Paris, and Senior Fellow at the Beecroft Institute for Cosmology and Astro-Particle Physics. Silk recounts his childhood in London as the child of working-class parents, and he describes his early interests in math and his acceptance to Cambridge. He discusses the influence of the fluid dynamicist George Batchelor and the gravitational theorist Denis Sciama, and his decision to pursue graduate work at Manchester before enrolling at Harvard for his PhD research under the direction of David Layzer. Silk describes the revolutionary discovery of the cosmic microwave background and some of the observational advances that were driving the young field of cosmology and galaxy formation. He discusses his postdoctoral appointment with Fred Hoyle back at Cambridge and his next research position working with Lyman Spitzer at Princeton, and with Jerry Ostriker on black holes and pulsars. Silk describes the circumstances leading to his first faculty appointment at Berkeley and the excitement surrounding the high red shift universe, the birth of X-ray astronomy, and he describes Berkeley Laboratory’s gradual emphasis on astrophysics over his 30-year career at UC Berkeley. He discusses his long-term research endeavor to verify the prediction of the Big Bang theory and the incredible results of the COBE project. Silk describes his budding interests in particle astrophysics, which he considers a discipline distinct from astronomy, cosmology and astrophysics, and which grew from cosmic inflation. He describes the import and future prospects of supersymmetry, how his namesake contribution “Silk damping” came about, and he conveys his excitement about moon-based telescopes. Silk draws a distinction between understanding the very beginning of the universe (t = 0) and the tiniest fraction of time after that (t = epsilon) and why an understanding quantum gravity will be necessary to make advances in this field. He discusses the current controversy around the Hubble constant, he describes his decision to transfer from Berkeley to Oxford and how this led to his current slate of affiliations, including his appointment at Johns Hopkins. At the end of the interview, Silk discusses his current interests in the moon telescope project and what the legal ramifications of a permanent moon presence might look like and why, in his popular talks, he finds it important to project a sense of awe about the universe.
Interview with Phillip James Edwin Peebles, Albert Einstein Professor of Science, Emeritus, at Princeton University. Peebles describes his enjoyment in pursuing the issues in cosmology that are most interesting to him in retirement and he explains his appreciation for the importance of taking a sociological perspective to science. He describes his first exposure to cosmology as a field to specialize in during graduate school and he surveys some of the experiments and observational advances that have propelled theoretical cosmology. Peebles recounts his childhood in Manitoba, and he discusses his undergraduate education at the University of Manitoba. He describes arriving at Princeton in 1958 and how he became a student of Bob Dicke's. Peebles discusses his thesis research on the possibility that the fine-structure constant might be evolving. He describes staying at (and never leaving) Princeton for his postdoctoral work, and some of the exciting promises of infrared astronomy and radio astronomy. Peebles conveys the simple process of joining the faculty, and he describes the developments leading to the prediction of the cosmic microwave background. He discusses the trend of particle theorists pursuing questions in cosmology, and he reflects on the impact of the Vietnam era on Princeton. Peebles conveys the significance of the introduction of cold dark matter and his perspective on the inflationary theory of the universe. He explains why LambdaCDM has become standard in the field and why COBE was so important. Peebles surveys the many observational projects that are currently being planned, and he reflects on the "buzz" that he felt in advance of winning the Nobel Prize. He describes how his life has been affected by this honor, and he reflects on how the Department of Physics has changed over the course of his long career. At the end of the interview, Peebles emphasizes his interest in remaining close both to theory and experimentation, and he shares his sense of curiosity at what clues might be found from the epoch of light element production in the very early universe.
In this interview, Joseph Taylor, the James S. McDonnell Distinguished University Professor of Physics, Emeritus, at Princeton University, recounts his upbringing in and around Philadelphia, and the centrality of Quakerism throughout his childhood. He describes his undergraduate experience at Haverford, where he developed his interest in physics and in experimental radio astronomy specifically. Taylor discusses his graduate work at Harvard, and why the mid-1960s was an exciting time for radio astronomy, and he describes his thesis research under the direction of Alan Maxwell on observing radio galaxies and quasars to create two-dimensional maps. Taylor describes the impact of the discovery of pulsars, just as he was completing graduate school, and he explains his decision to join the faculty at the University of Massachusetts to start the Five College Radio Astronomy Observatory. He describes the fundamental advances in pulsar research in the 1970s, and he recounts his early and soon to be significant interactions with Russell Hulse, and he describes the logistical challenges of setting up research at the Arecibo Observatory. Taylor describes the intellectual origins of discovering gravitational radiation, and he explains his decision to join the faculty at Princeton which centered around its strength in gravitational physics. He discusses the long period of time between his research and the Nobel Prize for which he was recognized, and he discusses the impact of the prize on his life and his research. Taylor discusses his tenure as Dean of Faculty at Princeton, and in the last part of the interview, he describes his current and recent interests in WMAP, and why he welcomes the strides his field has taken toward greater diversity.