Cosmology

Interview with Wendy Freedman, John & Marion Sullivan University Professor and senior member of the Kavli Institute for Cosmological Physics at the University of Chicago. She recounts her childhood in Canada, her early interests in science, and her decision to attend the University of Toronto, where she developed an interest in astronomy. She cites the Canada France Hawaii Telescope as the reason she stayed at Toronto for graduate school to work under the direction of Barry Madore. Freedman describes her postdoctoral appointment at Carnegie Observatories to work on the Cepheid distance scale, and she explains her decision to accept a position on the permanent staff at Carnegie. She narrates the origins of the Hubble Space Telescope Key Project, and she explains the resistance among theorists regarding the existence of the Hubble constant. Freedman discusses the importance of CCDs to measure the Hubble constant, and she marvels at Hubble’s long and productive life. She explains the inspiration for starting the Giant Magellan Telescope as an international collaboration, and she explains the opportunities that led to her becoming director of Carnegie. Freedman surveys the cooperative nature between the GMT and LSST projects and she projects optimism that GMT will propel fundamental advances in black hole research and for the search for exoplanets and possible for life beyond earth. She explains her decision to join the faculty at Chicago and she expresses pleasure at being able to work with students as a professor. At the end of the interview, Freedman reflects on the increasing complexity and expense of large-scale astronomy research and why it is important that the astronomy community relates its work and discoveries to the broader public.

Interview with John Hawley, John D. Hamilton Professor of Astronomy, and Senior Associate Dean for Academic Affairs in the College of Arts and Sciences at the University of Virginia. Hawley discusses his responsibilities as Associate Dean and he conveys his ongoing interest in black hole observational work and in the future findings of the James Webb Telescope. He reflects on his career’s overlap with the rise of computational astrophysics and he explains why he is agnostic on the hypothetical value of quantum computing to the field. He recounts his childhood in Maryland, then Kansas, and then northern California, in support of his father’s work as a minister, and he describes his undergraduate education at Haverford where he developed his interest in astronomy. Hawley explains his decision to work with Larry Smarr as his advisor at the University of Illinois, and he describes the origins of the Supercomputing Center. He describes the opportunities that led to him to Caltech to work with Roger Blandford, who was working on jets and active galaxies, and where he pursued synergies between analytic and computational analyses of black hole research. Hawley emphasizes the proximity to NRAO that influenced his decision to accept an offer from UVA, and he discusses his foundational collaboration with Steven Balbus on accretion disks. He explains his motivation to write the textbook Foundations of Modern Cosmology, what it was like to win the Shaw Prize, and how his administrative responsibilities gradually and mostly overtook his research agenda. At the end of the interview, Hawley reflects on the complementary nature of his technical collaboration with Balbus, and why he thinks terms of numerical and analytical approaches as separate endeavors.

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.

Interview with Lee Smolin, Founding and Senior Faculty Member at the Perimeter Institute with faculty appointments at the University of Toronto and the University of Waterloo. Smolin narrates the origins of the Perimeter Institute and he describes his unorthodox views on what exactly cosmology is. He describes loop quantum gravity and the notion of a “theory of everything” and why he has much love for string theory despite perceptions of the opposite. Smolin explains the utility and trappings of the Standard Model and he searches for deeper meaning in the origins and societal impact of the pandemic. He recounts his childhood in Cincinnati and his early appreciation for physics and the circumstances that led to his undergraduate education at Hampshire. Smolin explains his attraction in working with Sidney Coleman at Harvard, and why he saw a grand plan in his desire to learn quantum field theory. He describes meeting Abhay Ashtekar and his postdoctoral work at UC Santa Barbara and then at the Institute for Advanced Study. Smolin describes his formative relationship with Chandrasekhar at Chicago, his first faculty appointment at Yale, and his tenure at Syracuse where he found a strong group in relativity and quantum gravity. He explains his reasons for transferring to Penn State and his involvement in loop quantum gravity achieving a mature state amid a rapidly expanding “relativity community” throughout academic physics. He describes his time at Imperial College, where he developed a quantum gravity center with Chris Isham and he historicizes the technical developments that connected his theoretical work with observation. Smolin describes his book "The Life of the Cosmos" and his foray into thinking about biology and why he identifies as a self-conscious Leibnizian who tries to connect cosmology with the concept of a god and the centrality of astrobiology to these issues. At the end of the interview, Smolin explains why he continually returns to quantum gravity, and he conveys his interest in keeping philosophy at the forefront of his research agenda.

Interview with Stuart Shapiro, Professor of Physics and Astronomy at the University of Illinois at Urbana-Champaign. Shapiro discusses the relationship between physics and astronomy at Illinois and the shifting boundaries between cosmology, astrophysics, and astronomy. He recounts his childhood in Connecticut and his fascination with the space race. Shapiro describes his undergraduate experience at Harvard in the late 1960s and the import of the discovery of the cosmic wave background. He explains his interest in general relativity as the motivating factor for his choice of Princeton for graduate work, where he worked under the direction of Jim Peebles on gas accretion onto black holes. Shapiro describes his postdoctoral appointment at Cornell and the formative collaboration he developed with Saul Teukolsky. He describes the computational advances that propelled the field of numerical relativity and how his interactions with Kip Thorne provided an early entrée to the LIGO endeavor. Shapiro explains how he and Teukolsky challenged the cosmic censorship hypothesis and how Penrose responded to this challenge. He explains his decision to join the faculty at Illinois where he continued to work on neutrino astrophysics and the prospects for observation of hypermassive neutron stars. Shapiro explains his motivations in writing "Numerical Relativity" and he compares his reactions to the detection of gravitational waves with LIGO and the imaging of a black hole with the Event Horizon Telescope. At the end of the interview, Shapiro surveys his current interests in the dynamical problems associated with dark matter. He also conveys his deep love of sports and some unlikely coincidences he has experienced in his many years of being a fan.

Interview with Adam Riess, Bloomberg Distinguished Professor at Johns Hopkins, and Distinguished Astronomer at the Space Telescope Science Institute. Riess explains the value of his dual affiliation and his focus on calibrating the Hubble Telescope for cosmological experiments. He recounts his childhood in New Jersey and the “boot camp” style of physics education he received at MIT. Riess explains his decision to go to Harvard for his graduate work, where Bob Kirshner advised his thesis research on supernovae, while he worked closely with Bill Press on data analysis. He describes his field work at Mount Hopkins in Arizona and his use of the early internet to collect and share data, and he explains what we did not previously understand about supernovae and how that prevented an earlier understanding that the universe’s expansion is accelerating. Riess describes working closely with Brian Schmidt and Nick Suntzeff and how the High-Z team came together, and he explains the decision to use the term “accelerating” to describe the findings from the research. He describes being unprepared for the enormous reaction the High-Z team received after it published its findings, and he explains the opportunities that led to his staff appointment at Space Telescope. Riess narrates his sense of when the “buzz” for the Nobel Prize started and he related the sense of bedlam when the announcement was made and his immediate plan to make this a recognition for the entire High-Z team. He explains how the world of dark energy research has opened up since the discovery and he surveys advances in instrumentation that have propelled the field forward in the last twenty years. At the end of the interview, Riess discusses his current focus on the Hubble tension, he conveys his excitement for the launch of the James Webb Telescope, and he shares that he can’t wait to meet students that he has never seen in person after a year of pandemic-mandated virtual interactions.

In this interview, Paul Steinhardt, the Albert Einstein Professor in Science at Princeton, recounts his childhood in Miami and his undergraduate experience at Caltech, where he became interested in theoretical physics and where Feynman played a key influence on his development. He surveys where physics is stuck and compares similar challenges that both string theory and inflation are facing, and he explains his reasons for going to Harvard for his graduate work. Steinhardt describes being a student of Sidney Coleman’s and his focus on gauge theories. He discusses his postgraduate work at IBM Research and as a Junior Fellow at Harvard, and he explains the opportunity that led to his faculty appointment at the University of Pennsylvania. Steinhardt describes his increasing interest in cosmology and the influence of Alan Guth. He explains his dual interest in condensed matter physics and where he saw commonality with his cosmological research. Steinhardt conveys the importance of his collaboration with Dov Levine and he explains why he thinks the notion of a multiverse is nonscientific but not necessarily impossible. He explains his focus on quasicrystals for a time at the exclusion of cosmology, and the circumstances leading to his decision to join the faculty at Princeton which was a central point for research on the cosmic wave background. Steinhardt discusses his work on dark energy and the cosmological constant and his related interactions with Michael Turner. He describes his efforts to link the mystery of the Big Bang with the physics that can be understood after the beginning of the universe, and why the notion of the universe having a clear beginning is problematic. Steinhardt describes his frustration with string theorists who are working on abstract rather than existential research problems, and he surveys the technological advances that could make some of the intractable puzzles in cosmology testable, including the bouncing model of cosmology. He relates an epic story of mineral mining in pursuit of earthly quasicrystals, and at the end of the interview, Steinhardt describes his search for good puzzles as the common thread that connects all of his research. 

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.  

Edward “Rocky” Kolb is the Director of the Kavli Institute for Cosmological Physics at the University of Chicago and the Arthur Holly Compton Distinguished Service Professor of Astronomy at the University of Chicago. In this interview, Kolb explains how he acquired his nickname and he recounts his upbringing in New Orleans and his habit of spending time in the local library, where he developed his interest in science. He describes the financial constraints that compelled him to attend the University of New Orleans for college, and he characterizes his education there as broad but not deep, which caused him to consider a wide range of specialties for his graduate research at the University of Texas. Kolb describes working with his graduate advisor Duane Dicus in applying particle physics to cosmological questions, and he summarizes his dissertation research on the effects of axions in stars. He discusses his postdoctoral research with Willy Fowler at Caltech, and he emphasizes the influence of Allan Sandage on his decision to focus on cosmology.  Kolb describes his second postdoctoral fellowship at Los Alamos where he joined the burgeoning astrophysics group in the Theoretical Division to work on Big Bang nucleosynthesis.  He explains his decision to join the astrophysics group at Fermilab, where he collaborated closely with Michael Turner and benefited from the support of Leon Lederman. He describes his developing interest in supersymmetry and neutrino oscillations, he describes the impact of Alan Guth’s lectures on inflation, and he explains his increasing involvement with the astronomy and astrophysics department at the University of Chicago culminating with an offer for him to become chair of the department.  He describes his objectives and achievements in that position, he explains how he maintained research interest in creating particles from the vacuum, and he describes how this research could be of value in the ongoing quest to understand dark matter. At the end of the interview, Kolb reflects on the different approaches that religion and science take to understanding reality, and he explains why he is most optimistic that understanding dark matter is the most likely major future breakthrough in his field.

David Wenner is a retired businessman and consultant who curated the rare physics manuscript library that would eventually become the Wenner Collection at the Niels Bohr Library. In this interview, Wenner recounts his childhood in Florida and describes his early interests in sports and academics. He describes his interest in pursuing a liberal arts education as an undergraduate at Yale, and he discusses his graduate work in computer science at Purdue. Wenner discusses his professional experiences at Texas Instruments and his long career in consulting at McKinsey & Company. He explains how he became involved with the Kavli Institute for Theoretical Physics at UC Santa Barbara and how an interest in reading physics books grew into a full time pursuit curating what would become a singular library of rare physics manuscripts. Wenner describes how he built the collection and the various considerations that led to him deciding to work with AIP and to create the Wenner Collection. He describes the process that went into his book History of Physics, and he discusses his current interest collecting manuscripts relating to climate change. At the end of the interview, Wenner reflects on ongoing questions raised by cosmology and quantum theory.