Quantum chromodynamics

Interviewed by
David Zierler
Interview date
Location
Video conference
Abstract

Interview with Wick Haxton, professor of physics at UC Berkeley. Haxton recounts his childhood in Santa Cruz and his early interests in math and science. He describes his undergraduate education at the newly created UC Santa Cruz where his initial interest was in mathematics before he was given the advice that he did “mathematics like a physicist.” Haxton discusses his graduate work at Stanford where his original intent was to study general relativity before he connected with Dirk Walecka and Bill Donnelly to focus on nuclear theory and dense nuclear matter. He discusses his postdoctoral research at the University of Mainz where he concentrated on photo-pion physics during the early days of chiral perturbation theory, and he explains the opportunities that led to his next appointment at the LAMPF facility at Los Alamos. Haxton emphasizes the excellence of both his colleagues and the computational capacity at the Lab, and he describes his faculty appointment at Purdue and the solar neutrino experiment he contributed to in Colorado. He explains the opportunities that led to him joining the faculty at the University of Washington where the DOE was about to fund the Institute for Nuclear Theory. Haxton explains the “breakup” between nuclear theory and particle theory and how the INT addressed that. Haxton discusses the opportunities afforded at the INT to engage in nuclear astrophysics and he explains the rise and fall of the Homestake DUSEL project. He explains his decision to go emeritus at UW and to join the faculty at UC Berkeley and to be dual hatted at the Berkeley Lab, and he describes his tenure as department chair. At the end of the interview, Haxton describes his current work organizing the new Physics Frontier Center and the challenges presented by the pandemic, and he credits his formative time as Los Alamos for the diverse research agenda he has pursued throughout his career.

Interviewed by
David Zierler
Interview date
Location
Video conference
Abstract

Interview with Ruth Van de Water, Scientist I at Fermilab. She explains the hierarchical system at the lab to explain her title and she recounts her childhood in Northern Virginia. Van de Water describes her undergraduate experience at William & Mary where she developed an interest in physics and was mentored by David Armstrong, and she describes the considerations that led to her admission to the graduate program at the University of Washington. She discusses her early involvement in the Atlas program and her thesis research that focused on computational and numerical physics and lattice QCD. Van de Water discusses her postdoctoral work at Fermilab, and she describes the state of play regarding the Tevatron and the D0 and CDF collaborations. She describes her ongoing work in lattice QCD research and the opportunity that led to her second postdoctoral position at Brookhaven, where she pursued a new approach to discretizing quarks. Van de Water describes Fermilab “poaching” her back to work on quark flavor physics and become involved in the G-2 experiment. She discusses the negative impact on a decreased budget, and her current leave from Fermilab to be a visiting professor at North Central College, and she shares that she is conflicted about continuing on a strictly research path and focusing more directly on teaching. At the end of the interview, Van de Water discusses the impact of #ShutdownSTEM and the issue of inclusivity in physics and why solutions to under-representation are not easily achievable. 

Interviewed by
David Zierler
Interview date
Location
Video conference
Abstract

Interview with Michael Dine, Professor of Physics at the University of California at Santa Cruz. Dine conveys his provisional excitement over the g-2 muon anomaly experiment at Fermilab and he recounts his childhood in Cincinnati. Dine discusses his undergraduate education at Johns Hopkins, his developing interests in physics, and the opportunity that led to his graduate research at Yale. He describes working under the supervision of Tom Appelquist and trying to understand the force between heavy quarks within quantum chromodynamics. Dine describes his earliest exposure to string theory and his decision to take a postdoctoral appointment at SLAC, where he worked with Jonathan Saperstein on the next order calculation of the total electron-positron cross section. He discusses Lenny Susskind’s work on Technicolor and his subsequent appointment at the Institute for Advanced Study, his close collaboration with Willy Fischler, and the excitement surrounding supersymmetry at the time. Dine describes the impact made by Ed Witten when he arrived in Princeton and he discusses the origins of axion-dark matter research. He discusses his first faculty position at City College in New York and his reaction to the “string revolution” of 1984 and AdS/CFT a few years later. Dine explains his decision to move to UC Santa Cruz and his burgeoning interest in cosmology, he reflects on when his research focused to physics beyond the Standard Model, and he explains why it is possible to decouple the expectation that supersymmetry must be detected at the LHC. He explains why string theory is making strides toward experimental verifiability, and he reflects on the utility of being a theorist. At the end of the interview, Dine emphasizes his optimism about the axion as a dark matter candidate and why the field is moving steadily toward a greater understanding of physics at both the largest and smallest scales.

Interviewed by
David Zierler
Interview date
Location
Video conference
Abstract

Interview with Gerard 't Hooft, University Professor of Physics (Emeritus) at Utrecht University in the Netherlands. 't Hooft considers the possibility that the g-2 muon anomaly experiment at Fermilab is suggestive of new physics, and he reflects broadly on the current shortcomings in our understanding of quantum mechanics and general relativity. 't Hooft recounts his childhood in postwar Holland and the influence of his great uncle, the Nobel Prize winner Frits Zernike and his uncle, the theoretical physicist Nico van Kampen. He describes his undergraduate education at Utrecht University where he got to know Martinus Veltman, with whom he would pursue a graduate degree and ultimately share the Nobel Prize. 't Hooft explains the origins of what would become the Standard Model and the significance of Yang-Mills fields and Ken Wilson’s theory of renormalization. He describes Veltman’s pioneering use of computers to calculate algebraic manipulations and why questions of scaling were able to be raised for the first time. 't Hooft discusses his postdoctoral appointment at CERN, his ideas about grouping Feynman diagrams together, and how he became involved in quantum gravity research and Bose condensation. He explains the value in studying instantons for broader questions in QCD, the significance of Hawking’s work on the black hole information paradox, the holographic principle, and why he has diverged with string theorists. 't Hooft describes being present at the start of supersymmetry, and the growing “buzz” that culminated in winning the Nobel Prize. He describes his overall interest in the past twenty years in thinking more deeply about quantum mechanics and he places the foundational disagreement between Einstein and Bohr in historical context. At the end of the interview, 't Hooft surveys the limitations that prevent us from understanding how to merge quantum mechanics and general relativity and why this will require an understanding of how to relate the set of all integer numbers to phenomena of the universe.

Interviewed by
David Zierler
Interview date
Location
Video conference
Abstract

Interview with Michael Creutz, Senior Physicist Emeritus at Brookhaven National Laboratory. Creutz surveys where lattice gauge theory is “stuck” and where there are promises for breakthroughs in the field. He recounts his birthplace in Los Alamos, where his father was a physicist, and his upbringing in Pittsburgh and then San Diego. Creutz describes his undergraduate education at Caltech and his graduate research at Stanford, where Sid Drell supervised his work on deep inelastic scattering. He explains his decision to take a postdoctoral position at the University of Maryland, and he discusses becoming involved in lattice gauge theory following his exposure to Ken Wilson’s work on renormalization. Creutz describes Brookhaven’s focus on proton scattering when he joined the Lab, and he explains his work during the discovery of the J/psi. He explains his motivation for writing a textbook on lattices, and the value of ever-more powerful computers for lattice gauge research. Creutz explains his “controversial” approach to staggered fermions, and his work on topology in lattice theory. At the end of the interview, Creutz discusses his current interests in chiral symmetry, he reflects on the burst of intellectual activity at the dawn of lattice gauge theory, and he explains why parity violation in neutrinos continues to confound theorists.

Interviewed by
David Zierler
Interview date
Location
Video conference
Abstract

Interview with Ian Hinchliffe, Senior Staff Emeritus at Lawrence Berkeley National Laboratory. Hinchliffe surveys the current state of play with the ATLAS collaboration. He recounts his childhood in northern England, and his interests and abilities in science that facilitated his admission to Oxford. Hinchliffe explains his decision to remain at Oxford for graduate school to work under the direction of Llewellyn Smith on deep inelastic scattering and he discusses his postdoctoral appointment at Berkeley Lab. He discusses his work in the theory group led by Geoff Chew and he explains the significance of QCD to reconcile calculations with experiments. Hinchliffe describes the opportunities that allowed him to stay at Berkeley Lab and the key developments of neutrino scattering. He discusses his involvement in supercollider physics and planning for the SSC and his tenure as leader of the theory group. Hinchliffe explains how Berkeley got involved in the ATLAS collaboration at CERN and George Trilling’s leadership of this effort, and he explains how CMS is both competitor and partner in the search for the Higgs and beyond. He conveys his feelings when the Higgs was discovered and how ATLAS has contributed to astrophysical research. At the end of the interview, Hinchliffe prognosticates on the future of CERN, and why he remains optimistic that the Higgs factory will push forward foundational discovery.

Interviewed by
David Zierler
Interview date
Location
Video conference
Abstract

Interview with Edward Witten, Charles Simonyi Professor in the School of Natural Sciences at the Institute for Advanced Study. Witten discusses his current interests in quantum information theory in gravity, and he recounts his childhood in Baltimore and the influence of his father Louis Witten, who is a physicist. He describes his undergraduate education at Brandeis, where he majored in history, a brief stint working for the McGovern campaign, and a false start in graduate school to study economics before landing at Princeton to study first applied mathematics and then theoretical particle physics with David Gross. He describes the significance of deep inelastic scattering in the emergence of QCD and his earliest exposure to the ideas that would develop into string theory. Witten describes his postdoctoral appointment at Harvard to work with Steve Weinberg, Sidney Coleman, Shelly Glashow, and Howard Georgi. He discusses t’ Hooft’s success at solving the U(1) problem and his early work in supersymmetry by the time he joined the faculty at Princeton. Witten narrates the string revolution of 1984 and the early optimism that string theory would be able to describe the real world. He describes his involvement in topological quantum field theories and he explains his decision to move to the Institute from Princeton. Witten discusses his work with Nati Seiberg on N=2 super Yang Mills in four dimensions, the origins of M-theory in the 1994 string revolution, and the impact of Juan Maldacena’s work on AdS/CFT. He describes his collaboration with Seiberg on noncommutative geometry, his interest in the Langlands program, and the role of axions in string theory. Witten conveys the sense of optimism when the LHC turned on and the significance of Khovanov homology and Morse theory. He explains the need to revisit perturbative superstring theory and the possibility that the g-2 muon anomaly experiment at Fermilab will lead to new physics. At the end of the interview, Witten reflects on how little has been seen at the LHC after the Higgs discovery, and he expresses hope that string/M-theory and quantum gravity make meaningful contact during his lifetime.

Interviewed by
David Zierler
Interview dates
July 30 and August 3, 2020
Location
Video conference
Abstract

Interview with Sylvester James Gates, Jr., Ford Foundation Professor of Physics and Director of the Theoretical Physics Center at Brown University. Gates discusses his preparations to lead the APS and the value of his service for PCAST for this new role. Gates recounts his family heritage and he discusses his father’s military service and the death of his mother. He explains how his family navigated racist challenges during his upbringing in El Paso and then in Orlando and how he navigated his own intellectual abilities in school. Gates explains his interest in physics in high school and the opportunities that led to his admission at MIT for his undergraduate work. He recounts the many mentors who made a positive impression on him and he explains his realization that his specialty would be at the boundary between math and physics. Gates describes his earliest interactions with string theory and he explains his decision to remain at MIT for his graduate work to work with Jim Young on supersymmetry. He paints a broader picture of supergravity research at this time and the rising importance of computers for this work. Gates describes his postdoctoral research at Harvard as a Junior Fellow, where he worked closely with Warren Siegel, and he describes his decision to join the faculty at MIT after a subsequent postdoctoral position at Caltech. He addresses Shelly Glashow’s criticism of string theory, and he explains his decision to leave MIT for a faculty position at the University of Maryland. Gates reflects on his teaching and mentoring career at Maryland, he describes his time at Howard University, and he discusses the broader issue of diversity in physics and AIP’s TEAM-UP Report. He describes his more recent interests in graph theory and the broader effort to unify gravity with the other forces. Gates reflects on how he became an advisor to President Obama for PCAST and how he worked with John Holdren to translate reports into policy changes. He explains his decision to go emeritus at Maryland and to take a new position at Brown, and why joining the Watson Institute was an attractive part of the offer. Gates reflects on assuming leadership at APS during the twin crises of Covid and racial strife, he surveys the state of string theory and high energy physics, and he explains why supersymmetry might offer a path to understanding dark matter. At the end of the interview, Jim conveys his hope that his work in math will yield deep insights into nature, and he considers the possibility of pursuing an autobiographical project.

Interviewed by
David Zierler
Interview dates
March 18 and April 17, 2021
Location
Video conference
Abstract

Interview with Stephen Wolfram, Founder and CEO of Wolfram Research. He describes his recent efforts to launch an “assault” on the final theory of physics and he muses on the possibility that the human mind is a quantum mechanical system. Wolfram recounts his family’s German-Jewish heritage and his upbringing in Oxford, where his mother was an academic. He describes his schooling which put him on a trajectory to skip grades and begin college at age fifteen and to complete his PhD at age twenty. Wolfram discusses his early interests in particle theory and computer systems and he describes his summer research visit to Argonne Lab and his visit with David Gross at Princeton. He explains the circumstances that led to his admission at Caltech to work on QCD and his decision to accept a faculty appointment at Caltech thereafter. Wolfram narrates the origins of the SMP program and the intellectual property issues he experienced as a Caltech professor. He explains his intellectual migration away from physics toward the work that would become Mathematica and Wolfram Language, and he describes his time at the Institute for Advanced Study. Wolfram discusses the business model he adopted for Mathematica and his educational motivations that were incorporated into the program from its inception. He discusses his interests in complex system research and his fascination with cellular automata, and he narrates the intellectual process that led to his book A New Kind of Science. Wolfram surveys the reviews, positive and negative, that he has received for this work, and he offers a retrospective look at how NKS has held up as it approaches its twentieth anniversary. He describes the launch of Wolfram Alpha and the promises and limits of quantum computing and why he has returned to physics in recent years. At the end of the interview, Wolfram asserts that he has never taken risk in any of his decisions, and he considers how his approach and the intellectual and business ventures he has pursued will continue to yield solutions for many of the ongoing and seemingly intractable problems in physics.

Interviewed by
David Zierler
Interview date
Location
Video conference
Abstract

Interview with Stanley Brodsky, Professor Emeritus at SLAC. Brodsky surveys his current projects after his retirement last year following 54 years of service to SLAC; they include new initiatives on hadron physics and his interest in the muon G-2 experiment at Fermilab. He recounts his upbringing in St. Paul, his early interests in electrical engineering, and his decision to stay close to home and attend the University of Minnesota for his undergraduate education. He explains his decision to remain at Minnesota for his thesis research, where he worked under the supervision of Donald Yennie on computing atomic levels from first principles in quantum electrodynamics. Brodsky describes his postdoctoral appointment at Columbia, where he worked with Sam Ting at DESY computing the QED radiative corrections for Bethe-Heitler pair production. He recalls his original contact with Sid Drell and his decision to come to SLAC to join the theory group in support of the many experimental programs in train, and he recounts the November Revolution and Sam Ting’s visits to SLAC. Brodsky describes some of the key differences in East Coast and West Coast physics in the 1970s, and he discusses his collaboration with Peter Lepage at the beginning of QCD’s development. He highlights the importance of thinking beyond conventional wisdom and he references his work on intrinsic heavy quarks to illustrate the point. Brodksy discusses his research on the Higgs VEV and the long range value of the Brodsky-Lepage-Mackenzie procedure, and he reflects on the many surprises in QCD color confinement that he has encountered. He explains the value of supersymmetry in his research and he considers why it has not been seen yet and why Maldacena’s work on AdS/CFT has been revolutionary. Brodsky describes SLAC’s increasing involvement in astrophysics and how he has managed his research agenda by working on many different projects at the same time. At the end of the interview, Brodsky emphasizes the significance of Bjorken scaling, he historicizes the first work in physics that explored beyond the Standard Model, and he reflects on the importance that luck has played in his career, simply by finding himself, at so many junctures, in being at the right place at the right time.