Theoretical physics

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.

In this interview, David Zierler, Oral Historian for AIP, interviews Leonard Susskind, Felix Bloch Professor of Theoretical Physics at Stanford University.  Susskind recounts his childhood in the Bronx, and describes his good fortune of being the product of public education in New York from elementary school through CCNY for college. He discusses his discovery that he had a talent for physics, and the difficulties he faced convincing his father that that he would pursue this path and not join in the family plumbing business. Susskind explains the formative advice given to him by professor Harold Rothbart, and the influence of Jesse Douglas and Harry Soodak on his intellectual development as a theorist. He recounts his experience in graduate school at Cornell, where he worked under the direction of Hans Bethe calculating the ground state of infinite nuclear matter. He describes his studies under Richard Feynman and how he admired Feynman’s ability to cut through problems.  Susskind discusses his teaching career at the Belfer Graduate School of Science at Yeshiva University, and he provides an intellectual history for the origins of string theory starting with Geoffrey Chew and the S-matrix of hadronic collisions, culminated in the Veneziano amplitude by Gabriele Veneziano, and he describes his contributions from there, for which he is popularly knows as one of the “fathers” of string theory.  He describes joining the faculty at Stanford, he discusses the advances made by Stephen Hawking, and he asserts that our understanding of the origins of the universe remain at the primitive stage. Susskind explains why he is devoted to explaining physics concepts to broad-based audiences, and he explains what he sees as the most critical threats posed by the Trump administration.  In part II, the interview returns to Susskind’s early years, and he recounts his father’s support for civil rights, and how this influenced his own politics in the 1960s. He describes his goals in his debate with Lee Smolin and engages in some of the spiritual and metaphysical implications that can arise from studying the universe.  At the end of the interview, Susskind reviews, over the course of his career, the ways string theory has, and has not, contributed to efforts to unify all theories of physics, and he affirms that he more closely aligns with Einstein’s approach not to tolerate a clash of physics principles, over that of Niels Bohr.

In this interview, Steven Koonin, University Professor at New York University, recounts his childhood in Brooklyn and his education at Stuyvesant High School, which he credits for providing an excellent education in math and science. He explains his decision to pursue a degree in physics at Caltech, where Willie Fowler supervised him, and where he focused on nuclear physics. Koonin discusses his graduate work at MIT, where he studied under Art Kerman and focused on Hamiltonian variational principles for quantum many-body systems and on the study of nuclear motion. He explains the opportunity that led him back to Caltech for his first faculty position without going through a postdoctoral experience first. He describes his interest in then doing a postdoc in Copenhagen, where he had more opportunities to collaborate on theoretical nuclear physics than at Caltech. Koonin describes the pleasures of teaching quantum mechanics to undergraduates, he describes the impact of personal computing technology on his research in the mid-1980s, and he discusses his contributions in extrapolating nuclear reactions to get astrophysical rates. Koonin discusses his involvement in national security issues including the Strategic Defense Initiative as part of the JASON group, and his advisory work for the Department of Energy and DARPA. He describes his administrative accomplishments as vice president at provost at Caltech and the institutional advancements that he fostered in biology and high-performance computing. Koonin explains his position to take a position at BP as chief scientist where he had a mandate to push the company to pursue alternative energy resources, and he describes his decision to accept Steve Chu’s offer to run the Office of Science at DOE during the first Obama administration. Koonin describes his focus there on exascale computing and high-energy density science, and he discusses his long-range interest in climate science and some of the inherent challenges this field presents in both the scientific and political realms. He describes his decision to accept his current position at NYU, and at the end of the interview, Koonin describes his goals in founding the Center for Urban Science and Progress. 

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. 

Interview covers the development of several branches of theoretical physics from the 1930s through the 1960s; the most extensive discussions deal with topics in quantum electrodynamics, nuclear physics as it relates to fission technology, meson field theory, superfluidity and other properties of liquid helium, beta decay and the Universal Fermi Interaction, with particular emphasis on Feynman's work in the reformulation of quantum electrodynamic field equations. Early life in Brooklyn, New York; high school; undergraduate studies at Massachusetts Institute of Technology; learning the theory of relativity and quantum mechanics on his own. To Princeton University (John A. Wheeler), 1939; serious preoccupation with problem of self-energy of electron and other problems of quantum field theory; work on uranium isotope separation; Ph.D., 1942. Atomic bomb project, Los Alamos (Hans Bethe, Niels Bohr, Enrico Fermi); test explosion at Alamagordo. After World War II teaches mathematical physics at Cornell University; fundamental ideas in quantum electrodynamics crystalize; publishes "A Space-Time View," 1948; Shelter Island Conference (Lamb shift); Poconos Conferences; relations with Julian Schwinger and Shin'ichiro Tomonaga; nature and quality of scientific education in Latin America; industry and science policies. To California Institute of Technology, 1951; problems associated with the nature of superfluid helium; work on the Lamb shift (Bethe, Michel Baranger); work on the law of beta decay and violation of parity (Murray Gell-Mann); biological studies; philosophy of scientific discovery; Geneva Conference on the Peaceful Uses of Atomic Energy; masers (Robert Hellwarth, Frank Lee Vernon, Jr.), 1957; Solvay Conference, 1961. Appraisal of current state of quantum electrodynamics; opinion of the National Academy of Science; Nobel Prize, 1965.

In this interview, David Zierler, Oral Historian for AIP, interviews Gino Segrè, emeritus professor of physics and astronomy at the University of Pennsylvania. Segrè recounts his childhood in Italy and his family’s abrupt exit for the United State before the outbreak of World War II. He discusses his life in New York, and his family’s decision move back and forth from Italy. Segrè discusses his undergraduate experience at Harvard and his graduate research at MIT. He discusses his work on field theory at Berkeley, and his decision to join the faculty at Penn where he set about helping to build up the elementary particle physics program. Toward the end of the interview, Segrè discusses his developing interests as a science writer, the present course of theoretical particle physics and the importance for physicists to reinvent themselves over the course of their careers.

In this interview, David Zierler, Oral Historian for AIP, interviews Bertrand Halperin, Hollis Professor of Mathematicks and Natural Philosophy, Emeritus, at Harvard. Halerpin recounts his upbringing and education in Brooklyn, and his decision to study at Harvard as an undergraduate. He describes some of the leading physicists of the department during that time, and his developing interest and talent for theory. Halperin describes a formative summer internship at New York Life Insurance Company and his work at the dawn of the computer age, and another summer internship at Los Alamos, where he worked on a project on neutron scattering from aluminum. He explains his decision to move to Berkeley and then Princeton for graduate school where he developed his interest in solid state physics. Halperin describes his post-doctoral work in France and his subsequent job at Bell Labs, where he worked on dynamic critical phenomena. He describes being recruited back to Harvard by Paul Martin and his subsequent work on quantum Hall effects and one-dimensional systems research. In the last exchange of the interview, Halperin describes his current interests in experimental puzzles and the behavior of quantum systems.

AIP Oral Historian David Zierler interviews Dr. Mary Gaillard, Professor of the Graduate School, University of California, Berkeley and Affiliate Senior Scientist at Lawrence Berkeley Laboratory. Dr. Gaillard discusses her experiences as an undergraduate at Hollins College in Virginia, and as a graduate student first at Columbia University, then at the University of Paris at Orsay. She describes her subsequent research on kaons and baryon decay while working for the French National Center for Scientific Research at CERN, her year-long collaboration with Ben Lee at Fermilab, and her eventual return to the United States as the first woman to be a tenured professor in the Department of Physics at UC Berkeley, focusing in particular on the working environment at each institution. The remainder of the interview deals with the state of theoretical physics over the course of her career and through to the present.

Edward Gerjuoy ws born in Brooklyn, New York, on May 19, 1918, of a Romanian immigrant mother and Russian immigrant father. He attended Thomas Jefferson High School, along with other classmates who became well-known physicists. He studied at City College of New York. He was minimally involved in the Young Communist League. He completed the Ph.D. in physics under J. Robert Oppenheimer at the University of California, Berkeley, in 1942. Gerjuoy discusses his teachers, professors, and fellow students. He describes the classroom atmosphere, the personalities, and the courses. Gerjuoy, who learned no calculus in high school, became a theoretical physicist, specializing in quantum mechanics. During World War II, Gerjuoy worked as a civilian scientist on anti-submarine warfare, ultimately leaving a Sonar Analysis Group under Lyman Spitzer. After the war, he taught at the University of Southern California, New York University, and the University of Pittsburgh. He also worked at Westinghouse Research Laboratory, General Atomic Laboratory, and directed a plasma research group at RCA Laboratories in New Jersey. At age 56, Gerjuoy decided to take a sabbatical and started a degree in law. While on leave from the University of Pittsburgh, he served as one of three judges on the Pennsylvania Environmental Hearing Board. He nevertheless remained active in the American Physical Society, especially on the Committee on the International Freedom of Scientists (CIFS) and the Panel on Public Affairs (POPA). He played a role in the Wen Ho Lee case regardin gnational security matters at Los Alamos. He was editor-in-chief of Jurimetrics Journal of Law, Science, and Technology for six years. His interest in recent years relates to quantum computing.

Edward Gerjuoy ws born in Brooklyn, New York, on May 19, 1918, of a Romanian immigrant mother and Russian immigrant father. He attended Thomas Jefferson High School, along with other classmates who became well-known physicists. He studied at City College of New York. He was minimally involved in the Young Communist League. He completed the Ph.D. in physics under J. Robert Oppenheimer at the University of California, Berkeley, in 1942. Gerjuoy discusses his teachers, professors, and fellow students. He describes the classroom atmosphere, the personalities, and the courses. Gerjuoy, who learned no calculus in high school, became a theoretical physicist, specializing in quantum mechanics. During World War II, Gerjuoy worked as a civilian scientist on anti-submarine warfare, ultimately leaving a Sonar Analysis Group under Lyman Spitzer. After the war, he taught at the University of Southern California, New York University, and the University of Pittsburgh. He also worked at Westinghouse Research Laboratory, General Atomic Laboratory, and directed a plasma research group at RCA Laboratories in New Jersey. At age 56, Gerjuoy decided to take a sabbatical and started a degree in law. While on leave from the University of Pittsburgh, he served as one of three judges on the Pennsylvania Environmental Hearing Board. He nevertheless remained active in the American Physical Society, especially on the Committee on the International Freedom of Scientists (CIFS) and the Panel on Public Affairs (POPA). He played a role in the Wen Ho Lee case regardin gnational security matters at Los Alamos. He was editor-in-chief of Jurimetrics Journal of Law, Science, and Technology for six years. His interest in recent years relates to quantum computing.