Dark matter (Astronomy)

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 Joel Primack, Distinguished Professor of Physics Emeritus at the University of California, Santa Cruz. Primack discusses what he has been able to do in his free time since his retirement, including writing papers, giving lectures, hosting meetings at UC Santa Cruz, leading international collaborations, and supervising research. He sees the new data coming from the Vera Rubin Observatory and the Gaia Survey as exciting developments in the realm of astrophysics, and he is looking forward to adding to this data when we begin receiving images from the James Webb Space Telescope. Primack discusses his work with various simulations that he has utilized to understand what may be occurring within galaxies, and the growing importance of astrobiology in these simulations. He takes us back into his early years in Montana, where his passion for science began to develop, and how his high school education and internships led him to Princeton University for his undergraduate career. While at Princeton, Primack took classes from John Wheeler, worked at the Jet Propulsion Lab under Bill Pickering, and participated in the Students for a Democratic Society, where his interest in the combination of politics and science began to grow. Primack discusses how important the communication between politicians and scientists is, and he saw this need for improved communication early on. He started the Congressional Science and Technology Fellowship program as a preliminary way to work on the relationship between government and science. He then recounts his experiences at Harvard University and his eventual move to Santa Cruz, where he continued working on dark matter and dark energy, among other things. He remarks on his relationship and work with Nancy Abrams, including the courses they taught and the books they wrote together. He ends the interview talking about his family, his recovery from cancer, and the people he’s looking forward to working with in the future.

Elliott Bloom, Professor Emeritus of Particle Physics and Astrophysics at SLAC, recounts his childhood in Brooklyn and then in Los Angeles, and he describes his early interests in physics. He discusses his undergraduate experience at Pomona College where he became interested in particle physics and cyclotrons. Bloom describes his graduate work at Caltech, where he worked under the direction of R.L. Walker and did his thesis experiment on studying gamma ray production of charged pions from hydrogen or deuterium. He discusses his postdoctoral research at SLAC to work with Richard Taylor, who was building spectrometers in End Station A at the end of the linear electron accelerator. Bloom discusses his early interests in online computing and he describes the origins of the Parton model and his collaboration with Joe Ballam on BC-42. He explains his original involvement with axion research and the significance of the DORIS-II storage ring at DESY. Bloom discusses his subsequent work at the SLAC B-factory on PEP-II, he describes his interests in the COBE satellite, and he explains SLAC's entrée into astrophysics. He discusses the collaborative effort with NASA on the GLAST experiment and his focus with DOE support to understand dark matter. At the end of the interview, Bloom reflects on his career trajectory as part of a larger narrative of particle physicists who became engaged in astrophysics later in their careers, and why it is important for physicists to remain open to new avenues of inquiry.

In this interview, Bernard Sadoulet, Professor of the Graduate School at the University of California, Berkeley, discusses his time working in France as well as the study of dark matter. He discusses getting his Master’s degree in theoretical physics at the University of Paris in Orsay, and how this background was beneficial for his interest in experimental physics. Sadoulet speaks about his time working at CERN as part of the official committee managing the collaboration between Europe and the Soviet Union. He also details his work on the UA1 experiment while at CERN. He describes his role in the “Wise Men Committee,” and there task of producing a report about civil nuclear programs in France. Sadoulet discusses his time as a postdoc at Berkeley and his discovery of the Chi states. He speaks about his growing interest in dark matter in the 1980s and the interest he had in the possibility of building detectors to search for dark matter particles in the halo of our galaxy. He describes his collaborations with Blas Cabrera Navarro at the Center for Particle and Astrophysics. Lastly, he reflects upon how to meaningfully involve the public in science.

Interview with Phiala Shanahan, assistant professor of physics in the Center for Theoretical Physics at MIT. Shanahan explains the administrative relationship between the department and the Center, and she recounts her childhood in Adelaide, Australia, her experiences at an all-girls school and the benefits this conferred in nurturing her interest in science. She discusses her concentration in computational physics and the mass of the H-dibaryon at the University of Adelaide and her decision to stay on with her undergraduate advisors, Anthony Thomas and Ross Young, for graduate school. Shanahan describes her interest in the proton radius puzzle as a research entry point for her thesis work and why she was interested in how particle physics can be connected more rigorously to quarks, gluons, and ultimately chemistry. She describes the opportunities leading to her postdoctoral research at MIT and some of the cultural adjustments she had to make coming from Australia. Shanahan discusses her collaboration with Will Detmold and she describes her contributions to the NPL-QCD research project and she discusses her first faculty appointment at William & Mary before returning to MIT where she remains in her current appointment and where she is pursuing work on proton structures and in creating ever-faster algorithms. She describes the potential benefits that would be conferred with the availability of true quantum computing for her field, and she describes some of the difficulties she has faced as a woman in getting recognized for her accomplishments in her field of research. At the end of the interview, she emphasizes why her long-term goal is to bridge nuclear physics and chemistry, and why she wants to keep an open mind about pursuing other areas that are both interesting and offer the opportunity to push forward discovery in foundational ways.

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 Scott Tremaine, emeritus professor at the Institute for Advanced Study in Princeton. Tremaine discusses his current affiliation with the University of Toronto, and he provides a historical overview of the boundaries between astronomy and astrophysics. He recounts his childhood in a town north of Toronto, and he explains his early interests in science. Tremaine describes his undergraduate experience at McMaster, the opportunities that led to his graduate admission to Princeton, and the exciting developments that compelled him to focus his thesis research on astrophysics. He describes his dissertation on the dynamics of galaxies done under the direction of Jerry Ostriker, who at the time was focused on the earliest research on dark matter. Tremaine discusses his postdoctoral term at Caltech where he worked with Jim Gunn and Peter Goldreich, and he explains his decision to take a second postdoctoral position at the Institute of Astronomy at Cambridge. He describes his appointment at the Institute for Advanced Study, his decision to join the faculty at MIT, and he explains his ongoing research collaboration with Goldreich on studying Saturn's rings. Tremaine describes the intellectual origins of his book, co-authored with James Binney, Galactic Dynamics, and he explains his decision to join the University of Toronto to become the director of CITA. He describes his interests in the origins of comets, his contributions to black hole research, and his appointment at the Institute for Advanced Study. Tremaine discusses his work on exoplanets, and at the end of the interview, he surveys the importance of increasing computational power over the course of his career, the exciting advances that have been made in understanding galaxy development, and why the "three-legged" stool upon which cosmology rests - namely, on inflation, dark matter, and dark energy, is problematic.

Interview with Marcelle Soares-Santos, assistant professor of physics at the University of Michigan. Soares-Santos recounts her childhood in Brazil, her early interests in science, and her graduate work in physics at the University of São Paulo. She describes her graduate visit to Fermilab to study galaxy clusters as a way to map the history of the expanding universe, which formed the basis of her thesis research. Soares-Santos discusses her return to Fermilab as a postdoctoral researcher, where she joined the Dark Energy Survey, and she explains how DES is getting us closer to understanding what dark energy is. She describes Fermilab’s broad-scale transition into astrophysics, and she explains the opportunities that led to her faculty appointment first at Brandeis before moving to Michigan. Soares-Santos discusses her current work in gravitational waves, and she prognosticates on what the discovery of dark energy (or energies) will look like. She shares her perspective on recent efforts to improve diversity and inclusivity in STEM. At the end of the interview, Soares-Santos explains why observation is leading theory in the current work of astrophysics and cosmology and why she is optimistic for fundamental advances in the field.

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.

In this interview, David Zierler, Oral Historian for AIP, interviews Marjorie Shapiro, Professor of Physics at UC Berkeley and Faculty Senior Scientist at Lawrence Berkeley National Laboratory. Shapiro describes the value of this dual affiliation and she surveys the current state of play at the LHC and its work on dark matter research, and what physics beyond the Standard Model might look like. She recounts her upbringing in Brooklyn and her father’s work as a medical physicist, and she explains the opportunities that led to her undergraduate admission at Harvard. Shapiro describes her immediate attraction to experimental particle physics and some of the challenges she faced as a woman. She explains her decision to go to Berkeley for graduate school, where the Lab was a specific draw and where she worked under the direction of Dave Nygren, whose group was working on the Time Projection Chamber. Shapiro describes her postdoctoral appointment back at Harvard to work on the CDF collaboration with Roy Schwitters, who was CDF spokesman at the time. She explains the exciting discoveries at Fermilab, her involvement in B physics, and the friendly competition with DZero. Shapiro explains that her first faculty appointment at Harvard was never something that she assumed would be long term, and the circumstances leading to her appointment at Berkeley. She explains Berkeley’s pivot to CERN following the cancellation of the SSC and the trajectory of the ATLAS program to study electroweak symmetry breaking, and she discusses her advisory work on HEPAP. Shapiro narrates the buildup and elation surrounding the discovery of the Higgs and she describes her accomplishments as the first woman to chair the Department of Physics at Berkeley. She discusses her post-Higgs concentration on SUSY and she explains that in addition to pursuing physics beyond the Standard Model and why the LHC data suggests that there remains much to be learned within the Standard Model. At the end of the interview, Shapiro explains why there remains fundamental unanswered questions on CP violation, and she explains why young physicists should pursue their research in the broadest possible way.