Interferometry

Interview with Kenneth Kellermann, American astronomer at the National Radio Astronomy Observatory. The interview focuses on Kellermann’s role in the early development of very long baseline interferometry (VLBI), beginning in the 1960s. Kellermann goes into detail about the collaborations on VLBI between the American, Australian, and Swedish scientific communities. He also describes the informal exchanges he took part in with Russian scientists. Kellermann discusses the network of scientists from both the US and USSR that worked together on VLBI, and he speaks on his relationship with Iosif Shklovsky. The interview then shifts to Kellermann’s work on the search for extraterrestrial intelligence, beginning with his time in Australia. He talks about various SETI conferences, particularly the First Soviet-American Conference on Communication with Extraterrestrial Intelligence in 1971 in Byurakan. The interview concludes with Kellermann sharing his current thoughts on SETI and how the work has changed over time.

Interview with Kenneth I. Kellermann, emeritus Chief Scientist at the National Radio Astronomy Observatory (NRAO), the 2024 Jansky Lecturer, and a pioneer in American radio astronomy. The interview begins with Kellermann recounting his childhood in New York, highlighting his early education and the influences that led him to pursue a career in science. He shares his experiences at MIT, discussing the pivotal moments that sparked his interest in physics and radio astronomy. Kellermann then describes his transition to Caltech, where he studied under the mentorship of John Bolton, and his significant graduate work on the spectra of radio sources. Kellermann details his postdoctoral experiences at the Parkes Observatory in Australia, where he conducted groundbreaking observations of Mercury, Venus, and Mars. He explains the collaborative nature of early radio astronomy, emphasizing the importance of mentorship and his hands-on approach to research. Kellermann also discusses his time as the director at the Max Planck Institute for Radio Astronomy, reflecting on the professional networks and opportunities that shaped his career. At the end of the interview, Kellermann highlights the challenges and rewards of working in astronomy, emphasizing the role of serendipitous scientific discovery.

Interview with Savas Dimopoulos, Professor of Physics at Stanford University. The interview begins with Dimopoulos reflecting on how the pandemic has affected his research, and he gives his initial impressions on the g-2 muon anomaly experiment at Fermilab. He discusses the push and pull between theory and experimentation when searching for physics beyond the Standard Model. Dimopoulos then recounts his early childhood in Turkey, where his family was part of the Greek minority. Due to ethnic tensions, he fled with his family to Athens as refugees. Dimopoulos remembers his early exposure to math and physics and being torn between the two. He describes moving to the US at age 18 for his undergraduate studies at University of Houston. Dimopoulos then recounts his inclination toward theory and his acceptance at University of Chicago to pursue his graduate studies under Yoichiro Nambu. He discusses his post-doctoral appointment at Columbia which then led to an offer from Stanford. He explains his research in baryogenesis and technicolor, as well as his brief time at Harvard with Howard Georgi. Dimopoulos talks about his return to Stanford, his work at CERN, and his research on large extra dimensions with Dvali and Arkani-Hamed. He concludes the interview with predictions for the future of physics beyond the Standard Model.

Interview with Barry Barish, Linde Professor of Physics Emeritus at Caltech, where he retains a collaboration with LIGO, and Distinguished Professor of Physics at UC Riverside. Barish recounts his childhood in Los Angeles and emphasizes that sports were more important than academics to him growing up. He explains his decision to attend Berkeley as an undergraduate, where his initial major was engineering before he realized that he really loved physics, and where he was advised by Owen Chamberlain. Barish describes the fundamental work being done at the Radiation Lab and how he learned to work the cyclotron. He explains why Fermi became his life-long hero and why he decided to stay at Berkeley for graduate school, even though the school’s general policy required students to pursue their doctoral work elsewhere. Barish describes his graduate research under the direction of Carl Hemholz, and he explains how he developed a relationship with Richard Feynman which led to his postdoc and ultimately, his faculty appointment at Caltech. He discusses how his interest in neutrinos led to his work at Fermilab and why the big question at the time was how to discover the W boson. Barish describes his key interests in magnetic monopoles and neutrino oscillations, and he describes his involvement with the SSC project through a connection with Maury Tigner at Berkeley, which developed over the course of his collaborations with Sam Ting. He explains that his subsequent work with LIGO never would have happened had the SSC been viable, and he describes his early connection as a young student learning general relativity as a connecting point to LIGO. Barish describes his general awareness of what Rai Weiss had been doing prior to 1994 and he relates the state of affairs of LIGO at that point. He conveys the intensity of his involvement from 1994 to 2005 and he describes the skepticism surrounding the entire endeavor and what success would have looked like without any assurance that the experiment would actually detect gravitational waves. Barish describes the road to detection as one of incremental improvements to the instrumentation achieved over several years, including the fundamental advance of active seismic isolation. He narrates the day of the detection, and he surveys the effect that the Nobel Prize has had on the LIGO collaboration and its future prospects. Barish notes the promise that AI offers for the future of LIGO, and he prognosticates the future viability of the ILC. At the end of the interview Barish explains what LIGO has taught us about the universe, and what questions it will allow us to ask in the future as a result of its success. 

Interview with Gabriela Gonzalez, Louisiana State University Boyd Professor in the Department of Physics and Astronomy. Gonzalez explains how the pandemic has slowed down data analysis for LIGO, and she recounts her childhood in Cordoba, Argentina. She describes her early interests in science and her physics education as an undergraduate in Cordoba. Gonzalez explains the circumstances that led to her graduate studies at Syracuse University where she studied relativity under the direction of Peter Saulson, and where she first became involved with LIGO. She discusses her postdoctoral appointment at MIT to work in Rai Weiss’s group, and she explains LIGO’s dual goals of detecting gravitational waves and building precision instruments toward that end. Gonzalez explains her decision to join the faculty at Penn State and she describes the site selection that led to the detection facility in Livingston, Louisiana. She describes the necessary redundancy of the LIGO detectors at Livingston and Hanford, Washington, and the importance of “locking” the mirrors on the detectors. Gonzalez describes the overall scene at LIGO in the months up to the detection and the theoretical guidance that improved the likelihood of success. She describes the intensive communication and data analysis to confirm the detection prior to the announcement, and she explains how she felt honored as part of the overall Nobel Prize award and subsequent celebration. Gonzalez describes LIGO’s work in the current post-detection period, and her own focus on diagnostics of the data, and she explains why this work, and the constant concern in missing something important, can be stressful. At the end of the interview, Gonzalez surveys what mysteries LIGO can, and cannot, solve, and she conveys optimism for LIGO’s long-term prospects to continue to push fundamental discovery. 

Interview with Alan Rogers, Research Affiliate and retired as Associate Director of the MIT Haystack Observatory. Rogers discusses his current work on the EDGES project and he suggests the possibility that this research will yield insights on the nature of dark energy. He recounts the circumstances of his birth in Rhodesia and the opportunities that led his family to the United States. Rogers discusses his education at MIT, his interest in radio astronomy, and his research under the direction of Alan Barrett. He narrates the origins of Very Long Baseline Interferometry and its application at the Haystack Observatory. Rogers explains geodesy and why the Mansfield Amendment changed the funding structure at Haystack. He describes becoming Associate Director of Haystack and how he became involved in cell phone infrastructure projects in the 1990s. Rogers explains how EDGES started, its value for measuring ozone concentrations, and he discusses his work for the Event Horizon Telescope. He explains his research contributions for the discovery of hydrogen in the early, cold universe and the value he places on the SRT telescope for educational purposes. At the end of the interview, Rogers explains his desire to expand understanding of low-frequency arrays, particularly in the SKA.

Interview with Nergis Mavalvala, Kathleen and Curtis Marble Professor of Physics and Dean of the School of Science at MIT. Mavalvala surveys her administrative focus as Dean in a time of the pandemic, and to foster inter-departmental research. Mavalvala recounts her childhood in Karachi, Pakistan, and her Zoroastrian heritage, and she explains the opportunities that led to her coming to the United States where she pursued her undergraduate education at Wellesley and she developed her skills in experimental physics and in the machine shop. She describes her decision to attend MIT for graduate school, and she narrates meeting Rai Weiss and her involvement in the LIGO project. Mavalvala describes coming to understand her queer identity in graduate school and her understanding of the complex arrangement between Caltech, NSF, MIT and the detector sites in Washington state and Louisiana. She discusses her postdoctoral position with the LIGO group at Caltech and her focus on mirror interferometry and Caltech’s support in securing her green card. She explains her decision to return to MIT to join the faculty and the transition to Advanced LIGO. Mavalvala narrates the excitement and moment of LIGO’s detection of gravitational waves, and she explains what it means to detect them and the broader technical, theoretical and astrophysical significance of this achievement. She describes the careful analysis to confirm that data and the excitement surrounding the announcement, and she discusses the generosity in the way that Kip Thorne, Barry Barish, and Rai Weiss accepted the Nobel Prize. Mavalvala emphasizes all of the applied scientific discovery achieved through the creation of the LIGO instrumentation, and she talks about her work as a professor and mentor to graduate students. She explains her decision in accepting the dean position and how she maintained an active research agenda. At the end of the interview, Mavalvala describes all of the fundamental discovery that can be made as the LIGO collaboration charts its future.

This is an interview with David Shoemaker, Senior Research Scientist at MIT, with an affiliation at the Kavli Institute for Astrophysics and Space Research. Shoemaker explains the relationship between LIGO, the MIT Department of Physics, and Kavli, and describes how these relations have changed over the years. He recounts his upbringing in Virginia, then Walla Walla, then Eugene Oregon, and then in New Jersey, where he spent his formative years, as his family moved to accommodate his father’s career. Shoemaker discusses his academic and social troubles in high school, and his undergraduate experience at Drew and then Tufts, where he majored in physics. He explains why he did not complete his undergraduate degree, and how he got to know Rai Weiss and the opportunity he offered to work as a technical instructor in the MIT Junior Lab. Shoemaker describes his decision to enroll in MIT’s graduate program, and he describes the Lab’s role in the COBE endeavor and the FIRAS interferometer project. He describes his work at the Max Planck Institute where he continued his focus on building interferometers, and he explains his decision to move to France to work with Alain Brillet. Shoemaker recounts his decision to return to MIT at the point that Weiss was becoming further involved in the LIGO effort and was forging partnerships with Caltech toward that end. He narrates the point at which MIT institutionally began to support the Lab’s work, and he emphasizes that the support predated any notion of LIGO’s success as a foregone conclusion. Shoemaker explains the early successes and promises of Advanced LIGO, and he provides a detailed account of the detection of gravitational waves, and the significance of this discovery. He describes the day of the Nobel announcement, and reflects on the impact of the attention LIGO received for the prize, for better and worse. Shoemaker discusses the post-Nobel life of LIGO and how, in many ways, the detection should be understood as a starting point for further additional discovery and not just the coda of a decades-long endeavor. At the end of the interview, Shoemaker muses on what lessons might be drawn from his experiences and the improbable nature of his successes in the field relative to the academic challenges he faced earlier in life. 

Work at Lebedev Physics Institute; study of radio-wave propagation interrupted by World War II; returns to Institute after being wounded, begins study of nonlinear radiophysics; synchrotron radiation in microwave region; starts accelerator group (Nicolai Basov)i switches to microwave spectroscopy (Charles Townes, Walter Gordy), 1950; ruby crystals (Dr. Manenkov); Prokhorov proposes use of interferometer; gas-dynamic CO₂ laser, 1966. Commercial application of lasers in USSR future laser applications.

Clauser discusses his father's influence; early interest in electronics; undergraduate study in physics at California Institute of Technology in early 1960s; graduate study at Columbia University in the late 1960s; research on the Bell inequalities as a post-doc at University of California, Berkeley with C. H. Townes in the 1970s; collaboration with Abner Shimony and Michael H. Horne; atom interferometry and its possible applications; quantum mechanics and its conceptual problems.