Bard Physicist Hal Haggard Coauthors New Study on Fast Spacetime Dynamics in Quantum Gravity
Dynamics has altered forever the once static arenas of space and time. Physicists have even measured spacetime deform and undulate as gravitational waves propagate away from colliding black holes. Regrettably, these dynamics have incompletely invaded the granular world of quantum gravity. In a new study, Haggard and colleagues use computer simulations to show that dynamical grains of space can be built up into a complete picture of a small but evolving quantum spacetime.
Bard Physicist Hal Haggard Coauthors New Study on Fast Spacetime Dynamics in Quantum Gravity
Dynamics has altered forever the once static arenas of space and time. Physicists have even measured spacetime deform and undulate as gravitational waves propagate away from colliding black holes. Regrettably, these dynamics have incompletely invaded the discrete, granular world of quantum gravity. In a new study in Physical Review Letters, Haggard, together with colleagues Seth Asante and Bianca Dittrich of the Perimeter Institute for Theoretical Physics, uses computer simulations to show that dynamical grains of space can be built up into a complete picture of a small but evolving quantum spacetime.
Assistant Professor of Physics Shuo Zhang discussed her current research and participated in a press briefing Tuesday, June 2, at the 236th Meeting of the American Astronomical Society. In her presentation, “Revealing the Powerful Particle Accelerator in the Galactic Center,” Zhang discussed her research exploring the nature and origin of one of the most striking phenomena in the center of the Milky Way Galaxy, the existence of dozens of filamentary structures that can be as long as hundreds of light years.
Bard Physics Professor Shuo Zhang Discusses Her Research on Galactic Center Filaments at American Astronomical Society Press Conference
Bard College Assistant Professor of Physics Shuo Zhang discussed her current research and participated in a press briefing Tuesday, June 2, at the 236th Meeting of the American Astronomical Society. In her presentation, “Revealing the Powerful Particle Accelerator in the Galactic Center,” Zhang discussed her research exploring the nature and origin of one of the most striking phenomena in the center of the Milky Way Galaxy, the existence of dozens of filamentary structures that can be as long as hundreds of light years. In a series of papers, Zhang and her research partners propose that the supermassive black hole in the Galactic center, Sagittarius A*, is the engine producing energetic particles that eventually light up these filaments in the X-ray and radio wave bands.
Zhang says the theory is supported by recent gamma-ray and radio observations. “Using observations recently obtained by the Chandra space telescope, we see evidence for new X-ray filaments,” says Zhang. “My next goal is to conduct a systematic multi-wavelength search for Galactic center filaments and use their spatial distribution and spectral information to further test our theory.”
The American Astronomical Society is the major organization of professional astronomers in North America, with a membership of 7,700 individuals with research and educational interests in astronomical sciences. The 236th meeting is the 2020 summer annual American Astronomical Society conference, which brings together the international astronomer community and shares the most recent discoveries and results in astronomy. For more information, visit aas.org.
Shuo Zhang, assistant professor of physics at Bard, is interested in observational high-energy astrophysics, including supermassive black hole accretion and feedback, origin of Galactic cosmic-rays and dark matter searches. She studies outburst histories of the supermassive massive black hole at the center of the Milky Way galaxy and nearby galaxies, in order to understand supermassive black hole activity cycle, particle acceleration mechanism and physics under strong gravitational field. Recently, she initiated an original particle astrophysics project on probing Galactic cosmic-ray particles at MeV through PeV energy scales suing innovative methods, aiming to understand the origin of Galactic cosmic-rays and to reveal power particle accelerators at the center of the Galaxy. Zhang served previously as a NASA Einstein Fellow at Boston University, and a postdoctoral scholar and Heising-Simons Fellow at the MIT Kavli Institute for Astrophysics and Space Research. In addition to her research, she is a referee for Nature, monthly notices of the Royal Astronomical Society, and a panel reviewer for NASA’s Astrophysics Data Analysis Project. She is also a member of several scientific collaborations, including Event Horizon Telescope (EHT) collaboration, eXTP Space Telescope Observatory Science Working Group, Chandra/ACIS Instrument Team, and NuSTAR Space Telescope Science Team, among others. Her work has appeared frequently in Astrophysical Journal and Monthly Notices of the Royal Astronomical Society. Zhang earned a BS degree from Tsinghua University and a PhD from Columbia University.
A broad network of Bard faculty and staff has come together to produce face shields for frontline health-care workers who are grappling with a nationwide shortage of protective gear.
Bard Connects: Faculty and Staff Get Creative to Provide Protective Gear to Regional Health Workers
“Life in the era of COVID-19, as in all times of crisis, amplifies our basic instincts. Do we become anxious or confident, selfish or generous, rigid or adaptable? The same applies to institutions. And right now, at this moment of national and global crisis, Bard College is demonstrating who we are: student-focused, innovative, entrepreneurial, and civically engaged.” —Jonathan Becker, Vice President for Academic Affairs and Director of the Center for Civic Engagement at Bard College
A broad network of Bard faculty and staff—including Ivonne Santoyo-Orozco and Ross Exo Adams in the Bard Architecture and Design Program; Maggie Hazen and Melinda Solis in Studio Arts; IT’s Doug O’Connor, Hayden Sartoris, and Christopher Ahmed; and the Philosophy Program’s Katie Tabb—has come together to produce face shields for frontline health-care workers who are grappling with a nationwide shortage of protective gear.
3D-printed face shield components.
With two 3D printers loaned by Bard physicist Paul Cadden-Zimansky, Exo Adams and Santoyo-Orozco set up a makeshift lab in Tivoli to fabricate reusable face shields for health-care workers. When the lab is fully operational, they expect to produce up to 50 shields per week. Hazen and Solis have begun a production line as well, using 3D printers purchased with proceeds from a GoFundMe campaign established by MFA alumna Luba Drozd ’15 that has raised more than $20,000. A small batch of shields has already been distributed to Columbia Memorial Hospital in Hudson, New York, and the group is now looking for more distribution options in the Hudson Valley. Deliveries of face shields are also scheduled for Albany Medical Center and, in Dover, New Jersey, Saint Clare’s Hospital, where a Bard student’s relative works and on whose behalf the student made a request. Anyone interested in distribution or in assisting with the project should contact Doug O’Connor (oconnor@bard.edu), who is centralizing the distribution efforts with the help of CCS Bard students.
And in Annandale, members of the Fisher Center’s Costume Shop—together with Audrey Smith from Buildings and Grounds, Rosalia Reifler from Environmental Services, and Saidee Brown from the President’s Office—have sewn nearly 200 face masks for the essential College employees who remain on campus.
To learn more about virtual engagement opportunities at Bard, visit Bard Connects.
Professor of Physics Hal Haggard and Colleagues Receive Buchalter Cosmology Prize for Black Hole Research
Bard College Assistant Professor of Physics Hal Haggard and his fellow researchers were awarded a 2019 Buchalter Cosmology Prize at the 235th meeting of the American Astronomical Society in Honolulu, Hawaii, on January 6. The annual prize series, created by Dr. Ari Buchalter in 2014, seeks to reward new ideas or discoveries that have the potential to produce a breakthrough advance in our understanding of the origin, structure, and evolution of the universe. Professor Haggard and his colleagues were recognized for research testing the Bekenstein-Hawking entropy of black holes.
The $5,000 Second Prize was awarded to Professor Haggard, of Bard College and the Perimeter Institute for Theoretical Physics, and colleagues from the Pennsylvania State University: Eugenio Bianchi, Anuradha Gupta, and B. S. Sathyaprakash (also of Cardiff University). The judging panel recognized their paper, “Quantum Gravity and Black Hole Spin in Gravitational Wave Observations: a Test of the Bekenstein-Hawking Entropy,” as “a remarkable test of the thermodynamic character of black holes, predicting the spin characteristics of an initial primordial population of black holes that thermalize in the early universe, and which could be detectable by current and near-future gravitational wave detectors.”
Haggard’s work is part of an ongoing scientific revolution in the study of black holes. Last year, scientists captured the first direct image of a black hole, less than four years after measuring, for the first time, the gravitational waves created by the collision of two black holes circling one another at nearly light speed. These waves directly oscillate space and time. Contrary to initial expectations, pairs of black holes crashing into each other give rise to most of the gravitational waves we can currently measure. Advanced facilities like the Laser Interferometer Gravitational-Wave Observatory (LIGO) are now observing and measuring black hole collisions about once a week.
Previously, scientists only knew about two main types of black holes: X-ray binary systems, which often contain one active star and a black hole, in the range of five to 15 times the mass of our sun, that “siphons off” mass from the donor star; and supermassive black holes, a class that includes the black hole imaged in 2019, which measures about 6.5 billion solar masses.
Prior to LIGO, physicists did not expect that the main class of binary collisions measured would be of two black holes, or that those black holes would have masses in the range of 20 to 80 solar masses. Most surprising of all, it now appears possible that most of the black holes measured through gravitational waves aren’t spinning at all before they collide. Scientists had thought that the majority of black holes were formed in the gravitational collapse of a rotating star.
Haggard and his colleagues’ paper shows that black holes formed in a different way, as part of the hot primordial soup of the early universe, could naturally have zero spin. The authors also find that these black holes would be expected to have masses of 10 to 100 times the mass of our sun. Their arguments are based on understanding how entropy and temperature determine the physical characteristics of a black hole, for example its spin.
“I’m delighted about this paper because it brings together so many of the strands of my work,” says Haggard. “Gravitational wave measurements are an exciting probe of the rich interplay between gravitational thermodynamics, black holes, and the early history of the cosmos. It is a rare point of contact between the ideas that go into a quantum theory of gravity, like black hole entropy, and experimental observations that are happening right now.”
The $10,000 First Prize was awarded to Jahed Abedi and Niayesh Afshordi for their work entitled “Echoes from the Abyss: A Highly Spinning Black Hole Remnant for the Binary Neutron Star Merger GW170817.” The $2,500 Third Prize was awarded to José Beltrán Jiménez of Universidad de Salamanca and colleagues for their work entitled “The Geometrical Trinity of Gravity.”
Dr. Buchalter, a former astrophysicist turned business entrepreneur, established the prize series in the belief that significant breakthroughs in the field of cosmology still lie ahead but might require challenging and breaking with accepted paradigms. “The 2019 prizewinners represent bold thinking that can help open up new frontiers in our understanding of physics and of the universe,” said Dr. Buchalter. The judging panel for the annual prizes is made up of leading theoretical physicists noted for their work in cosmology. The 2019 panel included Justin Khoury and Mark Trodden of the University of Pennsylvania and Lee Smolin of the Perimeter Institute for Theoretical Physics. Learn more at buchwaltercosmologyprize.org.
Underwater Laser Slicing of the World’s Thinnest Material
Bard Faculty and Students in Chemistry and Physics Collaborate on Newly Published Research
In recent years, scientists have developed a new set of techniques to thin down certain materials into sheets that are only a few atoms thick—the most famous example being graphene, a one-atom thin layer of graphite that holds the title of world’s thinnest material. Graphene and its thin cousins hold promise both for being implemented in new technology and in helping physicists understand the quantum properties of materials. In making prototype devices from them, researchers often need to shape these sheets into particular patterns with features measured in nanometers.
Noting that conventional methods for doing this require multistep processes that can damage the materials, Ethan Richman ’20 led a team of undergraduates working in the labs of Bard Chemistry Professor Chris LaFratta and Physics Professor Paul Cadden-Zimansky to pioneer a potentially cleaner and faster way of slicing graphene at the nanoscale by using a high-powered laser beam focused into a microscope. While a handful of other research groups around the world have tried using lasers for graphene slicing, the Bard researchers noticed that laser cuts in air can damage the graphene at the atomic level. Taking a cue from techniques used in industrial laser cutting, Richman tried modifying the cutting technique by submerging the graphene in water and found this improved both the quality and efficiency of the cutting. Their results are published in Optics Materials Express, with Cadden-Zimansky, LaFratta, and eight student collaborators as coauthors.
Bard Hosts Quantum Gravity Summer School for Students and Scholars from U.S. and Abroad
With Public Lecture “What Is Time?” by Carlo Rovelli, World-Renowned Scientist and Best-Selling Author, on Thursday, June 13
The Bard Summer School on Quantum Gravity takes place from June 9 to June 16. Fifty-two students from more than 20 countries will participate, plus Bard College students on campus for the Summer Research Institute. This program for undergraduate and graduate students features canonical and covariant approaches to quantum gravity and quantum cosmology. One unique feature of the program is an afternoon computing lab in which students learn a computational technique in cosmology or one in quantum gravity from scratch.
The Bard Summer School on Quantum Gravity provides free tuition and housing on the Bard College campus. The school received generous support from the Center for Gravitation and the Cosmos at Pennsylvania State University; the Perimeter Institute for Theoretical Physics; the University of Waterloo; the Division of Science, Mathematics, and Computing at Bard College; the Dean of Bard College; and the Bard Physics Program.
The eight faculty members are scholars at the top of their fields: Ivan Agullo, Louisiana State University; Boris Bolliet, Jodrell Bank Center for Astrophysics, The University of Manchester; Pietro Doná, Pennsylvania State University; Edward Wilson-Ewing, University of New Brunswick; Maïté Dupuis, University of Waterloo and Perimeter Institute for Theoretical Physics; Laurent Freidel, Perimeter Institute for Theoretical Physics; Carlo Rovelli, Centre de Physique Théorique, Aix-Marseille Université and Université de Toulon; and Sebastian Steinhaus, Perimeter Institute for Theoretical Physics.
Students in the Quantum Gravity Summer School at Bard College.
Carlo Rovelli, world-renowned scientist and best-selling author, will give a public lecture, “What Is Time?,” in Olin Hall on Thursday, June 13, at 7:00 p.m. as part of the weeklong program. Rovelli is a member of the faculty at Centre de Physique Théorique de Aix-Marseille Université et Université de Toulon, France. Rovelli writes of his upcoming lecture:
Time is a mystery that does not cease to puzzle us. Philosophers, artists and poets have long explored its meaning while scientists have found that its structure is different from the simple intuition we have of it. From Boltzmann to quantum theory, from Einstein to loop quantum gravity, our understanding of time has been undergoing radical transformations. Time flows at a different speed in different places, the past and the future differ far less than we might think, and the very notion of the present evaporates in the vast universe.
The event is free and open to the public, but reservations are required. Reserve a seat by emailing Hal Haggard (hhaggard@bard.edu). Doors open at 6:30 p.m. This event is sponsored by the Physics Program.
— Further Reading —
Jim Bardeen, Hal Haggard, and Carlo Rovelli, faculty members in the Bard Summer School on Quantum Gravity, weigh in on “White Holes: Black Holes’ Neglected Twins,” in Space.
Bard Alum, Physics PhD Candidate Ingrid Stolt ’15 on the Magic of Magnets
At age seven, Bard alum Ingrid Stolt ’15 fell in love with the magnets on her parents’ refrigerator: “I used to pretend that one magnet was a magic wand that was causing the other to move back and forth and rotate through supernatural powers. Magnetism seemed magical because it was so mysterious, yet I wanted to understand how it worked.” Today, she's a fourth-year doctoral student in physics, helping to develop practical uses for superconductivity at Northwestern's Nuclear Magnetic Resonance Laboratory.
Join our December graduating seniors in presenting their senior projects Reem-Kayden Center6:00 pm – 7:30 pm EST/GMT-5 Light refreshments will be served.
Friday, December 7, 2018
Sarah Ballard Massachusetts Institute of Technology Hegeman 10712:00 pm – 1:00 pm EST/GMT-5 The Solar System furnishes our most familiar planetary architecture: many planets, orbiting nearly coplanar to one another. However, a typical system of planets in the Milky Way orbits a much smaller M dwarf star. Small stars present a very different blueprint in key ways, compared to the conditions that nourished evolution of life on Earth. My research program combines detailed individual planetary studies with ensemble studies of hundreds-to-thousands of exoplanets. Single planets provide crucial case studies, but understanding planet occurrence and formation requires a wider lens. I will describe ongoing efforts to understand the links between planet formation from disks, orbital dynamics of planets, and the content and observability of planetary atmospheres. Studies of exoplanets with the James Webb Space Telescope comprise the clear next step toward understanding the hospitability of the Milky Way to life. Our success hinges upon leveraging the many thousands of planet discoveries in hand to determine how to use this precious and limited resource.
Friday, November 2, 2018
Dr. Kathryn E. Stein ’66 Reem-Kayden Center Laszlo Z. Bito '60 Auditorium5:00 pm – 7:00 pm EST/GMT-5 Kathryn Stein ’66, PhD, an immunologist with more than 30 years of experience, received the John and Samuel Bard Award in Medicine and Science from Bard College.
Friday, October 26, 2018
Alison Crocker, Reed College Hegeman 10712:00 pm – 1:00 pm EST/GMT-5 Early-type galaxies (elliptical and lenticular galaxies) are high-entropy stellar systems, all galaxies will eventually tend toward such states (perhaps sped up by interactions with other galaxies). Many early-type galaxies are also high-entropy gaseous systems, essentially with hot gas atmospheres maintained by energy input from their central super-massive black hole, not entirely differently than how central nuclear reactions support stars. However, some early-type galaxies still contain low-entropy, cold gas. In these cases, the galaxies are not quite in an ``end state”. I will discuss possible evolutionary pathways and physical processes that explain how some early-type galaxies still have cold gas reservoirs.
Friday, October 12, 2018
Hegeman 10712:00 pm – 1:15 pm EST/GMT-5 Room Acoustic Criteria and Theoretical Construction Yu-Tien (James) Chou
What Makes Black Holes Spin? Mac Selesnick
Building a Radio Interferometer Isobel Curtin
Efficiency in Aviation: Gliders, Drones, and Bears, Oh My! Rory Maglich
Drone Analysis Kyle Zigner
Friday, October 5, 2018
Antonios Kontos, Physics Program, and Christopher LaFratta, Chemistry Program Hegeman 10712:00 pm – 1:00 pm EST/GMT-5 The 2018 Nobel Prize in Physics was awarded to Arthur Ashkin “for the optical tweezers and their application to biological systems” and jointly to Gérard Mourou and Donna Strickland “for their method of generating high-intensity, ultra-short optical pulses.” In this talk, we will go through these groundbreaking laser developments and the impact they have had on precision measurements.
Thursday, October 4, 2018
Reem-Kayden Center6:00 pm – 7:30 pm EST/GMT-5 Join faculty and students who participated in this year’s program in presenting their work.
Friday, September 28, 2018
Hegeman 10712:00 pm – 1:00 pm EST/GMT-5 Gold Microplating Kyle Zigner Bard College Mentor: Christopher LaFratta
Building a Shot-Noise Limited Laser Bruno Becher Bard College GO lab Mentor: Antonios Kontos
Simulating Frequency Eigenmodes of LIGO Mirrors Isobel Curtin Bard College GO lab Mentor: Antonios Kontos
Multilayer Coating Calculations Logan Kaelbling Bard College GO lab Mentor: Antonios Kontos
Optical Coherence Tomography Setup for the Study of LIGO Mirrors Andrew Poverman Bard College GO lab Mentor: Antonios Kontos
Friday, September 21, 2018
Massimo Schuster Olin Hall7:00 pm – 9:00 pm EST/GMT-5 Through various anecdotes, some true, some made up, but always plausible, I start with Thales, move on to Empedocles and Aristarchus, spend some time with Plato and Aristotle, then jump all the way to Einstein. All along, I use a simple language, understandable to everyone and hopefully entertaining. My goal is to explain how the world in which we live is at the same time simpler and more complex, but most of all more marvelous and fascinating, than most people think.
Without trying to sell myself as a specialist of scientific thinking, which I'm not, my goal is to explain why physics is for me a constant source of inspiration and wonder.
The show is free and open to the public. However, we ask that you reserve a seat by emailing Hal Haggard (hhaggard@bard.edu)
Friday, September 21, 2018
Massimo Schuster Hegeman 10712:00 pm – 1:00 pm EST/GMT-5 Doing science is one (great) thing; talking science is something else, especially if you talk to people who are not science-minded. It can also be great, but for some people it's harder than for others. As an actor and storyteller I think that there are a few tips that I can share and that will be helpful to you scientists and/or scientists-to-be, whenever you'll be talking to an audience. This will not be a lecture, nor a workshop, rather a freewheeling exchange.
Friday, September 14, 2018
Hegeman 10712:00 pm – 1:00 pm EST/GMT-5 Underwater Laser Ablation of Graphene Grey MacAlaine, Cameron Miller, and Ethan Richman Bard College Nanolab and Columbia University Mentor: Paul Cadden-Zimansky
Micro-Hydro Summer Internship Eva Grunblatt Bard College and Current Hydro Mentors: Jan Borchert, Matthew Deady, Joel Herm, Laurie Husted and Richard Murphy
The Development and Evaluation of the Ho'ouna Pono Drug Prevention Curriculum Nathalie Jones Hawaii Pacific University Mentor: Scott Okamoto
Friday, September 7, 2018
**required for all lab use excepting lab courses** Reem-Kayden Center Laszlo Z. Bito '60 Auditorium3:00 pm – 4:00 pm EST/GMT-5
Thursday, September 6, 2018
**required for all lab use excepting lab courses** Reem-Kayden Center Laszlo Z. Bito '60 Auditorium4:30 pm – 5:30 pm EST/GMT-5
Wednesday, September 5, 2018
**required for all lab use excepting lab courses** Reem-Kayden Center Laszlo Z. Bito '60 Auditorium4:00 pm – 5:00 pm EST/GMT-5
Friday, June 15, 2018
Jennifer L. Carter, SUNY Albany Reem-Kayden Center Laszlo Z. Bito '60 Auditorium3:30 pm – 4:30 pm EST/GMT-5 The idea that worlds exist beyond our solar system, exoplanets, dates back to the Greek times, but it was not until 1992 that the first exoplanet discovery was accepted by the scientific community. Detections of exoplanets continued at a crawl until the Kepler mission began in 2009. To date, over 3,700 exoplanets have been confirmed using a variety of techniques. The types of exoplanets detected range from incredibility hot, Jupiter-size exoplanets to Earth-like exoplanets that may be habitable for life.
First, we’ll discuss the motivation behind exoplanet science and explore the subject from a historical perspective. We will investigate how some of the detection methods work and discuss their relative successes. Finally, we will conclude by exploring the reflected light of exoplanets in more detail and will discuss two methods of modeling that light.
Thursday, May 17, 2018
8:30 pm – 10:00 pm EST/GMT-5 Buses leave from Kline South stop at 8:30 pm.
Join us at the Montgomery Place visitor center for a short talk by Prof. Antonios Kontos on the science of Jupiter—from the days of Galileo to the latest NASA missions—followed by telescope viewing of Jupiter and its moons, a guided tour of the night sky, and a round of ask-a-physicist-anything.
Thursday, May 17, 2018
Join Science, Mathematics & Computer graduating seniors in presenting their senior projects. Reem-Kayden Center6:30 pm EST/GMT-5
Friday, May 11, 2018
Xuemei May Cheng | Bryn Mawr College Hegeman 10712:00 pm – 1:00 pm EST/GMT-5 Nanostructured materials are materials with one or more dimensions at the nanoscale (10-7-10-9 meters). Examples of nanostructured materials include 2-dimensional ultrathin films, 1-dimensional nanowires, 0-dimensional nanodots, and more complex structures that could have a combination of these characteristics. Nanostructured materials often exhibit new and enhanced properties over their bulk counterparts, so they not only offer ideal material systems for exploring fundamental physics, such as magnetic topological phases, but also hold promise for applications in data storage and biomedical engineering. In this talk, I will report our experimental work on 2D multilayers that host magnetic skyrmions, topologically protected spin textures that have promising applications in Spintronic data storage devices, as well as our work on magnetic disks that form the magnetic vortex state, useful for biomedical applications.
Friday, May 4, 2018
Paul H. Halpern, University of the Sciences Hegeman 10712:00 pm – 1:00 pm EST/GMT-5 Richard Feynman, the Nobel Laureate whose centenary we are celebrating on May 11, was one of the most important American theoretical physicists of all time. His diagrams are used every day in characterizing particle interactions. In my talk, I'll explore how he was influenced by his PhD mentor at Princeton, another well-known physicist, John Wheeler. I'll discuss how the lifelong interplay between the two physicists helped shape Feynman’s key contributions to physics and physics pedagogy, despite clear differences in style and personality between the two.
Friday, April 20, 2018
Rose Finn, Siena College Hegeman 10712:00 pm – 1:00 pm EST/GMT-5 A long-standing problem in extragalactic astronomy is to understand the correlation between a galaxy's environment and its ability to form new stars. The fraction of red galaxies is much higher in dense environments, whereas blue, star-forming galaxies are more prevalent in rural galactic environments. One could therefore infer that environment plays a role in removing gas from galaxies and may help drive a galaxy's transition from blue and star-forming to red and quiescent. However, many other galaxy properties correlate with environment, such as mass and morphology. I will present results from the Local Cluster Survey, a survey whose goal is to look for evidence of environmentally driven quenching among star-forming galaxies in nearby galaxy groups and clusters. We have studied 200 galaxies over a range of stellar mass, morphology, and environment in an effort to separate the influence of these factors. We find that galaxies in dense environments have more centrally concentrated star formation, and the presence of a bulge seems to enhance the effectiveness of environmental processing. Our results suggest that galaxies in dense environments experience outside-in quenching over a timescale of several gigayears. I will also discuss new work that probes galaxies in the filamentary structure around the Virgo cluster, and the possibility for completing observations of these filament galaxies using Siena College's new telescope.
Friday, April 6, 2018
Michel Janssen, University of Minnesota Hegeman 10712:00 pm EST/GMT-5 There is a striking difference between the methodology of the young Einstein and that of the old. Starting in the late 1910s, Einstein went from putting empirical data and general physical principles first to putting mathematical elegance first. This switch was the result both of his scientific experience finishing the general theory of relativity and his crushing personal and political experiences during the war years in Berlin. In crisis situations like this, Einstein, invoking Schopenhauer, used science to escape from it all. Building mathematical castles in the sky was better for this purpose than trying to extract information about nature from empirical data. In his later years, Einstein worked mainly in this mathematical speculation mode. The older man accordingly left us with a misleading picture of how his younger self achieved most of the successes for which he is still celebrated today. This has had a harmful influence on theoretical physics. If the young Turk’s successes are any guide as to how successful theoretical physics is done, paying close attention to general features of the empirical data is much more important, and mathematical elegance much less important, than the old sage wanted us to believe.
Spencer Weart, former director of the American Institute of Physics Center for History of Physics Hegeman 10712:00 pm EST/GMT-5
The history of how we learned about climate change offers a deep look into the way scientists work and how that has changed. When 19th-century scientists discovered the Ice Ages they came up with various explanations, including a decrease of carbon dioxide in the atmosphere. Could humanity’s fossil fuel emissions bring a reverse effect, global warming? The idea found only a few supporters, curious scientists who stepped aside from their usual research to develop “greenhouse gas” calculations and measurements. By 1960 they proved that the idea merited serious research. An onslaught of droughts in the early 1970s brought public attention to climate and intensified research, typically by small teams, but scientists admitted they could not even predict whether the world would get warmer or colder. This was resolved at the end of the 1970s by computer models that found global warming would become obvious around 2000. The implication that the fossil fuel industries must be radically reduced brought political pushback and scientific controversy. Crucial confirmation of the models came from a totally independent direction: research on climates of the distant past (studies that were themselves confirmed through independent lines of attack). Large-scale teamwork was now necessary to advance, and almost no climate scientist worked alone. When the world’s governments devised a novel mechanism to get scientific advice, hundreds and then thousands of experts in diverse fields managed to cooperate. By 2001 they reached a nearly unanimous consensus: dangerous climate change is all but certain within our lifetime. The focus of research turned to the impacts.
Spencer Weart is a historian specializing in modern physics and geophysics. He received a B.A. in physics at Cornell University and a Ph.D. in physics and astrophysics at the University of Colorado, Boulder. He then worked on solar physics at the California Institute of Technology and the Mount Wilson and Palomar Observatories, publishing papers in leading scientific journals. In 1971 Dr. Weart changed fields, enrolling as a graduate student in the history department at the University of California, Berkeley. In 1974 he became director of the American Institute of Physics Center for History of Physics and its Niels Bohr Library, continuing until his retirement in 2009. Meanwhile, he taught undergraduate and graduate courses on history of science at the Johns Hopkins University, the Eugene Lang College of the New School in New York City, and Princeton University. He has published books and articles on a variety of subjects, mostly related to the history of physics. Best known are Nuclear Fear: A History of Images (1988; revised as The Rise of Nuclear Fear, 2012), and The Discovery of Global Warming (2003, rev. ed. 2008; translations in six languages), and maintains an extensive scholarly website on the history of climate change research, https://history.aip.org/climate/.
Discover Physics at Bard
Hal Haggard, Director Physics Program Bard College | PO Box 5000 Annandale-on-Hudson, NY 12504 haggard@bard.edu | 845-758-7302
