Fermilab colloquium calendar archive 2020

  Appropriate for physicists     Appropriate for all lab staff and members of the public
Raw date Event date Title Speakers Host Summary Links
20200101 Jan. 1, 2020 No colloquium
20200108 Jan. 8, 2020 Open
20200115 Jan. 15, 2020
How nuclear physics can treat cancer - radiotherapy at TRIUMF
Cornelia Hoehr, TRIUMF Victor Scarpine Besides being Canada’s particle accelerator centre with emphasis on nuclear, particle and accelerator physics, TRIUMF has a long history of medical isotope production and radiotherapy. Cancer treatment with different particles has been a long-standing commitment at TRIUMF, first with pion therapy and then with proton therapy, for many years operating Canada’s only proton therapy facility.... More » Video
20200122 Jan. 22, 2020 Open
20200129 Jan. 29, 2020 Open
20200205 Feb. 5, 2020
The Quantum-Mechanical Measurement Problem and the Foundations of Statistical Mechanics
David Z. Albert, Columbia University Dan Hooper It turns out that a promising proposal for solving the Quantum-Mechanical measurement problem – which is the central problem at the foundations of quantum mechanics – may shed an important and unexpected new light on the nature and the origins of the probabilities at the foundations of Statistical Mechanics. I will begin by reviewing the measurement problem, and I will give a very brief overview of various attempts at solving it. Then I will focus in on one family of such attempts - the theories of the so-called “spontaneous localization” of the wave-function. And finally, I will show how those theories – if they turn out to be true - can explain the origin of the statistical-mechanical probabilities that we need to account for (say) the second law of thermodynamics, and (more generally) for all of the rest of the special sciences. Video
20200212 Feb. 12, 2020 Open
20200219 Feb. 19, 2020
Muon Accelerators and Results from the MICE Experiment
Professor Daniel Kaplan, Illinois Institute of Technology Chris Stoughton To date most accelerators have used beams of stable particles: electrons, positrons, protons, or ions. High-brightness muon beams could facilitate the study of lepton–antilepton collisions at extremely high energies and provide well characterized neutrino beams. Such muon beams could be realized using ionization cooling, proposed some 50 years ago to increase muon-beam brightness. Ionization cooling of muons has now been demonstrated by the MICE experiment. Passage of the MICE muon beam through an energy-absorbing medium was observed to move muons from the tail of the beam into the core, increasing its phase-space density. The consistency of the measured results with the simulated performance of the apparatus validates designs of ionization cooling channels in which the cooling process is iterated to produce a substantial cooling effect. These results are an important step towards a possible future muon collider to search for phenomena at energy scales beyond the reach of the Large Hadron Collider at a facility of equivalent or reduced footprint. Video
20200226 Feb. 26, 2020
The Trouble with Quantum Physics, and Why It Matters
Adam Becker, Author and Astrophysicist Dan Hooper Quantum physics is arguably the most successful scientific theory ever devised. It explains an enormous variety of natural phenomena to an extraordinary degree of accuracy  — everything from semiconductors to the Sun itself. Yet there is a problem: it's unclear what this immensely fruitful theory says about reality. What is going on in the world of quantum physics? Why does "measurement" play a special role in the theory? Is it really impossible to talk about what's happening to atoms and subatomic particles when we're not looking at them? For many years, the standard answer to questions like this was to "shut up and calculate," to ignore these issues and simply use quantum physics to predict the outcomes of experiments. There was also a historical myth that went along with this answer, a myth that said Einstein had once worried about these questions, but he was shown the error of his ways by the great Danish physicist Niels Bohr. Yet that myth is simply untrue, and these thorny quantum paradoxes are far more important than most physicists once believed. In this talk, I'll explain the puzzles at the heart of quantum physics, why they matter, and what really went down between Einstein and Bohr 90 years ago. Video
20200302 March 2, 2020
Special Colloquium - Darkly Charged Dark Matter
Lisa Randall, Harvard University Pushpa Bhat Generally physicists assume that dark matter is a single particle with no interactions in its own sector. We demonstrate that these assumptions are not necessarily true. In particular we show that dark matter can be charged under its own force, even if as light as the weak scale. We furthermore consider the possibility that only a fraction of the dark matter is charged, and can even form a disk inside the Milky Way. Video
20200304 March 4, 2020
Consciousness and the Collapse of the Wave Function
David Chalmers, New York University Dan Hooper Two of the hardest problems in contemporary science are the problem of quantum measurement and the problem of consciousness. There is a long history of trying to link them by arguing that consciousness plays a role in quantum measurement through the collapse of the wave function. This idea has never been made rigorous. I will explore ways of making it rigorous by combining it with mathematical theories of the brain-consciousness relation and of quantum collapse dynamics. I will also discuss possible empirical tests and philosophical consequences. Video
20200311 March 11, 2020 Canceled - no colloquium
20200318 March 18, 2020 No colloquium
20200325 March 25, 2020
CANCELED - no colloquium
20200401 April 1, 2020
ZOOM MEETING: The Evolution of Language
Professor Frederick L. Coolidge, PhD, University of Colorado, Colorado Springs Chris Stoughton Zoom meeting
While the presence of different languages throughout the world is undeniable, the origin of language and its evolution is highly contentious. In part, the problem is that, unlike fossils, languages, especially unwritten languages (before about 4000 BC), do not preserve. There is virtually no evidence of their nature: This means that we do not know what these languages sounded like: For example, did they sing to express their thoughts, did they whistle, did they use gestures while they spoke, or gestures alone? Another major problem with understanding how languages got their start is that the single most influential linguist in the last seven decades, Noam Chomsky, claims language did not evolve but appeared suddenly by one gene in one person 100,000 years ago. The purpose of the present talk is to explain why Chomsky is wrong, how language did evolve, why people speak, and why the most popular topic in all the world’s cultures is gossip.
20200408 April 8, 2020
ZOOM ONLY: Black Holes in the Early Universe
Dan Hooper, Fermilab Chris Stoughton Cosmology textbooks typically assume that the early universe was dominated by relativistic particles. But if even a relatively small number of black holes were created after inflation, they would make up an increasingly large fraction of the total energy density as space expands. I'll argue that it is well-motivated to scenarios in which the early universe included an era in which low-mass (<10^8 grams) primordial black holes dominated the total energy density. Within this context, I'll discuss Hawking radiation as a mechanism to produce both dark radiation and dark matter. I'll also talk about the possibility that these black holes may have undergone mergers before evaporating, leading to potentially detectable gravitational waves signals, and to the production of a "hot graviton background".
20200415 April 15, 2020
ZOOM ONLY: New technologies for new discoveries: ProtoDUNE at CERN for the international DUNE mega-science project in the US
Flavio Cavanna, Fermilab Chris Stoughton If you are interested in attending this zoom meeting, please email Barb at kronkow@fnal.gov for the zoom information. Experimental discoveries in the last decades have placed neutrinos in the spotlight to unlock the mysteries of the matter abundance unbalance in the Universe and the ultimate fate of the stars. The Deep Underground Neutrino Experiment (DUNE) is the new leading-edge, international mega-science experiment for neutrino science and searches for physics beyond the Standard Model. DUNE will use the state-of-the-art liquid-argon (LAr) TPC technology to instrument, deep underground at the SURF Laboratory in the US (SD), up to 70,000 tons of liquid argon at 87 K achieving millimetre-scale 3D precision. A ~1 kton precursor of the DUNE LArTPC detector has been constructed and activated at the CERN Neutrino Platform. After a first exposure to low energy charged particle beams, just before the CERN accelerator complex long shut down, ProtoDUNE-SP has now collected 500+ days of continuing operation recording cosmic ray data. A second 1 kton prototype, ProtoDUNE-DP - implementing the dual phase variant of the LArTPC technology - came online more recently and is now taking data. The spectacular events collected and the extraordinary performance of the LArTPC technology open the way for discoveries with DUNE. Video
20200422 April 22, 2020 CANCELED
20200429 April 29, 2020
ZOOM ONLY: A new frontier in the search for dark matter
Gordon Krnjaic, Fermilab Chris Stoughton The gravitational evidence for the existence of dark matter is overwhelming; observations of galactic rotation curves, the CMB power spectrum, and light element abundances independently suggest that over 80% of all matter is “dark” and beyond the scope of the Standard Model. However, its particle nature is currently unknown, so discovering its potential non-gravitational interactions is a major priority in fundamental physics. In this talk, I will survey the landscape of light dark matter theories and introduce an emerging field of fixed-target experiments that are poised to cover hitherto unexplored dark matter candidates with MeV-GeV masses. These new techniques involve direct dark matter production with proton, electron, and *muon* beams at various facilities including Fermilab, CERN, SLAC, and JLab. Exploring this mass range is essential for fully testing a broad, predictive class of theories in which dark matter abundance arises from dark-visible interactions in thermal equilibrium in the early universe. Video
20200506 May 6, 2020
ZOOM ONLY: AI for Particle Physics: Better, Smarter, Faster
Kevin Pedro, Fermilab SCD/PPD Chris Stoughton Artificial intelligence (AI) and particle physics have a long and productive history together. Recent advances in deep neural networks (DNNs) have led to significant improvements in the accuracy of particle identification, among other areas.  We continue to explore cutting-edge techniques such as graph neural networks, which generalize the representation of our data to exploit as much information as possible. With the coming flood of data from the High Luminosity LHC and other intensity frontier experiments, we must increase the processing speed as well as the accuracy of our algorithms. AI satisfies both of these goals, as DNN inference can be massively accelerated using GPU or FPGA coprocessors. Connecting to coprocessors as a service minimally impacts the existing computing model, while facilitating the next generation of particle physics results. Video
20200513 May 13, 2020
ZOOM ONLY: Seeing the Milky Way with new eyes
Susan Gardner, University of Kentucky Chris Stoughton Low-energy precision measurements in Earth-based experiments can reveal "new physics" even in complex systems, through an observed breaking of the symmetries we would expect the system to possess. The advent of the "big data" era in astronomy, as exemplified by the second data release of the Gaia space telescope, opens an analogous paradigm of discovery. We can search for symmetry breaking in samples of millions of stars, to reveal and refine aspects of the Milky Way's history and ongoing dynamics. I will illustrate the former by noting examples of experimental searches for matter-antimatter (CP) symmetry breaking and then carefully consider symmetry breaking and its implications in the Milky Way, noting that current observations reveal a Milky Way that is neither isolated nor in a steady state. Video
20200520 May 20, 2020 CANCELED
20200527 May 27, 2020
ZOOM ONLY: WFIRST: Dark Energy and Exoplanets
Jason Rhodes, NASA JPL Chris Stoughton The top recommendation for a large space mission in the US 2010 Decadal Survey was the Wide Field Infrared Survey Telescope (WFIRST), which is now on schedule for launch in 2025. Similarities in hardware requirements between proposed dark energy cosmology, exoplanet microlensing, and near infrared surveyor missions allowed for a single mission that would accomplish all three goals. The gift of an existing 2.4 meter telescope to NASA by another US government agency allowed for the addition of a coronagraph that will take images and spectra of nearby exoplanets; this instrument will be a technological stepping stone to imaging other Earths in the 2030s. I will give an overview of WFIRST's instrumentation, science goals, and implementation plan. Video
20200603 June 3, 2020 Open
20200610 June 10, 2020 Open
20200617 June 17, 2020
ZOOM ONLY: Origami and Spacecraft Structures - Current Work and a Brief History
Manan Arya, Jet Propulsion Laboratory Chris Stoughton The mathematics, physics, and engineering of origami is a thriving field of academic research. We will discuss the origin and the maturation of the formal study of paper folding. Of the many applications of origami, this talk will focus on the design of deployable elements for spacecraft. Using specific examples from current work at JPL on starshades and solar arrays, this talk will highlight recent advances in origami engineering and its application to unfoldable spacecraft structures. Video
20200624 June 24, 2020
ZOOM ONLY: “Restoring the Sense of Touch and Movement Using a Brain-Computer Interface: Controlling Multiple Devices with Your Thoughts”
Patrick Ganzer, Battelle Chris Stoughton Severe spinal cord injury disrupts communication between the brain and limbs, leading to paralysis and an inability to feel. Importantly, technologies are now being developed to reconnect the brain back to the body, reverse paralysis, and even restore the sense of touch following a severe spinal cord injury. At the Battelle Memorial Institute, we have recently developed a brain-computer interface (BCI) that can simultaneously restore movement and the sense of touch. The BCI essentially consists of 3 components: 1) an interface implanted on the outer layer of the brain that records electrical brain activity / ‘thoughts’; 2) a computer that leverages machine learning to detect specific ‘thoughts’ in real-time (e.g., I want to grab that mug); and 3) a device or devices that translate a ‘thought’ into an action (e.g., stimulation of arm muscles to move the hand and grab a mug). In our group’s recent BCI work, we have now shown the ability to also restore the sense of touch in a human participant with a severe spinal cord injury. The BCI accomplishes this by detecting touch that the participant cannot feel, and boosts it into conscious perception using artificial sensory feedback. The presentation will also cover BCI technology at large, new algorithms for brain activity decoding, and future brain interfaces that may not require surgery. Video
20200701 July 1, 2020 Open
20200708 July 8, 2020
ZOOM ONLY: Cooperative Conservation and the Recovery of the Endangered Island Fox
Tim Coonan, National Park Service (ret.) Chris Stoughton Island foxes exist at small population sizes on California’s eight Channel Islands, and their island evolution makes them vulnerable to novel diseases, parasites and predators. In the 1990s island foxes declined to near extinction on the northern Channel Islands due to predation by golden eagles and on Santa Catalina Island due to canine distemper virus. Island foxes were listed as Endangered in 2004, and became the subjects of intense recovery actions, including captive breeding and reintroduction, capture and relocation of golden eagles, and vaccination against canine distemper virus and rabies. Foxes recovered and were delisted in 2016, marking the quickest recovery of a mammal in the history of the ESA. Recovery required expertise from such disciplines as raptor biology, ecology, disease/veterinary, genetics, animal husbandry and population demography. Work was coordinated through a novel model of cooperative conservation well ahead of the official effort to list and recover an endangered species. Video
20200715 July 15, 2020 Open
20200722 July 22, 2020 Open
20200729 July 29, 2020 Open
20200805 Aug. 5, 2020 Open
20200812 Aug. 12, 2020 Open
20200819 Aug. 19, 2020 Open
20200826 Aug. 26, 2020
Helping America’s Vanishing Birds in a Changing Environment
Dr. Nigella Hillgarth, Center for Ecosystem Sentinels, University of Washington Chris Stoughton Bird populations are declining in North America. In the past fifty years over three billion birds have disappeared from the landscape.  That is an average decline of 29%. This talk addresses the reasons behind the decline and how we can save our bird populations.  Many of our most familiar yard birds such as sparrows, warblers, finches and swallows are among those most threatened by ecosystem disruption through loss of habitat, pollution and climate change. Although this is a serious problem for wildlife in general there are ways in which we can mitigate this damage and this talk address some of the ways individuals can help their local bird populations as well as at a national level. Video
20200902 Sept. 2, 2020 Open
20200909 Sept. 9, 2020 Open
20200916 Sept. 16, 2020 Elucidating the nature of neutrinos: the state-of-the art in searches for neutrinoless double beta decay Laura Baudis Patrick Fox Neutrinos are the only known elementary particles that are Majorana fermion candidates, implying that they would be their own antiparticles. The most sensitive and perhaps only practical probe of the Majorana nature of neutrinos is an extremely rare nuclear decay process, the double beta decay without the emission of neutrinos. After an introduction to the physics of neutrinoless double beta decay, I will present the experimental techniques to search for this exceedingly rare process. I will show the latest results from leading experiments in the field, then discuss future projects and their prospects to probe the inverted neutrino mass ordering scenario. Video
20200923 Sept. 23, 2020 Open
20200930 Sept. 30, 2020
The Future is Open: Adventures with Public Collider Data
Jesse Thaler, MIT Pushpa Bhat In November 2014, the CMS experiment at the Large Hadron Collider made the unprecedented move of releasing research-grade particle physics data for unrestricted use. I am a theoretical particle physicist, and for the first time, I had access to real collision data from a cutting-edge experiment, as well as an opportunity to demonstrate the scientific value of public data access. Over the past six years, my research group has carried out a number of innovative analyses using the CMS Open Data. In this colloquium, I highlight some of our research successes as well as some of the challenges we faced using public collider data to explore physics in and beyond the Standard Model. Video
20201007 Oct. 7, 2020 ZOOM ONLY: Title: Dark Matter: A Cosmological Perspective Katie Mack, North Carolina State University Dan Hooper While it is considered to be one of the most promising hints of new physics beyond the Standard Model, dark matter is as-yet known only through its gravitational influence on astronomical and cosmological observables. I will discuss our current best evidence for dark matter's existence as well as the constraints that astrophysical probes can place on its properties, while highlighting some tantalizing anomalies that could indicate non-gravitational dark matter interactions. Future observations, along with synergies between astrophysical and experimental searches, have the potential to illuminate dark matter's fundamental nature and its influence on the evolution of matter in the cosmos from the first stars and galaxies to today. Video
20201014 Oct. 14, 2020 Open
20201021 Oct. 21, 2020 From Quantum Mechanics to Spacetime Sean Carroll, Caltech Chris Stoughton Nine decades in, the foundations of quantum mechanics remain mysterious. Meanwhile, modern physicists puzzle over how to reconcile quantum mechanics with gravity. I will suggest that these problems are related, and that a promising strategy suggests itself: rather than "quantizing gravity," we should look for gravity within quantum mechanics. This approach has interesting consequences for how we think about the nature of space and time. Video
20201028 Oct. 28, 2020
SPECIAL TIME: Computational Prediction of Superconducting and Superhard Materials
Professor Eva Zurek, University at Buffalo, SUNY Chris Stoughton High pressure opens the door towards the synthesis of materials with unique properties, e.g. superconductivity, hydrogen storage media, high energy density and superhard materials. Under pressure elements that would not normally combine may form stable compounds or they may mix in novel proportions. As a result, we cannot use our chemical intuition developed at 1 atmosphere to predict phases that become stable when compressed. To facilitate the prediction of the crystal structures of novel materials, without any experimental information, we have developed the XtalOpt evolutionary algorithm for crystal structure prediction. XtalOpt has been applied to predict the structures of unique hydrides that become stable at pressures attainable in diamond anvil cells. The electronic structure and propensity for high-temperature superconductivity of these phases is analyzed via quantum-mechanics based calculations. We also describe the recent extension of XtalOpt towards the prediction of superhard materials, and the computational discovery of 43 superhard phases of carbon. Video
20201104 Nov. 4, 2020 Open
20201111 Nov. 11, 2020 Open
20201118 Nov. 18, 2020
Gravitational Test beyond the First Post-Newtonian Order with the EHT
Lia Medeiros, Institute for Advanced Study Chris Stoughton Our current understanding of black holes assumes that they are described by the Kerr solution to Einstein’s equations. On April 10, 2019, the Event Horizon Telescope (EHT), released the first image of a black hole resolved to event horizon scales and the first measurement of the size of a black-hole shadow. In October of 2020 we published a new test of general relativity at the 2PN order based on this measurement. I will discuss how we can use the Event Horizon Telescope to test the Kerr nature of black holes, both with this first image and in the future. Video
20201125 Nov. 25, 2020 No colloquium
20201202 Dec. 2, 2020 Open
20201209 Dec. 9, 2020 Open
20201216 Dec. 16, 2020
CANCELLED: Planetary Systems Biochemistry: Inferring the “Laws of Life” at a Planetary Scale
Sara Imari Walker, PhD, Arizona State University Dan Hooper In 1943 Schrodinger famously delivered a set of lectures aiming to tackle the question “What is Life?” from the first-principles approach of a theoretical physicist. Over 70 years later, we’ve still made little headway in coming up with a general theory for what life is. While many definitions for life do exist, these are primarily descriptive, not predictive, and they have so far proved insufficient to explain the origins of life from non-living matter, or to provide rigorous constraints on what properties are universal to all life, even that on other worlds. Yet, as we set our sights on life detection as a goal of upcoming robotic missions and space observatories, more rigorous understanding of the universal properties of living matter are becoming increasingly vital to uncover. Here I discuss approaches to identify what universal principles might underlie living matter based on studying biochemical networks on Earth from the scale of individual organisms to the planetary scale.
20201223 Dec. 23, 2020 No colloquium
20201230 Dec. 30, 2020 No colloquium