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Colloquium

Effective Fall 2021, unless stated otherwise, we are back to holding our colloquia in person. All physics and astronomy colloquia will take place on  Thursday afternoon  from  4 to 5 pm  in room 4327 Stevenson Center, but we will also have a hybrid Zoom option available for those who would prefer to attend remotely

For details please contact Ashley E. Brammer by email (ashley.e.brammer@vanderbilt.edu) or phone (615-343-7389).

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Fall 2021

Thursday September 9th 2021 4:00 PM

Karin Oberg, Center for Astrophysics | Harvard-Smithsonian

The Chemistry of Planet Formation   (show abstract)

The past decades have revealed that planets are incredibly common in our Galaxy. Among this wealth of exoplanets there is an especially interesting subset: temperate, rocky planets that may be suitable for life. What are the likelihood that such planets contain water and the building blocks of a life, i.e. that they are chemically habitable? These questions can be addressed by considering the chemical environment within which planets assemble. Planets assemble in disks of dust and gas around young stars. Thanks to the exquisite capabilities of ALMA we can directly observe these disks at high spatial resolution, catching planet formation in action, and map out the chemistry that characterizes them. I will present some of our latest discoveries on what the chemistry of these disks are, how they are shaping the outcome of planet formation, and what they teach us about the chemical habitability of mature planetary systems.

Host: R. Sherrer

Thursday September 16th 2021 4:00 PM

GUY and REBECCA FORMAN LECTURE

Julia Kregenow, Teaching Professor, Penn State University

Connecting with your Students: Meet them Where They Are   (show abstract)

Meeting students where they are is a collaborative endeavor between student and instructor. An instructor should first find out where their students are in their preparation, be explicit about where you want your course to take them, and then take purposeful steps to design your instruction to help them make that journey. Different students start out in different places, so I will share strategies for engaging and supporting students with different levels of preparation. Furthermore, I will discuss strategies to help motivate students to embrace their portion of that responsibility. I will also describe and demonstrate a variety of ways to use active learning both to help students learn more deeply, and also to gather frequent feedback from your students so you can monitor where they are in their learning. This feedback will help you plan and pitch your instruction at an appropriate level, and will also empower your students to monitor and take more ownership of their own learning.

Host: S. Hutson

Thursday September 23rd 2021 4:00 PM

William R. Holmes, Department of Physics and Astronomy, Vanderbilt University

Modeling intra-cellular insulin dynamics in pancreatic Beta cells   (show abstract)

In this talk, I will discuss the role of cytoskeletal-mediated transport (by microtubules in particular) in regulating insulin dynamics in pancreatic cells. Due to the increasingly prevalence of diabetes and related disorders, understanding how individual cells regulate insulin availability and secretion in response to glucose stimulation is of utmost importance. In this talk, I will focus on the intra-cellular (rather than systemic) dynamics of insulin granules and will discuss a collection of joint modeling and experimental investigations aimed at better understanding those dynamics. First, I will use computational modeling to investigate how transport influences the spatial localization, and hence availability (for exocytosis) of those granules. Second, I will discuss our efforts to understand how the tracks along which transport occurs (microtubules) are built. Finally, in light of the observation that insulin motions are strongly anomalous (e.g. not standard diffusion), I will discuss some strange, previously un-observed theoretical consequences of anomalous (Generalized Langevin in particular) particle dynamics.

Host: S. Hutson

Thursday September 30th 2021 4:00 PM

ALICE CLAIR HANKLA LECTURE

Katie Mack, NC State University

Dark Matter: A Cosmological Perspective   (show abstract)

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.

Host:S. Hutson

Thursday October 7th 2021 4:00 PM

Alfredo Gurrola, Vanderbilt University

Unprecedented searches for new particles at the Large Hadron Collider   (show abstract)

Everything in our universe is made from building blocks called fundamental particles, which are governed by four fundamental forces. Our best understanding of how particles and forces are related to each other is encapsulated in a frame-work referred to as the Standard Model (SM) of particle physics. However, the SM remains incomplete. It fails to provide a particle candidate for astronomical dark matter, does not provide an explanation for the mass of light neutrinos, and makes several predictions that are in disagreement with recent precision measurements. There are a multitude of theoretical models incorporating additional interactions to address these shortcomings of the SM. The implication of these models is the manifestation of new particles that can be probed in high-energy proton-proton collisions at the Large Hadron Collider (LHC). Numerous ideas have been proposed to probe beyond-the-Standard Model (BSM) physics scenarios, motivating a large volume of searches at the LHC. Nonetheless, searches so far have failed to show any sign of new physics, thus remaining concealed in processes not yet investigated. This talk will focus on novel, state-of-the-art ideas and strategies to explore un-investigated territory where new physics may lie. Focus will be placed on the role Vanderbilt has played in the search for new physics and the role it will play in the years to follow. In doing so, the ideas and strategies behind the searches, channels considered, and the experimental techniques used at the LHC will be outlined.

Host:S. Hutson

Thursday October 14th 2021 4:00 PM

Zeljko Ivezic, Department of Astronomy, University of Washington

The Greatest Movie of All Time   (show abstract)

The Legacy Survey of Space and Time (LSST), the first project to be undertaken at the new Vera C. Rubin Observatory, will be the most comprehensive optical astronomical sky survey ever undertaken. Starting in a few years, Rubin Observatory will obtain panoramic images covering the sky visible from its location in Chile every clear night for ten years. Close to a thousand observations of each position across half of the celestial sphere will represent the greatest movie of all time: it would take 11 months of uninterrupted viewing to see it. About 20 billion galaxies and a similar number of stars will be detected using this 60 petabyte image dataset — for the first time in history, the number of cataloged celestial objects will exceed the number of living people. LSST data will be used for investigations ranging from cataloging dangerous near-Earth asteroids to fundamental physics such as characterization of dark matter and dark energy. I will briefly describe scientific goals behind this project, show lots of pretty pictures to illustrate the progress of its construction, and finish with a discussion of data analysis challenges that need to be tackled to make the best use of LSST data.

Host: J. Runnoe

Thursday October 21st 2021 4:00 PM

Jorge Moreno, Pomona College

Galaxies lacking dark matter in the standard cosmological paradigm   (show abstract)

The standard LCDM model predicts that galaxies form within dark matter halos and that low-mass galaxies are more dark-matter dominated than massive ones. The unexpected discovery of two low-mass galaxies lacking dark matter immediately provoked concerns about the standard cosmology and ignited explorations of alternatives, including self-interacting dark matter and modified gravity. Apprehension grew after several cosmological simulations using the conventional model failed to adequately form numerical analogs (with comparable internal characteristics: stellar-masses, sizes, velocity dispersions and morphologies). In this talk I will show that the standard paradigm naturally produces galaxies lacking dark matter with internal characteristics in agreement with observations. Using a state-of-the-art cosmological simulation with the FIRE-2 physics model and a meticulous galaxy-identification technique, we find that extreme close-encounters with massive neighbors can be responsible for this. We predict that ∼ 30% of massive central galaxies (with at least 1e11 solar masses in stars) harbor at least one dark-matter deficient satellite (with 1e8 – 1e9 solar masses in stars). This distinctive class of galaxies opens an additional layer to our understanding of the role of interactions in shaping galactic properties. Future observations surveying galaxies in the aforementioned regime will provide a crucial test of this scenario.

Host: J. Runnoe

Thursday October 28th 2021 4:00 PM

Tanmay Vachaspati, Arizona State University

Is the Universe magnetized?   (show abstract)

The search for cosmological magnetic fields has provided tantalizing hints that the universe was magnetized even at its very early stages, suggesting a particle physics origin for magnetic fields. Concurrently, the standard electroweak model of particle physics is known to contain confined magnetic monopoles that can potentially source the magnetic fields. I will describe some of the observational results together with our current understanding of electroweak magnetic monopoles, and the need for additional charge-parity (CP) violation in particle physics to explain observations. Reference: Progress on Cosmological Magnetic Fields, T. Vachaspati, Rept.Prog. Phys. 84 (2021) 7, 074901. arXiv:2010.10525.

Host: R. Scherrer

Thursday November 4th 2021 4:00 PM

Albert-Laszlo Barabási, Network Science Institute and Department of Physica, Northeastern University, Division of Network Medicine, Harvard University, Department of Network and Data Science, Central European University

Network Science: From structure to control   (show abstract)

Systems as diverse as the world wide web, Internet or the cell are described by highly interconnected networks with amazingly complex topology. A key discovery of network science is the realization that real networks emerge and evolve following self-organizing processes governed by simple but generic laws, resulting in architectural features that makes them much more similar to each other than one would have expected by chance. I will discuss the order characterizing our interconnected world and its implications to network control. Indeed, the ultimate proof of our understanding of biological systems is reflected in our ability to control them. We therefore developed analytical tools to study the controllability of an arbitrary complex directed network, identifying the set of driver nodes whose time-dependent control can guide the system’s entire dynamics. Finally, I will discuss falsifiable experimental evidence of controllability in neural networks.

Host: S. Hutson

Thursday November 11th 2021 4:00 PM

Lam Hui, Department of Physics, Columbia University

Wave dark matter   (show abstract)

We will discuss the possibility that dark matter is composed of sufficiently light particles that it effectively behaves as a collection of waves. We will review the particle physics motivations and the rich wave phenomenology, and discuss the implications for astronomical observations and experimental detection.

Host: R. Scherrer

Thursday November 18th 2021 4:00 PM

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Thursday December 2nd 2021 4:00 PM

Mike Brotherton, University of Wyoming

Science Outreach through Science Fiction   (show abstract)

For better or worse, the public absorbs information through the entertainment they consume. In the ideal case, science fiction with accurate science can serve as a vector of stealth education and help inspire the next generation of scientists. Astronomy professor and science fiction author Mike Brotherton writes scientifically accurate novels and stories, edits anthologies, and speaks at science fiction conventions toward these end goals. He also founded the highly successful Launch Pad Astronomy Workshop for Writers, which has over 200 alumni now with a collective audience numbering in the millions, and has inspired similar efforts in quantum physics. Innovative methods of public outreach like these can produce powerful broader impacts of the type valued by the National Science Foundation and NASA, both of whom have funded Launch Pad in the past.

Host: J. Runnoe

Thursday December 9th 2021 4:00 PM

Ricardo Ruiz, Lawrence Berkeley National Laboratory

Using Soft-Matter Physics for Nanopatterning   (show abstract)

Macromolecular self-assembly has evolved to become an important and valuable tool for bottom-up patterning and fabrication at the nanometer scale. From block copolymer lithography to nanocrystal superlattices to biomolecular assemblies, bottom-up patterning is reaching an unprecedent level of control over complex patterns at the nanoscale with an increasing degree of precision. There is no question that the lithographic landscape has been transformed in the past few years with the introduction of extreme ultraviolet (EUV) lithography and the maturity of multiple patterning techniques. At dimensions below 10 nm, emphasis is shifting away from resolution to precision, highlighting the importance of the uniformity achieved by block copolymers and the exquisite precision afforded by biomolecular assemblies. Moreover, an opportunity may be opening for new, higher complexity, information-rich architectures where hybrid nanoparticle-(bio)molecule assemblies may shine. With features defined at the molecular level and the potential to modular and hierarchical structures, the thermodynamics and kinetic landscape of these self-assembling systems offers a path to unique 2D and 3D architectures. In this talk I will review the current state of bottom-up patterning with soft matter and I will discuss research plans at The Molecular Foundry related to molecular-scale assembly.

Host: R. Haglund

Spring 2022

Thursday January 13th 2022 4:00 PM

RESERVED

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Thursday January 20th 2022 4:00 PM

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Thursday January 27th 2022 4:00 PM

Karan Jani, Department of Physics and Astronomy, Vanderbilt University

Finding Black Holes That Should Not Exist: From Earth, Space and Moon   (show abstract)

Recent gravitational-wave observations from LIGO have confirmed a previously unknown population of black holes of 100 solar masses. These sources challenge our sacred ideas of stellar evolution while providing the most concrete evidence for the elusive intermediate-mass black holes (IMBHs: 100 to 10,000 solar masses). In this talk, I will review what we can learn about IMBHs this decade with LIGO and DOE/NSF-funded gravitational-wave network on the Earth. In doing so, I would briefly highlight the Vanderbilt-LIGO partnership on this front, which has led to new thermodynamical insights on black holes. For the upcoming NASA-led space mission LISA, I would describe a new method of 'Multi-band Astrophysics' for probing General Relativity and origins of IMBHs. I would conclude by making a case for Dark Energy and cosmological survey of IMBHs as the major fundamental science drivers for humanity's return to the Moon, and Vanderbilt's leadership on this front.

Host: R. Scherrer

Thursday February 3rd 2022 4:00 PM

Austin Baty, Rice University

Trillion Degree Matter: Probing the Emergence of the Quark-Gluon Plasma   (show abstract)

Using high-energy nucleus-nucleus collisions, physicists are able to study the trillion-degree soup of quarks and gluons that existed in the very early universe. This strongly-interacting matter, known as the quark-gluon plasma, exhibits unique properties including the suppression of high-momentum particle production and behavior as a ‘nearly-perfect’ fluid. Surprisingly, some of these signals have also been observed in smaller systems, such as proton-proton collisions, prompting questions about the minimum conditions needed to observe such phenomena. I will describe my experimental efforts to clarify this issue using recent lead-lead collision data from the CMS detector at the LHC, as well as archived data from previous particle colliders. In addition, I will discuss exciting opportunities for the future at both the LHC and RHIC, which will usher in a new era of understanding regarding strongly interacting matter.

Host: J. Velkovska

Thursday February 10th 2022 4:00 PM

James Mulligan, University of California, Berkelely

The quark-gluon plasma: emergent behaviors of the strong nuclear force   (show abstract)

While the Lagrangian of quantum chromodynamics is a known part of the Standard Model of particle physics, its resulting equations of motion can only be solved in certain regimes. This leaves our understanding of the emergent behaviors of the strong force limited: What are the dynamics that confine quarks and gluons into hadrons, generating nearly all the mass in the visible universe? I will present experimental measurements of high-energy nuclear collisions at the Large Hadron Collider, where we form droplets of deconfined quarks and gluons known as the quark-gluon plasma. I will discuss efforts to reveal the nature of the quark-gluon plasma from these measurements using Bayesian inference, and prospects to simulate the dynamics of confinement using quantum computers.

Host: J. Velkovska

Thursday February 17th 2022 4:00 PM

Jing Wang, Massachusetts Institute of Technology

Tasting the Hot Quark Soup with Heavy Quarks   (show abstract)

Quantum Chromodynamics (QCD) predicts a deconfined state of quarks and gluons: Quark Gluon Plasma (QGP). This extremely hot and dense matter is believed to exist in the early universe and can be reproduced in relativistic heavy-ion collisions. Studying the in-medium color force will greatly deepen our understanding of the strong interaction. Heavy quarks created in the collisions are golden probes of the QGP and provide unique insights into the in-medium energy loss, diffusion coefficient, and hadronization mechanism. Compared to the ordinary mesons and baryons, the exotic hadron X(3872) consisting of 4 valence quarks will experience stronger medium induced modification of hadronization. Moreover, the QGP opens new opportunities to the study of the nature of X(3872). The structure of X(3872) discovered about 20 years ago is still not fully understood, and studying X(3872) in heavy-ion collisions may solve this problem as different proposed states are expected to interact differently with the medium. In this talk, I will review the studies of heavy-flavor hadrons with the data collected by the CMS detector at the Large Hadron Collider and report the first measurement of X(3872) in heavy-ion collisions. I will also discuss the opportunities in the CMS and the sPHENIX experiment in the near future with higher luminosity and further upgraded detectors.

Host: J. Velkovska

Monday February 21st 2022 4:00 PM

Raghav Kunnawalkam Elayavalli, Yale University

Unravelling the space-time evolution of quarks and gluons    (show abstract)

Collider experiments have proven themselves immensely useful in studying quarks and gluons (collectively partons) via jets - the collimated clusters of particles resulting from parton fragmentation. The last few years in particular have seen a push towards the study of fundamental QCD and jet substructure via innovative techniques to experimentally access the multi-scale evolution of the jet's shower. In this talk, I start by highlighting recent STAR measurements that observed an inherent correlation between the angular and momentum scales within a jet and more importantly, constitute the first direct observation of variation in the shower kinematics later in time along the jet evolution. We then discuss jets in heavy ion collisions, wherein an emergent state of unbound colored matter called the quark-gluon plasma (QGP), impedes and quenches the jet energy. I provide a roadmap from my current studies at STAR to the next-generation jet measurements at the new sPHENIX detector at RHIC with the goal of extracting QGP's microscopic transport properties and mapping its space-time evolution. Finally, I cover the impact of the upcoming Electron Ion Collider where these novel jet techniques and experimental precision lead to multi-dimensional imaging of both the perturbative and non-perturbative regimes within jets, allowing us unprecedented access into color confinement and hadronization.

Host: J. Velkovska

Thursday February 24th 2022 4:00 PM

Yi Chen, Massachusetts Institute of Technology

Quarks, gluons, plasma, and exciting phenomena in ultrarelativistic heavy-ion colliders   (show abstract)

Quarks and gluons are fundamental building blocks of matter. They are usually confined in a tiny nucleus in an atom and bound by the strong force, one of the fundamental forces of nature. It is orders of magnitudes stronger than all the other fundamental forces. However, under extreme conditions, such as those right after the big bang, the temperature and density are high enough that an exotic state of matter, the quark-gluon plasma, can be formed. In this state, quarks and gluons can move without being confined in a nucleus. Through ultrarelativistic heavy-ion colliders like the Relativistic Heavy-Ion Collider (RHIC) or the Large Hadron Collider (LHC), we now have a controlled way to produce tiny droplets of it in an experiment consistently! They are a natural mini-laboratory to study the plasma droplet and test the theory of strong interaction (quantum chromodynamics, QCD) under extreme conditions. Many fascinating new phenomena are observed. For example, there is the "jet quenching" phenomenon, where high energy quarks and gluons (a few orders of magnitudes higher than the plasma temperature) are seen to lose a significant amount of energy while interacting with the plasma. I will discuss the exciting developments in our understanding of the jet quenching phenomenon and the quark-gluon plasma in recent years and what we might expect in the near future.

Host: J. Velkovska

Thursday March 3rd 2022 4:00 PM

John W. Conklin, University of Florida

Gravity as an Observable: Tracking Climate Change and the Nature of our Universe   (show abstract)

Precise measurements of gravity made from space can provide valuable information about our changing climate and astrophysical events in our Universe that drive its evolution. Current and future satellite geodesy missions track mass transport over the surface of the Earth due to changes in underground water storage, the amount of water in large lakes and rivers, soil moisture, ice sheets and glaciers, and sea levels. Gravitational wave observation represents an entirely new way of observing our universe and therefore provides enormous potential for scientific discovery. The first direct detections in 2016 by the ground-based LIGO observatory has already brought new insights into the population of black holes and the evolution of our Universe. The Gravity Recovery And Climate Experiment (GRACE) and the subsequent GRACE Follow-On mission precisely track the variations in the separation distance between two Earth-orbiting spacecraft to estimate the Earth’s mass distribution and how it changes on monthly time-scales. Precision inertial sensors on each spacecraft are needed to separate spacecraft motion due to atmospheric drag and solar radiation pressure from the relative motion due to Earth’s gravity. The Laser Interferometer Space Antenna (LISA), a joint venture between NASA and the European Space Agency, will be the first mission to detect and observe low-frequency gravitational waves from space, complementing observatories on the ground. LISA will consist of three Sun-orbiting spacecraft that form an equilateral triangle, with each side measuring 2.5 million kilometers in length. Each spacecraft houses two free-floating test masses (TM), which are protected from all disturbing forces so that they follow pure geodesics in spacetime. Laser interferometry is used to measure the minute variations in the distance, or light-travel time, between these purely free-falling TMs, caused by gravitational waves. This talk will describe the precision inertial sensing research at the University of Florida Precision Space Systems Lab and the resulting technology that will be used in future Earth geodesy missions and in LISA.

Host:K. Holley-Bockelmann

Thursday March 10th 2022 4:00 PM

SPRING BREAK-NO COLLOQUIUM

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Thursday March 17th 2022 4:00 PM

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Thursday March 24th 2022 4:00 PM

Joseph Hamilton, Department of Physics and Astronomy, Vanderbilt University

64 Years in Physics at Vanderbilt, The Road Less Traveled   (show abstract)

An overview of my 64 years on the Physics faculty will be given beginning with how I arrived at Vanderbilt. There will be highlights of my career in both teaching and research. Beginning with teaching, I will note the importance of demonstrations especially for the over 10,000 non science majors I have taught. Descriptions of my developments of the UNISOR consortium of 10 universities and the Joint Institute for Heavy Ion Research at Oak Ridge National Laboratory and how these helped transform ORNL, will be made. Then important research discoveries will be presented including the first evidence for E0 radiations predicted by the Bohr Mottelson Nuclear Model and the first major failure of the Model; changing the paradigm from each nucleus having one fixed shape to nuclei across the periodic table having coexistence of different nuclear shapes; the first evidence of super deformed nuclear ground states; the origin of shape coexistence in Se and Kr nuclei; the first Coulomb excitation of an actinide nucleus with lead ions, and the discovery of 3 new elements in the periodic table, my leading in the discovery of new element 117 and naming it for the State of Tennessee.Finally, a brief overview will be given of over 15 new facilities in 11 countries (3 in US) for low energy nuclear physics at costs from several $100M to over $1B to be completed by 2025. I shall be telling this with a sigh Somewhere ages and ages hence: Two roads diverged in a yellow wood, and I- I took the one less traveled by And that has made all the difference. Robert Frost

Host: S. Hutson

Thursday March 31st 2022 4:00 PM

Mallory Molina, Ford Postdoctoral Fellow at Montana State University

The Origins and Growth of Black Holes   (show abstract)

While supermassive black holes live in the heart of almost every massive galaxy, their origins remain unknown. Massive black holes residing in much smaller dwarf galaxies can shed light on the formation and evolution of supermassive black holes, but are notoriously difficult to detect. In this talk, I will present a new technique I have developed to find black holes in dwarf galaxies using highly energetic coronal-line emission. This method provides a new pathway to find black holes that are often missed by traditional optical detection techniques. I will also discuss my work on how black holes grow over time, including how black holes merge and interact with their host galaxies. I will then describe my future directions, including my plans to work with the James Webb Space Telescope (JWST) and Laser Interferometer Space Antenna (LISA). Finally, I will briefly discuss my work related to diversity, equity and inclusion and my plans to continue this work at Vanderbilt.

Hosts: J. Runnoe and S. Hutson

Thursday April 7th 2022 4:00 PM

Marina Kounkel, Department of Physics and Astronomy, Vanderbilt University

Dynamical zoo of star formation   (show abstract)

The era of Gaia has brought in a revolution in understanding how star forming complexes form and evolve over time. It is now possible to assemble a comprehensive census of members of young associations spanning all ages, and to not only compare younger populations with their more evolved counterparts, but also to directly observe their current dynamical state. This makes it possible to make a model of their 3d structure, to determine what physical processes were responsible for shaping their morphology, as well as to analyze their eventual fate. I will present an overview of some of the efforts of disentangling the star forming history in some of the individual nearby associations as well as in the Solar Neighborhood as a whole.

Host: S. Hutson

Thursday April 14th 2022 4:00 PM

Saul Teukolsky, Cornell University

Testing the No-Hair Theorem and the Area Theorem with LIGO   (show abstract)

One of the key results of general relativity is that an astrophysical black hole in equilibrium is uniquely described by just two parameters, its mass and spin. This is called the No-Hair Theorem, a result that is not true in alternative theories of gravity. For many years, people have speculated about testing the theorem using gravitational waves from merging black holes. For a long time, the consensus has been that this test will require the sensitivity of next-generation detectors. I will show that this consensus is wrong for a surprising reason, and report a test with data from GW150914, the first LIGO gravitational wave detection. An extension of the test confirms Hawking's Area Theorem at the 97% limit.

Host: R. Scherrer

Thursday April 21st 2022 4:00 PM

Leigh Orf, The Cooperative Institute for Meteorological Studies, University of Wisconsin

Simulation and Visualization of the World's Most Powerful Thunderstorms    (show abstract)

Supercell thunderstorms are prolific producers of damaging tornadoes, some of which are powerful and long-lived. While forecasters have become much better and predicting days in advance the broad regions over which storms will occur, our ability to forecast the details of supercell behavior (such as tornado strength and track) 2 hours to 30 minutes in advance remains elusive. The recent tornado outbreaks in the southern United States and resultant fatalities underscore the need for better tornado forecasts. A critical first step to this end is understanding how tornadoes form and evolve within their parent storm. This talk will cover some meteorological background as well as the logistical issues associated with successfully executing machine-wide massively parallel supercell thunderstorm simulations and analyzing the resulting data. Results from large eddy simulations of supercell thunderstorms containing tornadoes will be presented, along with simulations focusing on the anvil region of the cloud that is visible to orbiting meteorological satellites. Features discussed will include the streamwise vorticity current, a near-ground feature found to be associated with tornadogenesis and maintenance in some supercells, as well as above anvil cirrus plumes, cloud-top features found to be associated with severe weather on the ground, and forced by hydraulic jumps forming downwind of the overshooting thunderstorm top.

Host: A. Dodson