Events at Physics |
Events During the Week of March 1st through March 8th, 2020
Monday, March 2nd, 2020
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Alice In-Between Worlds: The Wonderland of Dusty Plasma
- Time: 12:05 pm - 12:55 pm
- Place: 2241 Chamberlin Hall
- Speaker: Eva Kostadinova, Baylor University, Center for Astrophysics Space Physics and Engineering Research (CASPER)
- Abstract: "Why, sometimes I've believed as many as six impossible things before breakfast."
~Lewis Carroll. Alice in Wonderland.
Order and stability in the giant world of stars and galaxies is dominated by the force of gravity. In contrast, the tiny world of atomic and subatomic particles is held together by nuclear and quantum forces. As one sizes up from the subatomic to the astronomical scales, a natural question emerges: What universal principles govern the world of the “in-between”? What happens to the laws of nature when the time and spatial scales change from large to small? In this talk, I invite you to a journey through the mesoscopic wonderland of dusty plasma, where principles are semi-classical, forces are non-linear, thermodynamics is non-equilibrium, and dimensions are quasi-defined. We will tour this almost impossible world by exploring dusty plasmas across scales, in nature and laboratory, both on Earth and in space.
- Host: Jan Egedal
Tuesday, March 3rd, 2020
- Chaos & Complex Systems Seminar
- The complexities of conveying hurricane forecast uncertainty to the public
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Derrick Herndon, Space Science and Engineering Center
- Abstract: Tropical Cyclones (Hurricanes) are one of the most violent and dynamic storms on our planet. Each year an average of 80 tropical cyclones develop over the warm tropical oceans. Most of these storms spin harmlessly at sea. Others bring extreme winds, torrential rainfall and surges from the ocean ashore to devastating effect. Significant progress has been made in our ability to forecast the development and track of these storms over the last few decades. However, substantial challenges remain. Our ability to forecast the internal dynamics that drive the changes in storm intensity have not quite kept pace with other aspects of the forecast problem. Providing accurate and meaningful forecast information for an inherently chaotic system to the public is also a continuing challenge. This talk will explore recent advances in our understanding of these storms along with some remaining challenges related to the complex interactions between people and hurricanes.
- Host: Clint Sprott
Wednesday, March 4th, 2020
- No events scheduled
Thursday, March 5th, 2020
- Cosmology Journal Club
- Time: 12:00 pm - 1:00 pm
- Place: 5242 Chamberlin Hall
- Abstract: We discuss papers from arxiv.org related to cosmology each week. All are welcome and feel free to bring your lunch. If there is a paper you would like to present, or have questions or comments, please email Ross Cawthon (cawthon@wisc.edu) and Santanu Das (sdas33@wisc.edu).
- Astronomy Colloquium
- COLLOQUIUM CANCELLED: The Experiment for Cryogenic Large-aperture Intensity Mapping (EXCLAIM)
- Time: 3:30 pm - 4:30 am
- Place: 4421 Sterling Hall
- Speaker: Dr. Eric Switzer , NASA/Goddard
- Abstract: CANCELLED BECAUSE OF NEW NASA TRAVEL REGULATIONS REGARDING COVID-19 VIRUS. RESCHEDULED FOR NOVEMBER 6. The EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) is a cryogenic balloon-borne instrument that will survey galaxy and star formation history over cosmological time scales. Rather than identifying individual objects, EXCLAIM will be a pathfinder to demonstrate an intensity mapping approach, which measures the cumulative redshifted line emission. EXCLAIM will operate at 420-540 GHz with a spectral resolution R=512 to measure the integrated CO and [CII] in redshift windows spanning 0 < z < 3.5. CO and [CII] line emissions are key tracers of the gas phases in the interstellar medium involved in star-formation processes. EXCLAIM will shed light on questions such as why the star formation rate declines at z < 2, despite continued clustering of the dark matter. The instrument will employ an array of six superconducting integrated grating-analog spectrometers (micro-spec) coupled to microwave kinetic inductance detectors (MKIDs). I will present an overview of the EXCLAIM instrument design and status.
- Host: Timbie
Friday, March 6th, 2020
- Professional Development Seminar
- Vroom Vroom How to Make Your Code Fast
- Time: 2:30 pm - 3:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Rob Morgan, Physics PhD Graduate Student
- Abstract: Knowing how to write efficient code can make your life much easier, but also will make you a more attractive job candidate. We’ll discuss what makes code slow, how to profile your code, parallelization, and modules for speeding up your workflow.
- Host: Rob Morgan, graduate student
- Physics Department Colloquium
- Advances in Understanding Relativistic Plasma Turbulence
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall
- Speaker: Vladimir Zhdankin, Princeton
- Abstract: Many distant high-energy astrophysical systems (such as pulsar wind nebulae, black-hole accretion flows, and jets from active galactic nuclei) contain collisionless plasmas that are relativistic, radiative, and highly nonthermal. Understanding the nature of turbulence in this extreme plasma physical regime and its implications for observations is an outstanding challenge in plasma astrophysics. Particle-in-cell (PIC) simulations have recently opened this topic to detailed, first-principles numerical and theoretical scrutiny. I will describe the latest progress on understanding relativistic kinetic turbulence. PIC simulations have demonstrated that relativistic turbulence is an efficient particle accelerator, joining the ranks of shocks and magnetic reconnection as a viable source of high-energy particles (and thus broadband radiation and cosmic rays). These simulations are now giving long-awaited tests for a line of analytic theories of stochastic particle acceleration originating with Enrico Fermi in 1949. Relativistic PIC simulations are also giving new insights into two-temperature electron-ion plasmas and radiative turbulence. The next several years promise to bring new breakthroughs into these problems.
- Host: Jan Egedal