Events at Physics |
Events During the Week of April 28th through May 5th, 2019
Monday, April 29th, 2019
- Plasma Physics (Physics/ECE/NE 922) Seminar
- SPARC and the high-field, privately-funded path to fusion energy
- Time: 12:05 pm
- Place: 2241 Chamberlin Hall
- Speaker: Martin Greenwald, MIT
- Abstract: While fusion has enormous potential as a source of safe, carbon-free power, the current road map seems unlikely to deliver this new energy source in time to help with efforts to mitigate global warming. However, the basis for a breakthrough is here. High-temperature superconductors have emerged from the laboratory into industrial maturity – permitting the construction of smaller, cheaper fusion devices. With the SPARC project, MIT has embarked on a project to test this premise by building a deuterium-tritium burning, mid-sized tokamak – of a size similar to many machines already in operation. Using well-known physics to project performance, we expect SPARC to produce 50-100 MW of fusion power, comfortably more than the 30 MW required to sustain it. SPARC is funded by private industry, building on the foundations of decades of fruitful, government funded research while harnessing the resources, agility and risk tolerance of the start-up culture.
Tuesday, April 30th, 2019
- Noon Colloquium
- An introduction to radiatively driven stellar winds
- Time: 12:00 pm - 1:15 pm
- Place: 4421 Sterling Hall, Noon Talk
- Speaker: Wolf-Rainer Hamann, Institute for Physics and Astronomy, University of Potsdam
- Abstract: Stellar spectra that are dominated by bright and broad emission lines have been discovered by the French astronomers Wolf and Rayet 150 years ago, and must be attributed to strong outflow of matter. But only with the advent of ultraviolet spectroscopy in the 1970s it became known that stellar winds are ubiquitous among hot and luminous stars.
In principle, such winds can be driven by radiation pressure. The quantitative analysis of stellar-wind spectra requires adequate modeling of expanding stellar atmospheres. The evolution of massive stars and their final fate depends on their mass loss. This refers especially to the mass that might finally collapse into a Black Hole - i.e. such objects which are observed by gravitational waves when merging. - Host: Professor Emeritus Jay Gallagher
- Chaos & Complex Systems Seminar
- Year-end celebration
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Various, UW Madison
- Abstract: Following the tradition of recent years in which we had a delightful discussion of where we have come and where we might go with the seminars, this last seminar of the semester will be devoted to a continuation of that discussion without any formal speaker. We will also discuss what we want to do during our informal weekly lunches on the Memorial Union Terrace which begin on May 7th. This celebration will include expanded refreshments, to which your own culinary contribution is welcome.
- Host: Clint Sprott
- Council Meeting
- Time: 3:30 pm
- Place: 2314 Chamberlin Hall
Wednesday, May 1st, 2019
- Department Meeting
- Time: 12:15 pm
- Place: B343 Sterling Hall
Thursday, May 2nd, 2019
- Cosmology Journal Club
- Time: 12:00 pm - 1:00 pm
- Place: 5242 Chamberlin Hall
- Abstract: Please visit the following link for more details:
http://cmb.physics.wisc.edu/journal/index.html
Feel free to bring your lunch!
If you have questions or comments about this journal club, would like to propose a topic or volunteer to introduce a paper, please email Ross Cawthon (cawthon@wisc.edu) and Santanu Das (sdas33@wisc.edu). - Astronomy Colloquium
- Implications of gravitational wave detections for stellar astrophysics
- Time: 3:30 pm - 5:15 pm
- Place: 4421 Sterling Hall, Coffee and cookies 3:30 PM, Talk begins 3:45 PM
- Speaker: Lidia Oskinova, University of Potsdam
- Abstract: Stars with masses much higher than our Sun end their short lives in a gravitational collapse, leaving neutron stars and black holes behind. The detections of gravitational waves (GW) brought massive star astrophysics into the new era. A comprehensive understanding of massive star lives and deaths is urgently required to fully unleash the power of multi-messenger astronomy. In this talk I will briefly review what we presently know about massive stars, and highlight the key problems in our current understanding of neutron star and black hole progenitors. I will present our recent results from the study of massive stars in the SMC galaxy, which suggest that evolutionary paths of very massive stars at low and high metallicities are significantly different . Finally, I will discuss what the recent GW observations already have told us about massive stars, and how the different scenarios for the GW progenitors could be tested by massive star astrophysics.
- Host: Professor Emeritus Jay Gallagher
- R. G. Herb Condensed Matter Seminar
- Please note special time!
- Optical and transport properties of metals with nontrivial band geometry
- Time: 4:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Dima Pesin , University of Virginia
- Abstract: I will describe how the geometry of the band structure of metals manifests itself in their optical and transport properties. I particular, I will show that the natural optical activity of metals, equivalent to the so-called dynamic chiral magnetic effect, stems from the intrinsic magnetic moments of quasiparticles, and demonstrate that these magnetic moments can be of both intrinsic and extrinsic origin. I will also discuss optical Hall response of chiral crystals in the presence of a DC transport current – the gyrotropic Hall effect – and show that it is related to the Berry curvature dipole. The latter fact makes the gyrotropic Hall effect a diagnostic tool for topological properties of three-dimensional chiral metals.
- Host: Alex Levchenko
Friday, May 3rd, 2019
- Physics Department Colloquium
- Quantum mechanics of fluids in solids
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall
- Speaker: Dima Pesin , University of Virginia
- Abstract: In this talk, I will discuss how the quantum mechanics of Bloch electrons – the geometry of their wave functions - manifests itself in the observable properties of materials. Drawing intuition from the classic example of the anomalous Hall effect, I will discuss transport and optical phenomena in gapless topological systems, represented by the Weyl semimetal, as well as other metals with nontrivial band geometry. Primary focus of the discussion will be on the physical manifestations of the chiral anomaly and chiral magnetic effect in nonlocal transport, and optical activity of metals. I will also briefly touch upon the nonlinear transport and hydrodynamic properties of topological metals.
- Host: Alex Levchenko
- Physics Awards Banquet
- Time: 5:30 pm
- Place: Memorial Union - Tripp Commons
- Abstract: Awards presentation for student and alumni award winners.