Events During the Week of October 5th through October 12th, 2025
Monday, October 6th, 2025
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Title to be announced
- Time: 12:00 pm - 1:00 pm
- Place: 2241 Chamberlin Hall
- Speaker: Dick Majeski, PPPL
- Host: Cary Forest
Tuesday, October 7th, 2025
- Graduate Program Event
- Spring 2026 GAANN Fellowship Q&A Session
- Time: 3:00 pm - 4:00 pm
- Place: 2314 Chamberlin or
- Speaker: Tulika Bose
- Abstract: We invite anyone who is interested in learning more about the GAANN fellowship to this Q&A sessions
The UW–Madison Department of Physics is a recipient of funding for Graduate Assistance in Areas of National Need (GAANN) fellowships. This fellowship is intended to support current or prospective Physics PhD students with excellent academic records and who have demonstrated a financial need and who plan to pursue research, teaching, and learning in the field of physics – and we want you to consider applying for this fellowship! Wednesday, October 8th, 2025
- Astronomy Colloquium
- Exoplanet Seminar
- The Geology of Planetary Atmospheres
- Time: 10:00 am - 11:00 am
- Place: 6515 Sterling Hall
- Speaker: Prof. Ray Pierrehumbert , Halley Professor of Physics, University of Oxford
- Abstract: In this lecture, I will highlight some examples of the interplay between planetary envelopes and planetary interiors, focusing on lava planets, "hot rocks" (rocky planets too hot to support surface liquid water but not hot enough to have molten surfaces), the deep carbon cycle on habitable rocky worlds, and sub-Neptunes. Recent JWST data driving these inquiries will be surveyed. The general programme is to determine the extent to which astronomical observations -- which probe only the outer skin of a planet's volatile envelope (if present)-- together with mass, radius and age data can constrain the composition and structure of the interior, which cannot be directly observed. sub-Neptunes present an especially interesting case, because many currently accessible targets have a predominantly rocky composition (by mass), surrounded by a lower molecular weight envelope which interacts physically and chemically with a permanent magma ocean at the silicate/envelope interface. For sub-Neptunes with a sufficiently massive envelope, the interface with the silicate mantle can be hot enough to drive the silicate itself supercritical, blurring the distinction between mantle and envelope. Lack of experimental data on equations of state, geochemical reaction constants and opacities currently constitutes a serious impediment to progress in modelling sub-Neptune thermochemical structure and evolution.
- Host: Thomas Beatty
- Physics Education Innovation Seminar
- The Development of Physics 106: The Physics of Sport from 4 students to 300
- Time: 12:00 pm - 1:00 pm
- Place: B343 Sterling Hall
- Speaker: Jim Reardon, UW-Madison
- Abstract: Physics 106 was first offered in Fall 2022 (as Physics 206) with an enrollment of 4 students, and has grown to have an enrollment (in Fall 2025) of 300 students. How did this happen? A brief description will be given of the evolution of Physics 106 instruments and methods, and an attempt will be made to assess the feedback loops responsible for the growth in enrollment.
- Host: PEIF Committee
- WiCOR Lecture
- WiCOR Lecture: Understanding the Chemical Origins of Life
- Time: 7:30 pm
- Place: DeLuca Forum, Discovery Building
- Speaker: Professor Jim Cleaves, Department of Chemistry, Howard University
- Abstract: Professor Jim Cleaves (Department of Chemistry, Howard University) will present a lecture entitled “Understanding the Chemical Origins of Life” for the Fall 2025 WiCOR Lecture on Oct 8 at 7:30 PM. This event is open to the public – please share with friends and family! Learn more at:
- Host: Wisconsin Center for Origins Research
Thursday, October 9th, 2025
- WiCOR Seminar
- Wisconsin Center for Origins Research Seminar: Prebiotic Chemical Diversity
- Time: 12:05 pm
- Place: Chemistry Building 1315
- Speaker: Professor Jim Cleaves, Department of Chemistry, Howard University
- Abstract: Professor Jim Cleaves (Department of Chemistry, Howard University) will present a seminar entitled “Prebiotic Chemical Diversity” for the Fall 2025 Wisconsin Center for Origins Research Seminar on Oct 9 at 12:05 PM. This event is intended for a research audience. Learn more at:
- Host: Wisconsin Center for Origins Research
- Astronomy Colloquium
- Old New Worlds: Planetary Destruction and Renewal over Stellar Lifetimes
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Dr. Chris O'Connor, Northwestern University
- Abstract: Planetary systems are ubiquitous, but not eternal. In this two-part talk, I will describe recent work on long-term stellar evolutionary and dynamical processes that shape, transform, and destroy planets and planetary systems. In part one, I will introduce the extraordinary exoplanet WD1856b and summarize recent theoretical and observational progress, and enduring challenges, in understanding its formation and evolution. In part two, I will discuss the timely "breaking the chains" problem in exoplanet dynamics, which seeks an explanation for the declining prevalence of mean-motion resonances (MMRs) with age in compact planetary systems. I will describe a possible scenario for breaking the chains through planetesimal interactions and its implications about exoplanet architectures beyond the "ice line."
- Host: Nicholas Stone
Friday, October 10th, 2025
- Theory Seminar (High Energy/Cosmology)
- Quantum Gravity Fluctuations in Causal Diamonds and Cosmology
- Time: 11:00 am - 12:30 pm
- Place: Chamberlin 5280
- Speaker: Lars Aalsma, Minnesota U., Duluth
- Abstract: Given that the Planck length is 10^{-35} meters, directly measuring quantum gravity effects does not seem feasible. For this reason, finding physical systems where quantum fluctuations are enhanced is crucial to put theoretical ideas about quantum gravity to the test. Work by Verlinde and Zurek in 2019 has suggested that an enhancement of geometrical fluctuations takes place in a ‘causal diamond’: the causally accessible region to an observer in a finite time interval. This has been dubbed the ‘VZ-effect’. If correct, this leads to a quantum gravitational background noise that can be measured by future dedicated interferometry experiments. In this talk, I will explain the status of this proposal and highlight some of its controversial aspects. To address these controversies, I will show that the fluctuations proposed by VZ have a natural interpretation in inflationary cosmology. This clarifies the assumptions that need to be satisfied for the ‘VZ-effect' to be observable.
- Host: Gary Shiu
- Physics Department Colloquium
- Superfluid ³He: Science and Serendipity
- Time: 3:30 pm - 4:30 pm
- Place: Chamberlin 2241
- Speaker: Bill Halperin, Northwestern University
- Abstract: The remarkable discovery of superfluid ³He has paved the way for the modern era of quantum condensed states of matter. I recount this development from a personal perspective highlighting the role of serendipity and the interplay between experiment and prediction. There are fits and starts, beautiful physics, a road that continues with rich promise and the occasional disappointment. Yet superfluid ³He is inspirational for unconventional superconductivity, possible condensates of dense quark matter, cores of neutron stars, and proposed sensors of dark matter.
- Host: Alex Levchenko