Events at Physics |
Events During the Week of February 16th through February 23rd, 2020
Sunday, February 16th, 2020
- Wonders of Physics
- Wonders of Physics Show
- Time: 1:00 pm - 2:15 pm
- Place: 2103 Chamberlin
- Abstract: Scheduled presentations of The Wonders of Physics and a Physics Fair are given on the UW-Madison campus for the general public in mid-February each year. Free tickets are recommended and are available after January 1st using the On-Line Ticket Form (http://sprott.physics.wisc.edu/cgi-bin/tickleft.exe). Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu.
- Host: Clint Sprott / Wonders of Physics
- Wonders of Physics
- Wonders of Physics Show
- Time: 4:00 pm - 5:15 pm
- Place: 2103 Chamberlin
- Abstract: Scheduled presentations of The Wonders of Physics and a Physics Fair are given on the UW-Madison campus for the general public in mid-February each year. Free tickets are recommended and are available after January 1st using the On-Line Ticket Form (http://sprott.physics.wisc.edu/cgi-bin/tickleft.exe). Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu.
- Host: Clint Sprott / Wonders of Physics
Monday, February 17th, 2020
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Understanding, Predicting, and Manipulating Reduced Transport Regimes in Fusion Plasmas
- Time: 12:05 pm - 12:55 pm
- Place: 2241 Chamberlin Hall
- Speaker: David Hatch, Institute for Fusion Studies, University of Texas at Austin
- Abstract: Following a half century of extraordinary progress in plasma magnetic confinement via tokamaks, with, for example, the fusion triple product increasing at a rate surpassing Moore’s law, magnetic confinement finds itself poised on the brink of high fusion gain. The narrow transport barrier that forms at the edge of an H-mode fusion plasma will, perhaps, be the largest determining factor in making the final step to a burning plasma. This transport barrier arises when the conventional plasma turbulence mechanisms are suppressed. This allows a ‘pedestal’—a region of steep pressure gradients—to form, drastically boosting the plasma confinement. ITER, and nearly all other prospective burning plasma devices, are designed to exploit edge transport barriers to achieve their goals.
This talk presents recent breakthroughs in understanding and predicting the ‘residual’ turbulence in transport barriers, which has been difficult to model due to the extreme conditions characteristic of a transport barrier. I will survey the classes of fluctuations that remain in transport barriers; describe how high performance computing is enabling unprecedented physics understanding; discuss how pedestal transport may extrapolate to unfamiliar parameter regimes (e.g., ITER); and describe connections between transport barriers in tokamaks and stellarators. The developing capacity to understand, predict, and manipulate turbulent transport has the potential to enable the realization of optimized configurations that will enable fusion gain on faster time scales and at greatly reduced cost. - Host: Jan Egedal
- Atomic Physics Seminar
- QC Cluster Seminar
- tbd
- Time: 3:00 pm - 4:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Professor Gleb Finkelstein, Duke University
- Abstract: tbd
- Host: Mark Saffman
Tuesday, February 18th, 2020
- Chaos & Complex Systems Seminar
- Drivers of megadiversity in the orchids, the largest family of flowering plants
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Tom Givnish, UW Department of Botany
- Abstract: Orchids are the most diverse family of angiosperms, with more species than mammals, birds, and reptiles combined. Many ideas have been advanced to account for their extraordinary diversity, but they have – until quite recently – been impossible to test because we lacked a good phylogeny (family tree) for the orchids. My colleagues and I have now developed a well-resolved phylogeny for the orchids, based on large numbers of chloroplast genes, and I will show how we can use this phylogeny to identify the age and place of origin of the orchids, assess the role of different orchid traits in driving high rates of speciation, and reconstruct the geographic spread of orchids across the planet. I will also describe some of the remarkable aspects of the ecology of this endlessly fascinating group that have recently come to light, mention some of the notable aspects of orchid diversity in Wisconsin, and sketch some interesting scientific and conservation issues that should be explored in the future.
- Host: Clint Sprott
- "Physics Today" Undergrad Colloquium (Physics 301)
- Dark Matter Detection in the Era of LZ
- Time: 1:20 pm - 2:10 pm
- Place: 2241 Chamberlin Hall
- Speaker: Kimberly J. Palladino, UW Madison Department of Physics
- Host: Sridhara Dasu
- Theory Seminar (High Energy/Cosmology)
- Connecting the dots: from astronomical surveys and experiments to fundamental physics of dark universe
- Time: 4:00 pm
- Place: 5280 Chamberlin
- Speaker: Yao-Yuan Mao, Rutgers
- Abstract: The standard model of cosmology, despite its success in explaining most current observations, consists of several mysterious components, such as dark matter, dark energy, and inflation. Current and upcoming multiwavelength sky mappers, gravitational wave observations, and particle experiments will provide an unprecedented collection of complementary datasets, which have brought, and will continue to bring us novel and exciting discoveries. One of the main challenges in the next decade is to translate these discoveries into solid understandings of the fundamental physics of the universe, especially its dark components. We hence need to carefully connect the “dots” between theories and observations. In this talk, I will demonstrate the pivotal roles of numerical simulations, empirical models, and statistical analyses in the said connection. I will illustrate how theoretical uncertainties impact the interpretation of observations and how we mitigate those impacts, with specific case studies including direct detection experiments, gravitational lensing, and dwarf galaxy surveys (as dark matter probes). Finally, taking the LSST Dark Energy Science Collaboration as an example, I will discuss how we work together as a community to be prepared to answer fundamental questions about the dark universe with upcoming datasets.
- Host: Dan Chung
Wednesday, February 19th, 2020
- No events scheduled
Thursday, February 20th, 2020
- R. G. Herb Condensed Matter Seminar
- Entanglement and metrology in an array of alkaline-earth atoms
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Jacob P. Covey, Caltech
- Abstract: Quantum entanglement is the central resource in quantum information science applications including metrology, computation, and communication. A defect-free array of isolated, neutral particles with long-range, state-dependent interactions is an attractive architecture for scalable entanglement generation. In this talk, I will describe two platforms that offer long-range interactions: polar molecules, and atoms in highly-excited Rydberg states. I will focus on alkaline-earth atoms (AEAs), which also possess ultra-narrow ‘clock’ transitions for precision metrology. I will describe the techniques we pioneered for cooling and imaging single AEAs in optical tweezer arrays for the first time [1,2], as well as a new platform for metrology based on single-atom readout in an atomic array clock [3]. Further, I will discuss recent observations of high-fidelity control, detection, and entanglement using Rydberg states [4]. I will close with an outlook of future research directions.
[1] A. Cooper, JPC, et al., “Alkaline-Earth Atoms in Optical Tweezers”, Phys. Rev. X 8, 041055 (2018).
[2] JPC, et al., “2000-Times Repeated Imaging of Strontium Atoms in Clock-Magic Tweezer Arrays”, Phys. Rev. Lett. 122, 173201 (2019).
[3] I. S. Madjarov, …, JPC, et al., “An Atomic-Array Optical Clock with Single-Atom Readout”, Phys. Rev. X 9, 041052 (2019).
[4] I. S. Madjarov*, JPC*, et al., “High-Fidelity Control, Detection, and Entanglement of Alkaline-Earth Rydberg Atoms”, arXiv:2001.04455 (2020). - Host: Saffman
- 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).
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- The TeV-PeV Diffuse Neutrino Background
- Time: 2:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Nathan Whitehorn, UCLA
- Abstract: In 2014, the IceCube Neutrino Observatory announced the discovery of an isotropic, isoflavor diffuse background of neutrinos with energies extending from 10 TeV to well above 1 PeV, presumably associated with the unknown emitters of high-energy cosmic rays. Six years later, the origin of these neutrinos remains a mystery. The background is, within measurement uncertainties, uncorrelated with any of the standard catalog of high-energy sources (our galaxy, blazars, gamma-ray bursts, etc.), challenging explanations involving simple models. The 2017 detection of neutrino emission from the distant blazar TXS 0506+056 has only deepened this mystery. In this talk, I will discuss the current state of our knowledge of the high-energy neutrino sky and outline the next steps in the experimental program to resolve these questions.
- Host: Albrecht Karle
- Theory Seminar (High Energy/Cosmology)
- Future cosmology with CMB lensing and galaxy clustering
- Time: 4:00 pm
- Place: 5280 Chamberlin
- Speaker: Marcel Schmittfull, Institute for Advanced Study
- Abstract: Next-generation Cosmic Microwave Background experiments such as the Simons Observatory, CMB-S4 and PICO aim to measure gravitational lensing of the Cosmic Microwave Background an order of magnitude better than current experiments. The lensing signal will be highly correlated with measurements of galaxy clustering from next-generation galaxy surveys such as LSST. This will help us understand whether cosmic inflation was driven by a single field or by multiple fields. It will also allow us to accurately measure the growth of structure as a function of time, which is a powerful probe of dark energy and the sum of neutrino masses. I will discuss the prospects for this, as well as recent progress on the theoretical modeling of galaxy clustering, which is key to realize the full potential of these anticipated datasets.
- Host: Dan Chung
Friday, February 21st, 2020
- PGSC Professional Development Seminar
- How to Get the Most out of Academic Articles
- Time: 2:30 pm - 3:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Alex Pizzuto, Physics Graduate Student
- Abstract: Getting all the information out of a dense academic article is a challenge no matter what point you’re at in your physics career. Even if you’re reading a paper very close to your field, language, figures, and presentation style can act as barriers to understanding the take-home message of the work. I’ll cover strategies for approaching articles geared towards overcoming these barriers. You’ll improve your research efficiency by being able to interpret the motivations, methods, results, and implications of an article after a 5-minute read.
- Host: Rob Morgan, graduate student
- Physics Department Colloquium
- It's all About Matter
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall
- Speaker: Young-Kee Kim , U Chicago
- Abstract: Subatomic-particle research has made enormous progress in the 20th Century by looking inside matter at deeper and deeper levels. It is as if we were peeling the layers of an onion in the hopes of finding more basic rules for the structure of nature. Although the concept of the ultimate building blocks of matter has been modified in several essential respects in the last century, Democritus’s idea remains at the foundation of modern science. Great experiments of the 20th century have led to the discovery of ever-smaller entities that make up what were once thought to be indivisible particles. Moreover, the theory of the very small has been shown to be intimately connected to the largest scales imaginable – cosmology and the beginnings of the Universe. Despite these considerable successes, the current theory has within it the seeds of its own demise and is predicted to break down when probed at even smaller scales. One of such examples is the origin of mass of fundamental particles. We have achieved a beautiful and profound understanding of how fundamental particles acquire their mass, but the mass values remain deeply mysterious. In addition, we learned that ordinary matter supplies only a small fraction of mass in the Universe. We continue to peel away at the more hidden layers of truth with the hope of discovering a more elegant and complete theory. But as is the case with the onion, we must wonder whether there will ever emerge an ultimate layer where the peeling must stop.
- Host: Tulika Bose