Physics and Astronomy - Colloquium Schedule

Colloquia are presented on Thursdays at 3:45 pm in Room 245 of the Physics Building, unless otherwise noted.

Refreshments are served at 3:30 pm.


2017-2018 Schedule


Thursday, September 7, 2017

     Speaker: Victor Yakovenko, University of Maryland

      Title: Economic inequality from a statistical physics point of view

      Abstract: By analogy with the probability distribution of energy in statistical physics, the probability distribution of money among the agents in a closed economic system is expected to follow the exponential Boltzmann-Gibbs law, as a consequence of entropy maximization.  Analysis of empirical data shows that income distributions in the USA, European Union, and other countries exhibit a well-defined two-class structure.  The majority of the population (about 97%) belongs to the lower class characterized by the exponential ("thermal") distribution.  The upper class (about 3% of the population) is characterized by the Pareto power-law ("superthermal") distribution, and its share of the total income expands and contracts dramatically during booms and busts in financial markets.  Such a two-class distribution can be obtained analytically for a combination of additive and multiplicative stochastic processes.  Globally, data analysis of energy consumption (and CO2 emission) per capita around the world in the last 30 years shows decreasing inequality and convergence toward the exponential probability distribution, in agreement with the maximal entropy principle.  All papers are available at http://physics.umd.edu/~yakovenk/econophysics/.


Thursday, September 14, 2017 (Note special location)

     Speaker: Kip Thorne

     Location:  Spencer M. Partrich Auditorium, Wayne State University Law School

      Title: Geometrodynamics: Exploring the nonlinear dynamics of curved spacetime via computer simulations and gravitational wave observations

      Abstract:  A half century ago, John Wheeler challenged his students and colleagues to explore Geometrodynamics:  the nonlinear dynamics of curved spacetime. How does the curvature of spacetime behave when roiled in a storm, like a storm at sea with crashing waves. Dr. Thorne and collaborators tried to explore this, and the failed. Success eluded us until two new tools became available: computer simulations, and gravitational wave observations. Dr. Thorne will describe what these have begun to teach us, and he will offer a vision for the future of Geometrodynamics.

About the speaker: Kip Thorne is the Richard P. Feynman Professor of Theoretical Physics, Emeritus, at the California Institute of Technology in Pasadena, California. He is a theoretical physicist specializing in the astrophysical effects of Einstein's General Theory of Relativity, especially black holes and gravitational waves. He was one of the founding members of the Laser Interferometer Gravitational Wave Observatory (LIGO) in 1984. The goal of LIGO is to observe gravitational waves from extreme astrophysical events. Gravitational waves were first predicted by Albert Einstein one-hundred years ago this year. While there is good indirect evidence for gravitational waves based on the behavior of binary pulsars, the first direct measurement of a gravitational wave was announced by the LIGO team on February 11, 2016. Two independent laser interferometers in Livingston, Louisiana and Hanford, Washington observed a gravitational wave on September 14, 2015. Analysis of the signal indicates the wave was produced by the collision of two black holes more than one-billion light years away. Professor Thorne is an accomplished author of books for scientists and the general public, and he was the scientific consultant and Executive Producer of the film Interstellar.

A video of this colloquium may be found HERE (YouTube)


Thursday, September 21, 2017

     Speaker: Boris Yakobson, Rice University

      Title: Predictive modeling of low-dimensional materials, nanotubes, graphene, and beyond

      Abstract: 

Comprehensive tools of materials modeling are derived from the principles of physics and chemistry, empowered by high performance computing. Together, this allows one to make verifiable predictions of novel physical structures with specific, often useful or even extraordinary, properties. Nanotubes offer one such lesson [1], where atomic makeup and defects dynamics lead to the understanding of their strength and failure physics on one hand, while also reveal the origins of chiral symmetry in nano-carbon synthesis [2]. A second, very recent, example is the prediction of pure mono-elemental 2D boron, its particular structures to form on Ag(111), which culminated in recent experimental confirmations. We may also mention, if time permits, its physical properties like new 2D-superconductor [3], now-detected Dirac cone dispersion, still-sought 2D-plasmonics, and catalysis.

[1] M. Davenport, Chemical & Engineering News, 93, 10 (2015) || B.I. Yakobson and R.E. Smalley, American Scientist, 85, 324-337 (1997).

[2] F. Ding et al. Proc. Natl. Acad. Sci., 106, 2506 (2009) || V. Artyukhov et al. Proc. Natl. Acad. Sci. 109, 15136 (2012) || V. Artyukhov et al. Phys. Rev. Lett. 114, 115502 (2015) || V. Artyukhov - E. Penev, et al. Nature Comm. 5, 489 (2014).

[3] Z. Zhang et al. Nature Chem. 8, 525 (2016) || Z. Zhang et al. Angewandte Chemie Int. Ed. 54, 13022 (2015) || E. Penev - A. Kutana et al. Nano Lett. 16, 2522 (2016) || Z. Zhang et al. Nano Lett. 6, 6622 (2016) || A. Brotchie, Nature Reviews, doi:10.1038/natrevmats.2016.83 (2016) || S. Shirodkar, Y. Huang et al. (unpublished) || Y. Liu et al. Nature Energy 2, 17127 (2017).


Thursday, September 28, 2017

     Speaker: Michael Murray, University of Kansas

      Title: There and Back Again: A Journey from classical physics to quantum mechanics and back to classical fields.

      Abstract: When the nucleus was discovered it appeared to be a massive classical charged sphere at the heart of atom. Later protons and neutrons were discovered inside the nucleus. Later still it was found that  protons and neutrons are themselves made up of quarks held together by gluons. Such objects are described by quantum field theories. As the energy of our colliders has increased we have found more and more gluons inside the nucleus. At some point we expect the gluons to fuse together into a glass like state called the Color Glass Condensate. This new state of quantum matter may actually behave like a classical field.


Thursday, October 5, 2017

     Speaker: Chris Adami, Michigan State University

      Title: What quantum optics can tell us about black holes

      Abstract: Black holes are astrophysical objects whose reality is beyond doubt. However, many aspects of them remain mysterious because observations are difficult and experiments are impossible. Research in the last two decades has revealed a remarkable analogy between the mathematics of quantum black holes and certain quantum optical systems, which makes it possible to study "black hole analogues" in the lab, and to better understand some of the seemingly paradoxical features of black holes. I review recent breakthroughs in black hole physics that were inspired by the quantum optics analogy, and that have removed some of the paradoxes surrounding black holes. 

      About the speaker: Dr. Adami is Professor for Microbiology and Molecular Genetics & Physics and Astronomy at Michigan State University in East Lansing, Michigan. As a computational biologist, Dr. Adami's main focus is Darwinian evolution, which he studies theoretically, experimentally, and computationally, at different levels of organization (from simple molecules to brains). He has pioneered the application of methods from information theory to the study of evolution, and designed the "Avida"" system that launched the use of digital life (mutating and adapting computer viruses living in a controlled computer environment) as a tool for investigating basic questions in evolutionary biology. He was also a Principal Scientist at the Jet Propulsion Laboratory where he conducted research into the foundations of quantum mechanics and quantum information theory. Dr. Adami earned a BS in physics and mathematics and a Diplom in theoretical physics from the University of Bonn (Germany) and MA and PhD degrees in theoretical nuclear physics from the State University of New York at Stony Brook. He wrote the textbook "Introduction to Artificial Life" (Springer, 1998) and is the recipient of NASA's Exceptional Achievement Medal. He was elected a Fellow of the American Association for the Advancement of Science (AAAS) in 2011.


Thursday, October 12, 2017

     Speaker: Pushpa Bhat (FNAL)

      Title: Fifty Years of Particle Physics and Discoveries at Fermilab

      Abstract: Fermilab, the premier laboratory for elementary particle physics and accelerator research in the U.S., has been at the forefront of fundamental discoveries for the past fifty years.  It has had the distinction of discovering three fundamental particles – the bottom and top quarks, and the tau neutrino, as well as leading the detailed exploration of the Standard Model, and making major advances in the pursuit of the Higgs boson.  The home of the highest energy proton accelerator and particle collider in the world until the end of the last decade, Fermilab has also led the development of enabling technologies for powerful accelerator facilities.  In this talk, I will present the highlights of the past fifty years of particle physics at Fermilab and discuss its future program and role in the new global enterprise of particle physics.

     About the speaker: Pushpa Bhat is a senior scientist at Fermi National Accelerator Laboratory (Fermilab), Deputy Head of Fermilab Program Planning, and an Adjunct Professor and graduate faculty at Northern Illinois University. After receiving her Ph.D. in physics from Bangalore University, India, in 1982 and a brief stint as a scientific officer at the Eindhoven University Cyclotron Lab in the Netherlands, she moved to the U.S. and carried out postdoctoral work in experimental high energy physics at Duke University and Fermilab.  Her research career has spanned applied physics, nuclear physics and experimental particle physics, from keV energies to the energy frontier. Bhat is a Fellow of the American Physical Society (APS) and the American Association for the Advancement of Science (AAAS).  She has served as the Chair of the APS Forum on Physics and Society (FPS) and as Chair of several committees.  She currently serves on the APS Council and on the APS Board of Directors, and as Secretary for the International Committee on Future Accelerators (ICFA).


Thursday, October 19, 2017

     Speaker: Zhi-Feng Huang, Wayne State University

      Title: Exploring microstructures and dynamics of complex systems: Ordering, chirality, defects, and scale coupling

      Abstract: One of the long-lasting challenges in the study of advanced materials is how to effectively tackle vast complexity of the system that is of nonequilibrium nature and involves multiple spatial and temporal scales. Of particular importance is the bridging between material microstructural details and mesoscopic characteristics such as surface patterns or interfacial structures, for which much of recent theoretical effort has been put on the development of novel density-field based approaches across different scales. In this talk I will discuss some recent advances in this field for modeling material microstructures and dynamics and some of the ongoing challenges. Sample topics include the emergence of ordering phases, the control of 2D structure or pattern chirality and chiral elastic properties, structures and collective dynamics of topological defects in binary 2D materials such as h-BN, and the interface lattice pinning effect during material growth due to the coupling between micro and meso spatial scales.


Thursday, October 26, 2017

     Speaker: Christopher Kelly, Wayne State University

      Title: Nanoscale membrane curvature revealed by polarized localization microscopy

      Abstract: Many essential biological processes depend on the interaction of lipids, proteins, and carbohydrates at length scales that are unresolvable by conventional optical microscopes. We have combined super-resolution microscopy methods to create polarized localization microscopy (PLM). With PLM, we have measured membrane curvature as small as 20 nm radii, measured curvature-induced molecular sorting, and a local change in the local membrane viscosity. Further, we have discovered that cholera toxin subunit B self-assembles to form nanoscale membrane buds in quasi-one component bilayers to facilitate its immobilization and internalization into cells. We will discuss the physics of PLM and the mechanisms by which cholera toxin bends membranes.


Thursday, November 2, 2017

     No Colloquium (Fall Get-Together)


Thursday, November 9, 2017

     Speaker: Ken Ritchie, Purdue University

      Title: High-speed single molecule tracking of proteins in E. coli

      Abstract: All living cells are encapsulated by an outer envelope, which contains a fluid phospholipid-based membrane that structurally delineates the inside of the cell from its environment. Embedded within this membrane is the machinery (proteins) required for the cell to sense and interact with its environment. As such, one expects that there are mechanisms in place to control the location and mobility of the membrane proteins in the fluid membrane in order to perform complex and critical tasks. In this talk, I will present our group's recent single molecule mobility studies into the (dynamic) organization of the cellular membranes of E. coli bacteria performed at acquisition rates up to 1 kHz. Examples will include the structure of the polar region of the inner membrane as seen by the serine chemoreceptor Tsr and investigations into interactions of the iron transporter FepA in the E. coli outer membrane with the inner membrane protein TonB.

      About the speaker: Dr. Ritchie is a professor and the Associate Head of Department of Physics and Astronomy at Purdue University. He obtained his PhD at University of British Columbia in Vancouver in 1998, and was the Group Leader in the Kusumi Membrane Organizer Project in Nagoya, Japan in 1998-2005 and an assistant professor at Nagoya University in 2000-2005. He joined Purdue University in 2005 as a professor of physics and is the associate head of the department since 2015.


Thursday, November 16, 2017

     No Colloquium -- UG Research Day


Thursday, November 23, 2017

     No Colloquium -- Thanksgiving


Thursday, November 30, 2017

     Speaker: Jenny Thomas, University College London

      Title: TBD

      Abstract: 


Thursday, December 7, 2017

     Speaker: Oleg D. Lavrentovich, Kent State University

      Title: Using liquid crystals to command swimming bacteria

      Abstract: Self-propelled bacteria are marvels of nature. If we can control their dynamics, we could use it to power dynamic materials and microsystems of the future. Unfortunately, bacterial swimming is mostly random in isotropic liquids such as water and is difficult to control by factors other than transient gradients of nutrients. We propose to command the dynamics of bacteria by replacing water with water-based liquid crystals. The long-range orientational order of the liquid crystal can pre-patterned into various structures by a plasmonic photoalignment technique [1]. The experiments demonstrate that the liquid crystals command the dynamics of bacteria, namely, the trajectories of swimming, polarity of motion, and distribution of bacteria in space [2]. The study of bacteria-liquid crystal system might result in approaches to harness the energy of collective motion for micro-robotic, biomechanical, and sensing devices, as well as micro-mixing and transport of micro-cargo. The work is supported by NSF grants DMR-1507637 and DMS-1729509.

[1] C. Peng, Y. Guo, T. Turiv, M. Jiang, Q.-H. Wei, O.D. Lavrentovich, Patterning of Lyotropic Chromonic Liquid Crystals by Photoalignment with Photonic Metamasks, Advanced Materials 2017, 1606112 (2017).

[2] C. Peng, T. Turiv, Y. Guo, Q.-H. Wei, O.D. Lavrentovich, Command of active matter by topological defects and patterns, Science 354, 882 (2016).

      About the speaker: Oleg D. Lavrentovich received his Ph.D. (1984) and Doctor of Science (1990) degrees in Physics and Mathematics from the Ukrainian Academy of Sciences for his research on topological defects in liquid crystals. In 1992 he joined the Liquid Crystal Institute at Kent State University. He served as the director of Institute in 2003-2011. He is currently a Trustees research professor affiliated with the Department of Physics, Chemical Physics Interdisciplinary program and the Liquid Crystal Institute at Kent State. His current research focuses on electro-optics of liquid crystals, topological defects, hybrid colloid-liquid crystal systems, liquid crystals as active matter and liquid crystals as nonlinear electrolytes. He is the editor of Liquid Crystals Reviews (Taylor & Francis), associate editor of Soft Matter (Royal Society of Chemistry), Fellow of APS and SPIE.


WINTER BREAK


Thursday, January 18, 2018

     Speaker: TBD

      Title: TBD

      Abstract: 


Thursday, January 25, 2018

     Speaker: ChunNing (Jeanie) Lau, Ohio State University

      Title: TBD

      Abstract: 


Thursday, February 1, 2018

     Speaker: Reserved

      Title: TBD

      Abstract: 


Thursday, February 8, 2018

     Speaker: Reserved

      Title: TBD

      Abstract: 


Thursday, February 15, 2018

     Speaker: Reserved

      Title: TBD

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Thursday, February 22, 2018

     Speaker: Reserved

      Title: TBD

      Abstract: 


Thursday, March 1, 2018

     Speaker: David Ceperley, University of Illinois at Urbana-Champaign (TBD)

      Title: TBD

      Abstract: 


Thursday, March 8, 2018

     Speaker: TBD

      Title: TBD

      Abstract: 


Thursday, March 15, 2018

     No Colloquium - Spring break


Thursday, March 22, 2018

     Speaker: Declan Keane, Kent State University

      Title: TBD

      Abstract: 


Thursday, March 29, 2018

     Speaker: Berry Jonker, Naval Research Laboratory

      Title: TBD

      Abstract: 


Thursday, April 5, 2018

     Speaker: Aaron Pierce, University of Michigan

      Title: TBD

      Abstract: 


Thursday, April 12, 2018

     No Colloquium -- Graduate Research Day


Thursday, April 19, 2018 (Vaden Miles Lecture)

     Speaker: J. Michael Kosterlitz, Brown University (2016 Nobel Prize in Physics)

      Title: TBD

      Abstract: 


WSU colloquia from years past may be found here.