Physics Colloquium


 Colloquia are held on Friday afternoon at 3:15 pm,
in Bennett Hall, Room 140, unless otherwise noted

Refreshments are provided before the Colloquium talk

Fall 2019

Speakers are currently being scheduled for the semester. Keep checking back for updates!!

  • September 6:  No colloquium; Department Picnic
  • September 13: Kevin Plaxco, U. California Santa Barbara, “Counting Molecules, Dodging Blood Cells: continuous, real-time molecular measurements directly in the living body”
    • The availability of technologies capable of tracking the levels of drugs, metabolites, and
      biomarkers in real time in the living body would revolutionize our understanding of health and
      our ability to detect and treat disease. Imagine, for example, a dosing regime that, rather than
      relying on your watch (“take two pills twice a day”), is instead guided by second-to-second
      measurements of plasma drug levels wirelessly communicated to your smartphone. Such a
      technology would likewise provide researchers and clinicians an unprecedented window into
      neurology and physiology, and could even support ultra-high-precision personalized medicine in
      which drug dosing is optimized minute-by-minute using closed-loop feedback control. Towards
      this goal, we have developed a biomimetic, electrochemical sensing platform that supports the
      high frequency, real-time measurement of specific molecules (irrespective of their chemical
      reactivity) in situ in the bodies of awake, freely moving subjects.
  • September 20, 3:00 start:  Alexander Turbiner, ICN-UNAM & Stony Brook U., “Choreography in Physics, in (non)-Newtonian gravity (living in motion)”
  • October 4:  Christopher Spalding, Yale: “Primordial Sculpting of Planetary System Architectures”
    • The census of extrasolar planets detected continues to grow well into the
      thousands. With this number, we transition from the age of discovery, and move toward
      the age of characterization. Specifically, a growing set of exoplanetary systems have
      emerged as exhibiting large orbital misalignments with respect to both other planets in
      the system, and with respect to the host star’s spin axis. In contrast, our Solar system
      exhibits small inclinations and the Sun’s spin axis is well-aligned. In this talk, I explore
      the hypothesis that the ultimate 3-dimensional architectures of planetary systems is
      largely set by physical mechanisms playing out during the opening 10-100 million years
      of planetary system evolution. I will show how the stellar quadrupole moment of young
      stars may destabilize planetary systems, and how nearby stars may tilt entire systems
      by over 90 degrees. I discuss tests of these hypotheses promising to emerge within
      upcoming datasets, and important lessons that looking upwards have revealed about
      our own planet’s history.
  • October 11: Scott Randall, Harvard-Smithsonian Center for Astrophysics, “X-Ray Studies of Clusters of Galaxies”
    • Twenty years after its launch, Chandra remains the highest angular
      resolution X-ray observatory ever constructed. This resolution, combined with a
      relatively large effective area and a predictable instrumental background, have allowed
      significant advancements covering a wide range of astrophysical topics, including the
      co-evolution of supermassive black holes and their host galaxies, black hole accretion,
      supernovae and their progenitors, the interiors of neutron stars, the evolution of
      massive stars, the interaction of exoplanets and their stars, the physics of galaxy
      clusters, the nature of dark matter and dark energy, and the evolution of the universe
      itself. I will pay particular attention to what Chandra has helped us learn about AGN
      feedback, galaxy clusters, and the nature of dark matter. I will also briefly discuss the
      outlook for X-ray astronomy over the coming decade and beyond.
  • October 25: Feng Yan, University of Alabama:  “Photovoltaics for Renewable Energy: Cubic and Non-Cubic Chalcogenides Thin Film Solar Cell”
    • Photovoltaic (PV) materials and devices, commonly known as solar cells, directly convert sunlight into electrical energy, is one of the most efficient renewable energy systems. Chalcogenides thin films solar cells dominate the thin-film solar cells markets. Cubic CdTe thin-films are today’s dominant thin-film technology in the photovoltaic industry.  The efficiency of thin-film CdTe solar cells has increased from 17% five years ago to 22% now, surpassing the market-dominant multi-crystalline Si technology.  Several technology components have contributed to the sudden rise in efficiency. This seminar overviews the recent learning on new functional layers added to CdTe films to boost the device performance. Also, a new type of non-cubic chalcogenides materials with quasi-one-dimensional ribbons provide unique carrier transport pathway to suspend the drawback in cubic chalcogenides thin-film solar cells can achieve 7% in our lab. With the learning from cubic CdTe and the theoretical calculation, a new type of thin films solar cells could be integrated into the high throughput manufacturing.
  • November 15:  Emanuele Berti, Johns Hopkins U., “Gravitational waves from compact binaries: implications for fundamental physics and astrophysics”
    • The observation of compact binary mergers by the LIGO/Virgo collaboration marked the
      dawn of a new era in astronomy. The space-based detector LISA will fulfill this vision by
      opening a new observational window at low frequencies. The gravitational radiation
      emitted by compact binaries encodes important information on their astrophysical
      formation mechanism. Furthermore, compact objects – whether in isolation or in binaries
      – are excellent astrophysical laboratories to probe our understanding of high-energy
      physics and strong-field gravity. I will discuss how gravitational wave detectors can
      further our understanding of the formation and evolution of compact binaries, test
      gravity in the strong field regime, and look for smoking guns of new physics.
  • December 6: Karissa Tilbury, U. Maine