Past Events

  • Department Colloquium

    David Rittenhouse Laboratory, A8

    Speakers: Robyn Sanderson, Liang Wu, Bo Zhen, University of Pennsylvania

    Robyn Sanderson: "What can a billion Milky Way stars tell us about dark matter?"

    Liang Wu: "Therahertz studies on symmetry and topology in quantum materials"

    Bo Zhen: "Topological photonics on the nano scale"

    Host: Joe Kroll

  • Department Colloquium: “A New Era of Science at Jefferson Lab”

    David Rittenhouse Laboratory, A8

    Robert McKeown, Deputy Director for Science, JLAB

    The continuous electron beam accelerator facility at Jefferson Lab, built with advanced superconducting radiofrequency (SRF) technology, provides opportunities to discover fundamental new aspects of the structure of visible matter – protons, neutrons and other states, and of the strong interaction, described by the gauge theory Quantum Chromodynamics.  The recent upgrade of the facility brings new opportunities, not only in the study of hadronic matter, but also in searches for new physics, such as a suite of experiments to search for massive “dark photons”.  This presentation
  • Department Colloquium: “Exploring Symmetry Violation with Free Neutrons”

    David Rittenhouse Laboratory, A8

    Brad Filippone (Cal Tech) hosted by: Christopher Mauger

  • 32nd Primakoff Lecture: "Metamaterials and Topological Mechanics"

    David Rittenhouse Laboratory, A8

    Tom Lubensky (University of Pennsylvania)

    Metamaterials are materials engineered to have a property or properties not found in nature, such as a negative optical index of refraction, one-way light or vibration waves, or exotic elastic behavior.  Advances in materials processing, like 3D printing and laser cutting, over the last 10 to 15 years have made it possible to fabricate metamaterials with made-to-order structure at length scales as short as a micron.

  • Department Colloquium: "Discovering the Highest Energy Neutrinos Using a Radio Phased Array"

    David Rittenhouse Laboratory, A8

    Abigail Vieregg (University of Chicago) hosted by: Mark Devlin

    Ultra-high energy neutrino astronomy sits at the boundary between particle physics and astrophysics. The detection of high energy neutrinos is an important step toward understanding the most energetic cosmic accelerators and would enable tests of fundamental physics at energy scales that cannot easily be achieved on Earth.

  • Department Colloquium: "Results from the Dark Energy Survey"

    David Rittenhouse Laboratory, A8

    Gary Bernstein (University of Pennsylvania)

    The Dark Energy Survey (DES) is a collaboration between UPenn and 15 other institutions in 7 countries to construct and operate a new 500 megapixel CCD camera on the venerable 4-meter Blanco telescope in Chile. Its five-year mission: to survey 1/8 of the night sky in search of clues to the cause of the accelerating expansion of the Universe.

  • Rittenhouse Lecture: "GW170817: Hearing and Seeing a Binary Neutron Star Merger"

    David Rittenhouse Laboratory, A8

    Daniel Holz (Enrico Fermi Institute and Kavli Institute for Cosmology, U of Chicago) hosted by Bhuvnesh Jain

    With the discovery of GW170817 in gravitational waves, and the discovery of an associated short gamma-ray burst, and the discovery of an associated optical afterglow, we have finally entered the era of gravitational-wave multi-messenger astronomy. We will discuss LIGO/Virgo's detection of this binary coalescence, and explore some of the scientific implications, including confirmation of the kilonova model and implications for the origin of gold and platinum in the universe, tests of general relativity, and the first standard siren measurement of the Hubble constant.

  • Physics Department Colloquium: "Orientational Transitions: From Liquid Crystals to Viral Capsids"

    David Rittenhouse Laboratory - A8

    Robijn Bruinsma (UCLA) hosted by Douglas Durian

    Lars Onsager showed in 1948 that there could be a new type of phase transition where a liquid loses rotational symmetry but retains its translational symmetry, unlike the freezing transition where a liquid loses both types of symmetry operations. He proposed that this is what takes place when a liquid becomes a nematic liquid crystal, a material now extensively used in displays.

  • Physics Department Colloquium: "Cal-Bridge and CAMPARE/CHAMP: Engaging Underrepresented Students in Physics and Astronomy"

    David Rittenhouse Laboratory - A8

    Alex Rudolph (Cal Poly Pomona) hosted by: James Aguirre

    The level of participation by underrepresented minority (URM) and female students in physics and astronomy PhD programs is shamefully low (2-4% for URM v. 30% in the general population; 20% for women v. 50% in the general population). I will begin by discussing research into why these participation rates are so low for these groups, highlighting role the physics and general GRE tests play in suppressing diversity in our field, while providing little to no benefit in helping predict long-term success.

  • Physics Department Colloquium: Eye patches: The Evolution of Novel Soft Matter

    David Rittenhouse Laboratory - A8

    Alison Sweeney (U of Penn)

    Life on Earth constitutes the most sophisticated iterations in the known universe of what physicists classify as soft matter.  Research in my group focuses on learning the physical rules of soft matter self-assembly phenomena via the evolutionary processes by which they arose over Earth’s history.  In this view of life as soft matter, evolution, with its own formal rules and algorithms, governs the appearance and diversification of novel forms of soft matter.  The field of soft matter was until very recently restricted to analytical consideration of simpler systems like isotr