Past Events

  • 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

  • Department Colloquium: "Simulating the self-assembly of nano-puzzles"

    David Rittenhouse Laboratory, A8

    Daan Frenkel (Cambridge University) hosted by Tom Lubensky

    A holy grail of nano-technology is to create truly complex, multi-component structures by self-assembly. Most self-assembly has focused on the creation of "structural complexity." In my talk, I will discuss "Addressable Complexity": the creation of structures that contain hundreds or thousands of distinct building blocks that all must find their place in a 3D structure. Recent experiments have demonstrated the feasibility of making such structures. Simulation and theory yield surprising insights that can inform the design of novel structures and materials [1].

  • Rittenhouse Lecture: "Early Results from Juno's Exploration of Jupiter"

    David Rittenhouse Laboratory, A8

    Scott Bolton, Southwest Research Institute

    NASA's Juno mission to Jupiter launched in 2011 and arrived at Jupiter on July 4, 2016.  Juno's scientific objectives include the study of Jupiter's interior, atmosphere and magnetosphere with the goal of understanding Jupiter's origin, formation and evolution.  As the largest and most massive planet in our solar system, Jupiter offers unique insight in the history of our solar system and how planetary systems in general form and evolve.  Juno's multidisciplinary study of Jupiter constrains the interior structure and atmospheric composition, investigates Jupiter's de

  • Department Colloquium: "Results from the New Horizons Flyby of Pluto"

    David Rittenhouse Laboratory, A8

    Marc Buie (Southwest Research Institute) hosted by Mariangela Bernardi

    July 2015 saw the culmination of decades of work to get a detailed look at a distant and intriguing world.  As of late 2016, the transmission of all data from the encounter was completed and the project is now turning its attention to the upcoming extended mission flyby of 2014MU69 on 2019 Jan 1.  The encounter was crucial for pinning down seemingly simple quantities such as size and albedo but opened the door to much more in-depth studies of the origin and evolution of Pluto and its constraints on the history of our solar system.