Friday, September 14, 2018 - 3:10pm to 4:00pm  ·  Colloquium
Prof. Fran Bagenal, Department of Astrophysical and Planetary Sciences and Laboratory for Atmospheric and Space Physics, University of Colorado

For the past 25 years or so I have been digging into the demographics of our field. I guess it is the scientist in me. But I also find that the numbers can challenge our assumptions about what is shaping the demographics of our field. In this regard, it is useful to look at the demographics of scientific fields in different countries. Which country would you guess to have the highest percentage of PhDs in physics awarded to women? It’s probably not a country that comes to mind. Then there is the usual assumption that the numbers must be getting better with time.

Friday, April 27, 2018 - 3:10pm  ·  Colloquium
Dr. Ben Chandran, University of New Hampshire

Beginning with Parker's 1958 paper predicting a supersonic outflow from the Sun, theoretical investigations and spacecraft measurements have led to considerable progress in our understanding of the solar wind. In this talk, I will review one of the leading models for the solar wind's origin and discuss what this model may tell us about more distant astrophysical outflows. In this model, the solar wind is powered primarily by Alfven waves, which are like waves on a string, where magnetic field lines play the role of the string.

Friday, April 6, 2018 - 3:10pm to 4:00pm  ·  Colloquium
Victor Watson Brar, University of Wisconsin - Madison

Abstract: Graphene, an atomically thin sheet of carbon atoms, is a two dimensional semi-metal in which the electrons behave as massless Fermions. Because it is extremely thin and has a low carrier density, the local electronic structure of graphene can be strongly modified by impurities found either in the nearby environment, or introduced via intentional doping. This talk will discuss several impurity related phenomena that are observed in graphene and how they can modify the macroscopic properties that are observed in graphene devices.

Friday, March 23, 2018 - 3:10pm to 4:00pm  ·  Colloquium
Dr. Chanda Prescod-Weinstein, Department of Physics / Dark Universe Science Center, University of Washington, Seattle

Abstract: Last year, student protestors at Bates College posed a powerful question: "What radical decisions is Bates making today to put the College 100 years ahead of our peer schools?" I believe we should be asking this question everywhere, especially at our public universities. In my talk,I respond with possible answers in the context of science, technology, engineering, and mathematics, fields where minoritized students -- and in tandem, faculty -- are especially marginalized in academia.

Friday, March 2, 2018 - 3:10pm to 4:00pm  ·  Colloquium
Francois Foucart, University of New Hampshire

Abstract: The first few detections of gravitational waves by the LIGO and Virgo observatories have opened an entire new way for us to study the Universe. The brightest gravitational wave signals are powered by collisions of the most compact astrophysical objects known to exist: black holes and neutron stars. In such events, two objects more massive than the sun merge in just a few milliseconds, releasing a tremendous amount of energy.

Wednesday, February 28, 2018 - 4:10pm to 5:00pm  ·  Colloquium
Dr. Joshua Schlieder, Univ. of Maryland and NASA Goddard Space Flight Center

Abstract: Over the last two decades, our knowledge of planetary systems has expanded beyond our solar system to thousands of planets orbiting thousands of stars. The first exoplanet discoveries were driven by new and novel techniques that have matured to reveal an unexpected diversity of distant worlds. I will review the observational techniques used to detect exoplanets and detail the often surprising first discoveries. We now know that planets are common, and nearly every star in the Galaxy hosts at least one.

Monday, February 5, 2018 - 3:10pm to 4:00pm  ·  Colloquium
Dr. Regina Caputo

Abstract: The era of precision cosmology revealed that 80% of the matter in the universe is non-luminous, or dark. The nature of dark matter is crucial to our understanding of the structure and evolution of the universe after the big bang. One promising dark matter candidate, motivated by both particle- and astrophysics, is the Weakly Interacting Massive Particle (WIMP). The detection of this elusive particle requires a multi-pronged approach. I will present results from searches for WIMPs using high-energy gamma-rays from the Fermi Gamma-Ray Space Telescope.

Monday, January 29, 2018 - 3:10pm to 4:00pm  ·  Colloquium
Dr. Nahee Park, Wisconsin IceCube Particle Astrophysics Center

Abstract: Cosmic rays, high energy particles originating from outside of the solar system, are believed to be dominated by particles from our Galaxy at least up to the energy of 10^15 eV. Since the discovery of these particles in 1912, the origin, acceleration and propagation of these high energy particles have remained as century old questions. In the last few years, we have seen the most precise measurements of cosmic rays from space-borne experiments.

Thursday, January 25, 2018 - 4:10pm to 5:00pm  ·  Colloquium
Dr. Jaclyn Sanders, Syracuse University

Abstract: Over the past two years, the Laser Interferometer Gravitational-Wave Observatory (LIGO) has made the first detections of gravitational waves from compact binary mergers. These observations have already allowed novel tests of strong-field general relativity and sparked a multi-messenger observing campaign that resulted in the first observation of a kilo-nova across the electromagnetic spectrum. All of these achievements hinge on the performance of the detectors themselves.

Monday, January 22, 2018 - 3:10pm to 4:00pm  ·  Colloquium
Dr. Fabian Kislat, Washington University

Abstract: Since the discovery of the first extra-solar X-ray source, Scorpius X-1, by Giacconi and collaborators in 1962, X-ray imaging, spectroscopic and timing observations have significantly deepened our understanding of the most extreme objects in the universe. In the innermost regions of accreting blackholes, we can observe matter in the strongest gravitational fields in the universe. Neutron stars represent the densest known form of matter in the universe and are the source of the strongest known magnetic fields.