News & Events

  • Title: "Imaging Space Plasmas, and Robotic Exploration of the Solar Systems" (Video)

    Abstract: This colloquium takes a virtual tour of the Solar System, mostly as seen by various techniques to image space plasmas.  First, I introduce and define some basic concepts (planetary magnetospheres, definition of a plasma) and introduce you to the Earth's dynamically-changing space environment.  The tour starts with...

  • Title: "The Dark Energy Spectroscopic Instrument (DESI): Creating a 3D Map of the Universe" (Video)

    Abstract:  The Dark Energy Spectroscopic Instrument (DESI) will be installed on the Mayall 4-m telescope at Kitt Peak National Observatory in 2018. Using 5,000 robotic fiber positioners and ten 3-arm spectrographs, DESI will measure the spectra of up to 40 million galaxies and quasars enabling us to create a 3D...

  • Title: "Fabry-Perot Microcavities for Diamond Photonics" (Video)

    Abstract:  Individual defects in crystalline materials can have electronic properties akin to those of isolated trapped atoms or ions.  Like atoms, these defect centers can have spin degrees of freedom and and optical transitions that make them an attractive platform for building quantum information technologies. Their spin states might someday be used to store and manipulate...

  • Title: "Lightning Activity in Winter Storms: A Meteorological and Cloud Microphysical Perspective" (Video)

    Abstract:  The meteorological context, predominant cloud microphysics, electrical charge separation and lightning in winter storms in a wide variety of geographical locations is reviewed. Both similarities and differences between summer and winter conditions are discussed. The observations on the...

  • Title: "Imaging Magnetic Fields at the Event Horizon of a Black Hole" (Video)

    Abstract: Magnetic fields play a central role in the accretion, emission, and outflow near black holes but have never been directly observed in this region. Yet, because linear polarization of the bright synchrotron emission from galactic cores traces these magnetic fields, polarimetric interferometry with the Event Horizon...

  • Title: "The Dawn of Gravitational Wave Astronomy with LIGO" (Video)

    Abstract: On September 14, 2015, the two Advanced detectors of the Laser Interferometer Gravitational Wave Observatory (LIGO) detected gravitational waves from a binary black hole system, opening the era of gravitational wave astronomy. The signal, denoted GW150914, swept in frequency from 35Hz to 250Hz, and had a peak gravitational-wave...

  • Title: "Spin and Magnetism in Small Stars" (Video)

    Abstract:  Main sequence stars with masses below approximately 0.35 solar masses (red dwarfs, or M dwarfs) are fully-convective, and are expected to have a different type of dynamo mechanism than solar-type stars. These low-mass stars are the most common type of star in the galaxy, but a lack of observational constraints at ages beyond 1 Gyr has hampered...

  • Title: "Colliding Cosmologies: Cultural Conflicts and the Future of Astronomy on Mauna Kea" (Video)

    Abstract: Clouds of controversy surround the summit of Mauna Kea on the Big Island of Hawai’i. Astronomers know Mauna Kea as home to world-class observational facilities, such as the W.M. Keck Observatory and Subaru telescope, its clear skies and unobstructed views virtually unmatched...

  • Title: “Testing Bell’s Inequality with Astrophysical Observations” (Video)

    Abstract:  Albert Einstein once dubbed quantum entanglement "spooky action at a distance," and the concept remains one of the starkest examples of how quantum theory differs from our usual intutions about space, time, and matter. Physicists have tested Bell’s inequality experimentally for over four decades, and have always found...

  • Professor Devin Walker recently spoke with Dartmouth News about his research into dark matter. You can read the full interview at Dartmouth News.