Colloquium: Viscosity, Quark Gluon Plasma, and String Theory

Viscosity, quark gluon plasma, and string theory

Viscosity is a very old concept which was introduced to physics by Navier in the 19th century. However, in strongly coupled systems, viscosity is difficult to compute from first principle. In this talk I will describe some recent surprising developments in string theory which allow one to compute the viscosity for a class of strongly interacting quantum fluids not too dissimilar to the quark gluon plasma. I will describe efforts to measure the viscosity and other physical properties of the quark gluon plasma created in relativistic heavy ion collisions.

Cosmic Linear Accelerators: Extreme Reconnection and other Surprises from the Crab Nebula

The unexpected discovery of gamma-ray flares from the Crab Nebula may have surprising implications for plasma astrophysics. Standard particle acceleration mechanisms cannot account for the energies of the flaring photons. Instead, these observations point toward an acceleration process involving rapid destruction of magnetic field through reconnection. I will discuss the extreme particle acceleration process that may lead to the flares, and the likely role of current-driven instabilities in triggering reconnection in the Crab and elsewhere.

Colloquium: Glimpsing Color in the World of Black and White

Glimpsing color in a world of black and white

Protons, neutrons and all the many other strongly interacting subnuclear particles, known as hadrons, are made of quarks and gluons. These fundamental constituents are held together by a color force described by quantum chromodynamics (QCD). A detailed understanding of how the strong coupling regime of QCD, which is responsible for confinement and dynamical chiral symmetry breaking, determines the spectrum and structure of hadrons will be outlined. Such studies, both experimental and theoretical, color in the picture of strong dynamics. What we know now and the glimpses to come from accelerator facilities like that at Jefferson Lab will be described.

Higgs Discovery: Implications for Particle Physics - 2 Nov. 2012

The LHC has recently discovered a Higgs-like resonance with a mass of about 125 GeV. It may be the missing element of the so-called Standard Model of particle physics. This model was proposed a few decades ago, and, after the inclusion of neutrino masses, describes in an accurate way all measured observables not involving gravity. We shall discuss what are the possible implications of the Higgs Discovery for particle physics and, in particular, for theoretical and experimental physics High Energy Physics in the coming years.

New Faculty 2012: Meet Renbin Yan

The Department of Physics & Astronomy is excited to welcome professor Renbin Yan to its faculty!

Professor Yan has been interested in the cosmos since childhood, and joins us this fall to continue his research on star formation. His research seeks to understand why some galaxies no longer produce stars. This podcast is part of a series highlighting the new faculty members who joined the College of Arts and Sciences in the fall 2012 semester, and was produced by Cheyenne Hohman


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From Voids to Clusters: Gas and Galaxy Evolution in the Local Universe - 12 Oct. 2012

Our understanding of the formation and evolution of galaxies and their large scale structure has advanced enormously over the last decade, thanks to an impressive synergy between theoretical and observational efforts. While the growth of the dark matter component seems well understood, the physics of the gas, during its accretion, removal and/or depletion is less well understood. Increasingly large scale optical surveys are tracing out the cosmic web of filaments and voids. Mathematical tools have been developed to describe these structures and to identify galaxies located in specific environments. HI imaging surveys begin to answer the question: how do galaxies get and lose their gas? The best evidence for ongoing gas accretion is found in the lowest density environments, while removal of gas in the highest density environments stops star formation and reddens the galaxies. Speaker: Jacquiline van Gorkom, Columbia University

Watching the Transit of Venus at UK Arboretum

Stargazing is typically reserved for after sundown, but what if you want to look at the biggest star in the sky? On June 5th, 2012, the planet Venus was visible by day – traveling in front of the sun! This is called the Transit of Venus, and is a rare astronomical event. A few hundred people gathered at the UK Arboretum to view the transit of Venus through special telescopes that allow safe observation of solar activity. In this podcast, we went to the Arboretum to talk to participants and Tim Knauer, the director of the MacAdam Student Observatory on UK's campus. The viewing was sponsored by the UK Physics & Astronomy Department and was done in conjunction with the Kentucky SkyTalks series. 











This podcast was produced by Cheyenne Hohman

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The Formation and Evolution of Galaxies Group: Isaac Shlosman

At UK, the Formation and Evolution of Galaxies Group is a team of graduate students, post-doctoral fellows, and faculty, who use the University's Dell Cluster supercomputer to predict and simulate the galactic mechanics of the early universe.

In this podcast, we talk to Isaac Shlosman, the group's faculty lead, about an observational discovery made in the fall of 2011, what will replace the Hubble, and how dark matter forms the back-bone of the universe.

This podcast was produced by Stephen Gordinier.

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Dean's Channel: Figuring Physics with Mike Cavagnero

In part two of the Dean's interview with Mike Cavagnero, the Chair of Physics and Astronomy discusses the role of the department on campus and the possibilities and excitement of where the discipline may be headed.


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