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

    01:32:01

    from UK College of Arts & Sciences / Added

    36 Plays / / 0 Comments

    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

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    • Philip Phillips

      32:09

      from UK College of Arts & Sciences / Added

      12 Plays / / 0 Comments

      Philip Phillips presenting at Great Lakes String 2013

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      • Dean's Channel: Figuring Physics with Mike Cavagnero

        07:24

        from UK College of Arts & Sciences / Added

        83 Plays / / 0 Comments

        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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        • Emil Martinec

          31:56

          from UK College of Arts & Sciences / Added

          11 Plays / / 0 Comments

          Emil Martinec presenting at Great Lakes String 2013

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          • Colloquium: Organic (Plastic!) Semiconductors

            01:16:31

            from UK College of Arts & Sciences / Added

            40 Plays / / 0 Comments

            Organic materials are finding an increasing number of possible niches in electronic devices. I will give a very brief overview of some of the present and anticipated applications of organic semiconductors and issues in understanding their application. I will then discuss some of our recent experiments on using infrared electro-optics to measure the mobility of charges in organic thin-film transistors and conclude by describing our ongoing experiments to measure the thermal conductivities of organic semiconductors, important for possible applications as thermoelectric power generators. Speaker / Presenter: Joseph Brill, Dept of Physics & Astronomy, University of Kentucky

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            • Designing energy and climate security in different regions of the world

              01:26:48

              from UK College of Arts & Sciences / Added

              10 Plays / / 0 Comments

              Dr. Rajan Gupta Los Alamos National Labs Spectacular developments in technology and resource exploitation have provided 2-3 billion people with unprecedented lifestyles and opportunities in the twentieth century. On the energy front, this has largely been achieved using inexpensive fossil fuels-- coal, oil and natural gas. The real costs of burning fossil fuels, many of which are hidden and long-term, have been environmental. Today, all species and nature, are being stressed at unprecedented levels and face conditions that have an increasing probability of resulting in catastrophes. Providing the same opportunities to nine or ten billion people will require 2-3 times current energy resources even with business-as-usual anticipated gains in efficiency. There is little doubt that, globally, we have the resources (100 more years of fossil fuels) and the technology to use fossil-fuels ever more cleanly so that the impacts on the environment are smaller and localized. Unfortunately, the emissions of green house gases and their contributions to climate change mandate we transform from the existing successful fossil-fuel system to zero-carbon emission systems. This talk will examine energy resources in different regions of the world and address the issue of whether these resources can provide energy security for the next fourty years. I will next examine how countries with enough resources (fossil, nuclear, hydroelectric) can reduce their carbon footprint in the power sector. I will then discuss the conditions needed to integrate large-scale solar and wind resources to create sustainable systems. Finally, I will identify areas which lack adequate reserves of fossil fuels and how they can address the simultaneous challenges of energy and climate security.

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              • Science Policy in America

                01:09:24

                from UK College of Arts & Sciences / Added

                11 Plays / / 0 Comments

                Dr. Tyler Glembo The American Physical Society Science Policy in America Fundamental scientific research, as a majority federally funded initiative, is becoming more deeply embedded in politics. Since the end of the Space Race, funding of basic physical sciences research as a percent GDP has continuously declined, indicating that policy makers see funding scientific research as less of a priority than they once did. Indeed, a lack of understanding about both science and how science is done amongst members of Congress has led to both reduced prioritization and also to misguided attempts at regulation, such as making peer review a public process and considering Congressional oversight for specific grants. Here we will examine a few current issues in science policy and the need for physicists to effectively weigh in on such policy issues. We will also consider the positive or negative effects such public engagement may have on our scientific careers and ways in which you can get involved.

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                • Quantum Gravity with Anisotropic Scaling and the Multicritical Universe

                  01:21:23

                  from UK College of Arts & Sciences / Added

                  18 Plays / / 0 Comments

                  Dr. Petr Horava University of California, Berkeley The problem of understanding how gravity fits together with other fundamental interactions of matter has been at the forefront of theoretical research for many decades, leading to the rich framework of string theory and M-theory. In this framework, many fundamental questions are being resolved, but many remain quite mysterious, suggesting that some novel concepts may be needed. I review the recent concept of multicritical gravity with Lifshitz-type anisotropic scaling, and its applications in areas ranging from particle phenomenology beyond the standard model to non-relativistic versions of the AdS/CFT correspondence.

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                  • Hidden Interactions of Quarks

                    01:00:30

                    from UK College of Arts & Sciences / Added

                    8 Plays / / 0 Comments

                    Dr. Bogdan Dobrescu FNAL The quarks feel all five types of boson-mediated interactions: electromagnetic, strong, weak, Higgs and gravitational. In this talk I will discuss theoretical and experimental constraints on hypothetical new interactions among quarks. Interactions of this type can be hidden if they have a very short range, or if they are very weak, or by other mechanisms such as momentum-dependent couplings. A related question is how strongly can quarks interact with dark matter.

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                    • Observation of the thermal Casimir effect and new limits on non-Newtonian forces in the micrometer range

                      01:09:08

                      from UK College of Arts & Sciences / Added

                      40 Plays / / 0 Comments

                      Quantum theory predicts the existence of the Casimir force between macroscopic bodies, a force arising from the zero-point energy of electromagnetic field modes around them. I will report the experimental observation of the thermal Casimir force between two gold plates, due to thermal rather than quantum fluctuations of the electromagnetic field at room-temperature. The thermal Casimir force dominates over the quantum force for separations greater than a micrometer. We use our measurements to place new upper bounds on short-range exotic forces, arising, for example, in quantum gravity theories with extra dimensions.

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