Events at Physics |
Events During the Week of March 9th through March 16th, 2008
Monday, March 10th, 2008
- Galaxies Lunch!
- Loose Ends in Cosmic Rays
- Time: 12:00 pm
- Place: 6515 Sterling
- Speaker: Pasquale Blasi, Arcetri & Fermliab
- Abstract: I will describe how cosmic rays must modify the environment in which they are accelerated and how this leads to predict that the the end of the galactic cosmic ray spectrum should be around 1017 eV and be made of heavy nuclei. I will then describe how the galactic spectrum joins the emerging extragalactic cosmic ray spectrum, and how the global ultra high energy cosmic ray pectrum eventually ends.
- Host: Montaruli
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Field Error Effects on Tokamak Plasmas
- Time: 12:05 pm
- Place: 2241 Chamberlin Hall
- Speaker: Andrew Cole, UW-Madison, Department of Engineering Physics
- High Energy Seminar
- New Physics Search in Tau Decays
- Time: 4:00 pm
- Place: 4274 Chamberlin (coffee & cookies at 3:30 pm)
- Speaker: Sanjay Swain, Stanford Linear Accelerator Center
- Medical Physics Seminar
- TBD
- Time: 4:00 pm
- Place: 1345 Health Science Learning Center (refreshments will be served)
- Speaker: Sheridan Griffin-Meltsner, Assistant Professor of Medical Physics and Radiology, UW-School of Medicine and Public Health
Tuesday, March 11th, 2008
- Chaos & Complex Systems Seminar
- Technological change and the global energy system
- Time: 12:05 pm
- Place: 4274 Chamberlin Hall
- Speaker: Gregory Nemet, La Follette School of Public Affairs
- Abstract: Meaningfully addressing the large scale challenges associated with the way we use and consume energy -- including security of supply, air pollution, and climate change -- will require transformation of the global energy system. Designing policies to encourage this change in societally beneficial directions is plagued by an array of uncertainties. In particular, attempts to model optimal policy design reach vastly different normative conclusions depending on assumptions about the expected rate of technical change and the extent to which government actions can affect it. Empirical work on parameterizing technical change is plagued by concerns about the inherent stochasticity of the process of innovation and the idiosyncrasies of individual technologies. Still, the search for useful models of technological change continues. This talk presents recent efforts to model the process of technological change in low-carbon energy technologies.
- Astronomy Colloquium
- Dark Matter Substructure in the Milky Way
- Time: 3:30 pm
- Place: 6515 Sterling Hall
- Speaker: Mike Kuhlen, Institute for Advanced Study at Princeton
- Abstract: It is a clear unique prediction of the cold dark matter paradigm of cosmological structure formation that galaxies form hierarchically and are embedded in massive, extended dark halos teeming with self-bound substructure or "subhalos". The amount and spatial distribution of subhalos around their host provide unique information and clues on the galaxy assembly process and the nature of the dark matter. I will present results from the "Via Lactea" simulations of Galactic CDM substructure, focusing in particular on the possibility of directly observing it through the detection of gamma-rays from DM annihilations in the centers of subhalos.
Wednesday, March 12th, 2008
- No events scheduled
Thursday, March 13th, 2008
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Finding Clusters of Galaxies Using the South Pole Telescope
- Time: 4:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Bradford Benson, UC Berkeley
- Abstract: The South Pole Telescope (SPT) is a 10 meter diameter millimeter wavelength telescope located at the South Pole. It's primary science project is to conduct a 4000 square degree survey to find clusters of galaxies via the Sunyaev-Zel'dovich (SZ) effect, the inverse Compton scattering of the CMB off of hot intra-cluster gas. An SZ survey of this size should find several thousand galaxy clusters, which can in principle place interesting constraints on the dark energy density and equation of state, as well as produce a host of other secondary science results (e.g. - measurements of small scale primary and other secondary CMB anisotropies, gravitational lensing of the CMB, point source catalogs at millimeter wavelengths, ...). To achieve this required over an order of magnitude increase in mapping speed over previous generation millimeter wavelength receivers, and was accomplished with the development of a 960 element large format bolometer array. I will discuss the design and construction of the SPT receiver, SPT's current project status, which recently began its second year of observations, and future plans for the SPT.
Friday, March 14th, 2008
- Physics Department Colloquium
- The Quest for Spinning Glue
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee at 3:30 pm)
- Speaker: Bernd Surrow, MIT
- Abstract: Scattering experiments have played an important role in our current understanding of the world around us. This field aims to answer profound questions such as the origin of the proton mass and spin. Numerous experimental results contributed in the last decades to the test and exploration of the field theory among quarks and gluons known as Quantum Chromodynamics (QCD). In contrast to physics at a large distance scales (e.g. atomic, molecular and nuclear), the mass of the proton originates predominantly in the interactions among its constituents, rather than in the bare masses of the constituents themselves. The strong force that confine quarks inside the proton lead to abundant gluons and quark-antiquark pairs. Those are crucial silent partners in matter, making dominant contributions to the mass of the visible universe. It is not yet completely known how these silent partners also make critical contributions to fundamental properties of the proton other than mass such as the spin of the proton. The high-energy spin physics program at the RHIC facility at Brookhaven National Laboratory focuses on the collision of high-energy polarized protons to gain a deeper understanding of the spin structure and dynamics of the proton, in particular to provide better insight into the role of gluons to make up the spin of the proton. After an introduction into this field, I will review experimental results for gluons making up a large contribution to the proton followed by first results obtained on the quest for spinning glue. I will conclude with an overview of planned measurements in the future.
- Host: Wesley Smith