Events at Physics |
Events on Tuesday, February 12th, 2008
- Chaos & Complex Systems Seminar
- Electoral dynamics in the 2008 presidential primaries
- Time: 12:05 pm
- Place: 4274 Chamberlin Hall
- Speaker: Charles Franklin, Political Science
- Abstract: This presentation is an anecdotal treatment about ways of seeing the world, ways of looking beyond the visual scene to see what is behind it. It is not based on any scientific paradigm and I make no claim for either great insight or originality. It seems to me, however, to touch on a part of the creative process for a scientist. One of the ways of seeing that I will discuss is that of looking for interesting questions suggested by the visual scene. Since the questions come out of the background peculiar to the viewer, my examples will necessarily be personal. But I hope to illustrate some ways of seeing the world around us that others can adapt to their own particular backgrounds, and, perhaps cultivate.
- Plasma Seminar--Special Day
- Ion Pickup and Acceleration in Magnetic Reconnection Exhausts
- Time: 2:30 pm
- Place: 4274 Chamberlin Hall (coffee at 3:30 pm)
- Speaker: Jim Drake, University of Maryland
- Astronomy Colloquium
- The Evolution of the Earliest Stages of Low-mass Star Formation
- Time: 3:45 pm
- Place: 6515 Sterling Hall (coffee at 3:30 pm)
- Speaker: Yancy Shirley, University of Arizona
- Abstract: Low-mass starless cores are the incipient phase of low-mass star formation. They are observed via submillimeter dust continuum and dense gas molecular lines, they typically contain a few solar masses, they have sizes of approximately 0.1 pc, and they may form one or a few low-mass (M ~ 1 M_sun) stars. It is crucial to understand the formation and evolution of these objects to set the initial conditions for protostar and disk formation. Theoretically, the basic core formation and evolution process is still debated between a turbulent-dominated or ambi-polar diffusion-dominated model. Observationally, a fundamental challenge is to determine the evolutionary state of a starless core. I shall review the basic processes that are used to develop a chemical evolutionary sequence for low-mass starless cores and that breaks currently observed degeneracies in thephysical structure of the cores. I shall highlight results from the Arizona Radio Observatory-Green Bank Telescope Survey which has mapped a sample of 25 nearby starless cores in dust continuum emission and 10 molecular transitions.