Events at Physics |
Events During the Week of September 1st through September 8th, 2013
Monday, September 2nd, 2013
- No events scheduled
Tuesday, September 3rd, 2013
- Chaos & Complex Systems Seminar
- he taxonomy of fuels
- Time: 12:05 pm
- Place: 4274 Chamberlin
- Speaker: Jim Blair, Milton and Edgewood College
- Abstract: *Internal and external combustion engines<br>
*Piston engines vs gas turbines and the fuel requirements for both<br>
*Additives: What is octane number, and the pros and cons of various ways to increase it: Tetraethyl lead, MTBE, aromatics, and alcohols<br>
*Did cumene win the Battle for Britain?<br>
*How the source of lead contamination can be determined from the unusual isotopic properties of that element.<br>
*The tradeoff between the different kinds of pollution emitted by internal combustion motors<br>
*The pros and cons of ethanol as a fuel for cars<br>
*Why it is easier to make bio-diesel and bio-jet fuel than bio-gasoline<br>
*Why a modern jet fighter would have been useful in WW I, but a WW II Spitfire or P-51 Mustang would not have been.<br>
- Host: Clint Sprott
Wednesday, September 4th, 2013
- Department Meeting
- Time: 12:15 pm
- Place: 5310 Chamberlin Hall
Thursday, September 5th, 2013
- R. G. Herb Condensed Matter Seminar
- Random Matrix Approach to Understand the Statistical Properties of Complex Wave Scattering Systems
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Jen-Hao Yeh, University of Maryland
- Abstract: There is great interest in the quantum/wave properties of systems that show chaos in the classical (short wavelength, or ray) limit. These wave chaotic systems appear in many contexts: nuclear physics, acoustics, two-dimensional quantum dots, and electromagnetic enclosures. Initiated by the need to understand the energy levels of complicated nuclei, random matrix theory (RMT) has been applied to successfully predict universal properties of these complicated wave-scattering systems through the statistical description of their eigenvalues, eigenfunctions, impedance matrices, and scattering matrices. For understanding the properties of practical systems, researchers at Maryland have developed the random coupling model (RCM) to offer a complete statistical model which utilizes a simple additive formula in terms of impedance matrices to combine the predictions of RMT and the nonuniversal system-specific features in practical systems. We have carried out experimental tests of the random coupling model in microwave cavities, including a superconducting microwave cavity acting as a low loss environment. The results demonstrate the nonuniversal features, such as the radiation impedance and the short orbits, and the universal fluctuations in wave properties, such as the scattering matrix elements and the impedance matrix elements, of complex wave scattering systems.
- Host: McDermott
- Special Talk
- Massive Galaxies in the Early Universe: New Insights into Galaxy Formation and Evolution
- Time: 3:30 pm - 5:00 pm
- Place: 4421 Sterling Hall
- Speaker: Danilo Marchesini, Tufts University
- Abstract: In the past decade, our understanding of the galaxy population in the first 4 billion years of cosmic history (z>2) has improved significantly, thanks to the increasing ability to construct comprehensive snapshots (in time) from z=4 (when the universe was ~1.5 billion years old) to z=2. I will summarize our current knowledge of the (massive) galaxy population at z=2-4, with an emphasis on the results from the NEWFIRM Medium-Band Survey, a large NOAO/Yale program which uses medium band-width filters in the near-infrared to obtain well-sampled spectral energy distributions and high-quality photometric redshifts at z>1.5 over 0.5 square degree. I will present recent results from the UltraVISTA and NMBS-II, and preliminary results from on-going follow-up spectroscopic programs.
- Host: Prof Elena D'Onghia
Friday, September 6th, 2013
- Physics Department Colloquium
- Memories of John Hasbrouck Van Vleck
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall (coffee at 4:30 pm)
- Speaker: Raymond L. Orbach, University of Texas at Austin
- Abstract: "John Hasbrouck Van Vleck is justly considered to be the father of modern magnetism. In an obituary notice, Comptes Rendu said of him: Depuis Willard Gibbs, mort en 1903, les Etats Unis n'avaient pas eu de representant de la physique theorique aussi eminent que Van Vleck; il a ete le maitre a penser de la jeune physique theorique americaine.' Few would disagree with this judgement... There is hardly any aspect of research in magnetism to which his work has not made an important contribution." [B. Bleaney, Biographical Memoirs of Fellows of the Royal Society 28, 627 (1982)] This talk will explore the basis of these assessments, beginning with the genealogy of the "Ancestry and Descendants of Tielman Van Vleck" [by his aunt, Jane Van Vleck], his undergraduate experience at the University of Wisconsin, his doctorate at Harvard, an Assistant Professorship at the University of Minnesota, his marriage to Abigail Pearson, his move to the University of Wisconsin as Professor of Physics, and finally to Harvard where he held the Hollis Professorship of Mathematics and Natural Philosophy from 1951 to his retirement in 1969. His immense contributions to science and society will be reviewed, as well as his wit and charm, and of course his love affair with railroad and airline schedules. Finally, his wonderful mentorship of so many of us will be recalled with love and affection.
- Host: Lin