Radiations

Department of Physics and Astronomy

Carleton College

April 1-7, 2001

 Weekly Calendar

Friday, April 6 , 12-1:00, Sevy CTR, Physics Table , The Physics Table weekly meeting is an opportunity for students and staff to get together for lunch. Meet on 3^rd floor Olin at 11:50 a.m. for the walk to Sevy, or join us there at noon. If you are not on board, please bring your lunch. Everyone is welcome!

Friday, April 6 , 1:10-2:20, Olin 141, P123 "What Physicists Do" , "Cool Science: Using the Physics and Chemistry of Materials to Make More Efficient Refrigeration Devices, " Kristin Poduska (York University) Imagine a small, noiseless refrigerator that directly converts electricity to cooling, without the use of freon coolants or heavy compressors. In fact, such solid state thermoelectric devices are already on the market for use in computer microprocessor cooling and portable picnic coolers. Unfortunately, these devices are not yet efficient enough to replace conventional cooling technologies entirely. The primary challenge in improving device efficiency lies in developing new materials with a favorable balance of electrical and thermal transport properties. Strategies for creating such new materials involve three steps: synthesis, structural characterization, and physical property evaluation. Kristin will describe the approaches she have used to explore new metals and semiconductors for potential thermoelectric cooling applications. Additionally, she will discuss the relevance of such studies in the broader context of relating the structural chemistry of a material to its physical properties.

Kristin has just begun her position at York U. after receiving a Ph.D. from Cornell and a B.A. from Carleton. Join the speaker for lunch in Sevy Corner Tea Room from 12 to 1 PM beforehand, and for snacks in the Physics Lounge on 2^nd Olin afterwards

Friday, April 6, Goodsell Observatory, Public Open House 8:00-10:00pm, Come look through the observatory’s two historic telescopes. Dress appropriately as the domes are not heated. Canceled if cloudy. For more information call Claire at 646-5719.

COMPS PRESENTATION TALKS

Copies of the introductory papers are available for your review in Second Olin Lounge

Monday, April 2, 3:10-4:20, Olin 04, Emily Baker, "Gravitational Lensing" Light and matter. Our physics education has led to a great familiarity with these two types of stuff that make up our universe. Physics also leads us to explore the interactions between different types of stuff in order to gain a better understanding of the universe. One of the fascinating interactions between matter and light results is gravitational lensing.

Wednesday, April 4 , 3:10-4:20, Olin 04, Carl Tape, "Oceanic Tides: A Response to Differential Force throughout the Earth's History" Have you ever likened the concept of the tides to "black magic," as one physicist did? In my talk I hope to explain the origin of oceanic tides, beginning with the concept of differential force. I'll begin with the simplest scenario -- such as a rod in free fall toward the Earth -- and progress to the Earth-moon system, eventually considering the ocean covering, the Earth's rotation, and the effects of the sun. We'll look at tides at a global scale, an ocean scale, and a coastal scale. Lastly, we'll see what sedimentary rocks can tell us about the evolution of the Earth-moon system.

CONGRATULATIONS to Jennifer Birriel, our visiting professor of physics and astronomy, received a research grant from the American Astronomical Society in support of her astronomical studies of planetary nebulae.