Seminars are held on Tuesdays, 3:45-4:45pm in SB 101, unless otherwise noted. Meet at 3:30 in SB 157 for refreshments (refreshments are available even on Tuesdays with no seminar!). See Calvin's Visitor Resources for maps and directions to the Science Building.

Schedules from previous semesters: Spring 2003, Fall 2002, Spring 2002

Atomic Physics Series: September 23 to October 21
These seminars are intended for a general audience with a high-school-level familiarity with physics. However, each presentation will build on the ones before it, so regular attendance is recommended. The speaker, Calvin physics professor Matthew Walhout, has been an active researcher in atomic physics for nearly fifteen years. He collaborates with undergraduate students in his lab at Calvin and with other scientists in the U.S. and France.

• September 23: A Quantum Physics Primer for Everyone
  An introduction to atoms and light, basic ideas of quantum mechanics, and some recent developments that have turned the field of atomic physics inside out.
• September 30: Getting a Handle on Atomic Motion
  How the quantum structure inside atoms allows us to exert forces from the outside. Special emphasis on the quantum behavior of atoms in magnetic fields.
• October 7: Laser Cooling and Trapping of Neutral Atoms
  Slow atomic beams, optical molasses, neutral atom traps, and other developments that led to the 1997 Nobel Prize in Physics.
• October 14: Bose-Einstein Condensation of Dilute Atomic Gases
  An introduction to concepts related to this new, quantum form of matter and an overview of the developments that led to the 2001 Nobel Prize in Physics.
• October 21: Spinning Giant Helium Molecules with Light Thread
  Professor Walhout’s sabbatical work to discover “the weakest link” between two helium atoms. Laser excitation of ultracold helium atoms produces exotic molecules and yields measurements of key parameters related to atomic structure and BEC dynamics.

November 11:  Picturing Other Worlds: Explorations in Extrasolar Planet Imaging, Andrew Vanden Heuvel, senior
Over 100 planets have been discovered outside of our solar system in the past 10 yeas. All of these planets were discovered by indirect means. No picture has ever been taken of an extrasolar planet. The technology to achieve this difficult task is beginning to reach maturity. Andrew spent the summer ar the Harvard-Smithsonian Center for Astrophysics attempting to create a coronagraphic stop capable of imaging an extrasolar planet. This work was the first effort at creating such a stop and was met with limited but promising success.

November 18:  What is Faraday Rotation, and What Is It Good For?
John VanderWeide (junior), Chris Walker (junior), and Prof. David Van Baak
Since a discovery by Michael Faraday in 1845, it's been known that magnetism affects light. In this seminar you'll see how and why this sort of interaction occurs, and how and why a research team at Calvin last summer investigated the interaction of laser light with rubidium atoms immersed in a magnetic field.

November 25: A Sharper Image of Radio Emission from Saturn
Elise Crull (junior) and Prof. Larry Molnar.
The spatial distribution of the trillions of particles composing Saturn's rings can help us understand the processes by which macroscopic objects are created. Specifically, it can teach us about the formation of planets, a topic on which surprisingly little is known. We have produced a radio image of Saturn's rings more sensitive than any previous image. Analysis of the image reveals new evidence for wake structure in the rings, as well as interesting structure on the planet itself.

December 2: 2-D Cellular Automata Simulations of Lipid Phase Transitions Mark Gordon '03
Lipids are the fundamental building blocks of cell membranes and have a number of fascinating properties. As lipids membranes are heated, they often curl up in cylinders that stack hexagonally. This structural transition is interesting in its own right and is biologically relevant. We used simple cellular automata model to simulate this transition and were able to duplicate some of the significant features of the phase transformation.

December 9: Superheating and Supercooling of Alkanes and Lipids
Peter Cook and Mitch Machiela (juniors), students of Prof. Harper
Over the past summer, we have continued to refine our laser light scattering apparatus and have revived the physics DSC (Differential Scanning Calorimeter). In order to properly use these devices to measure superheating and supercooling, it is necessary to account for instrumental lag and error. We present a number of calibration measurements for the laser light scattering apparatus and some initial measurements made using the DSC. Though a number of issues have been resolved, some open questions still remain.