Calendar



Spring 2003


Week 1 - January 13 - 17

Monday, January 13

First day of classes for Spring Semester.

Friday, January 17, 12PM - 1PM

Physics Lunch. (Not the usual location, but close!) Bring your lunch tray to Lower Dempsey to join the department for stimulating conversation.

Friday, January 17, 3:10PM - 4PM

Physics Colloquium, Franklin Miller, Jr. Lecture Hall (RBH 109). Art Smith, Department of Physics, Ohio University "Steps in the Direction of a Spintronic Future" Abstract: As future electronic devices get smaller and smaller, they are predicted to make extensive use not only of the charge, but also of the spin of the electron (spintronics) and thus to achieve higher speeds and increased multifunctionality.  For this to become a reality, new materials need to be explored, and methods of measuring spin at ultra-small length scales need to be studied.  One possible class of spintronic materials are the nitrides. We have recently been investigating several types of nitride systems, including Mn_xN_y and Mn_xGa_(1-x)N.  I will describe some of our recent results, and in particular I will discuss  the relatively new method of spin-polarized scanning tunneling microscopy, which we have successfully used to image the surface spin structure of antiferromagnetic Mn_3N_2 with atomic-scale resolution. Reception to follow in Hayes Hall Lobby.


Week 2 - January 20 - 24

Friday, January 24, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.

Friday, January 24, 3:10PM - 4PM

Physics Colloquium, Franklin Miller, Jr. Lecture Hall (RBH 109). Yumi Ijiri, Department of Physics and Astronomy, Oberlin College "Upgrading Your Hard Drive: Understanding the Magnetism of Nanoscale Particles and Films." Abstract: Magnetic materials play an important role in a variety of technological applications, particularly related to data storage. Dr. Ijiri's talk will decribe how nanometer-size magnetic particles and films are being used to improve computer hard-disk drives. In addition, Dr. Ijiri will discuss some of the interesting physics issues that arise is studying magnetism on such a small length scale. Specific examples will be drawn from his current work investigating iron nanoparticles, manganese nitride films, and iron oxide-cobalt oxide films. Reception to follow in Hayes Hall Lobby.


Week 3 - January 27 - 31

Friday, January 31, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.  

Friday, January 31, 3:10PM - 4PM

Physics Colloquium, Franklin Miller, Jr. Lecture Hall (RBH 109). Gerald E. Jellison, Senior Scientist, Solid State Division, Oak Ridge National Laboratory--CANCELLED
"Using Polarized Light for Materials Characterization: Transmission Ellipsometry." Abstract: Many optical characterization techniques rely on the measurement of the light intensity either reflected from or transmitted through a sample. However, there is considerably more information available, if one would also consider the changes in light polarization that the sample induces. One such example is ellipsometry, where the polarization change of a sample surface allows one to determine thin film thicknesses and refractive indices. Polarization changes from transmission measurements can be related to sample birefringence and diattenuation. The talk will consist of three parts. First, the polarization of light will be discussed using the Mueller-Stokes formalism, where it will be shown that this formalism can be used to calculate the light intensity through any polarization-dependent optical train. Second, various polarization-sensitive instruments will be examined and compared, where the connection with the Mueller-Stokes formalism will be made. Finally, the talk will focus on transmission ellipsometry using the two-modulator generalized ellipsometer (2-MGE), where the polarization characteristics of a sample can be determined either as a function of wavelength or as a x-y map. Several examples will be given, including standard laboratory materials, such as mica and Polaroid, and electro-optic materials (LiNbO3 and cadmium zinc telluride) under electric field. Reception to follow in Hayes Hall Lobby.


Week 4 - February 3 - 7

Friday, February 7, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Upper Dempsey (not the usual location, but close!) to join the department for stimulating conversation.

Friday, February 7, 3:10PM - 4PM

Physics Colloquium, Franklin Miller, Jr. Lecture Hall (RBH 109). Peter Palffy-Muhoray, Liquid Crystal Institute, Kent State University "From Artificial Muscles to Lasers: Liquid Crystals in Science and Technology"  Abstract: Liquid crystals are orientationally ordered liquids. They are anisotropic, like solid crystals, yet flow like ordinary liquids. The combination of anisotropy and fluidity gives rise to a large response to even modest stimuli, it also brings about a variety of fascinating phenomena and makes possible a wide range of applications. In this talk, I will give a brief introduction to liquid crystals, and describe some unusual phenomena occurring in liquid crystalline systems.  In addition to well known applications, such as flat panel displays, I will discuss some exciting new topics in liquid crystal research, such as mirorrless lasing in photonic bandgap materials, light-driven molecular motors, and liquid crystalline elastomers as artificial muscles. 
Reception to follow in Hayes Hall Lobby.


Week 5 - February 10 - 14

Friday, February 14, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.


Week 6 - February 17 - 21

Thursday, February 20, 7:30PM

Public Lecture, Higley Auditorium. Michael Turner, Phi Beta Kappa Visiting Scholar and the Bruce V. & Diana M. Rauner Distinguished Service Professor and Chair, Depts. of Astronomy & Astrophysics and Physics, Enrico Fermi Institute, and the College,  at the University of Chicago . "...In the Beginning." Abstract: Cosmology is in the midst of its greatest period of discovery yet. Armed with powerful ideas, colossal accelerators, large space-borne and ground-based telescopes and ultrfast supercomputers, cosmologists are trying to understand how the universe began and evolved to its present state. The history of the universe can now be traced back to a time when all we can see today was a simmering soup of quarks and other particles barely larger than the solar system. Tiday, cosmologists are striving to understand the universe when it was just quantum fuzz, and are even beginning to be able to address the question of what came before the big bang.

More about Michael Turner: Michael Turner is the Bruce V. & Diana M. Rauner Distinguished Service Professor, Depts. of Astronomy & Astrophysics and Physics, Enrico Fermi Institute, and the College, and Chairman, Department of Astronomy & Astrophysics at the University of Chicago. In addition to the many honors he has received for his research work at the forefront of cosmology, he was awarded Chicago's Quantrell Award for Excellence in Undergraduate Teaching in 1983 and was awarded the Paul Klopsteg Prize of the American Association of Physics Teachers in 1999. More information about Profesor Turner is available on his web site . He is Kenyon's Phi Beta Kappa Visiting Scholar this year.

Friday, February 21, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.

Friday, February 21, 3:10PM - 4PM

Physics Colloquium, Franklin Miller, Jr. Lecture Hall (RBH 109). Michael Turner, Phi Beta Kappa Visiting Scholar and the Bruce V. & Diana M. Rauner Distinguished Service Professor and Chair, Depts. of Astronomy & Astrophysics and Physics, Enrico Fermi Institute, and the College,  at the University of Chicago. "Dark Matter and Dark Energy in the Universe" Abstract: For the first time, we have a plausible, complete accounting of matter and energy in the universe (note, plausible does not necessarily mean correct!) According to this accounting, ordinary matter accounts for about 5% of the critical density (only about 10% of which is in the form of stars), relic elementary particles account for about 35% of the critical density, and dark energy accounts for about 60% of the critical density. The relic elementary particles are thought to be either neutralinos or axions, and their gravity holds together all structures in the universe - from galaxies to the great walls of galaxies. (A tiny fraction of the mass in all relic particles is in the form of massive neutrinos.) The dark energy, whose fundamental character is still a mystery, is causing the expansion of the universe to accelerate rather than to slow down. Reception to follow in Hayes Hall Lobby.


Week 7 - February 24 - 28

Friday, February 28, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department in celebrating the beginning of Spring Break!


Spring Break!

March 3 - 14


Week 8 - March 17 - 21

Friday, March 21, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation. We will regale each other with Spring Break adventure stories.
 

Friday, March 21, 3:10 - 3:40PM

Senior Exercise Presentation, Franklin Miller, Jr. Lecture Hall (RBH 109): Brian Long, '03, Kenyon College. Title "Apparent Shape of Large Objects at Relativistic Speeds."

Friday, March 21, 3:40 - 4:10PM

Senior Exercise Presentation, Franklin Miller, Jr. Lecture Hall (RBH 109): Jesse Gregory, '03, Kenyon College. Title "The Physics of Baseball."


Week 9 - March 24 - 28

Friday, March 28, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.

Friday, March 28, 3:10 - 3:40PM

Senior Exercise Presentation, Franklin Miller, Jr. Lecture Hall (RBH 109):  Eric Christiansen, '03, Kenyon College. Title "Problems Unique to Human Powered Flight."

Friday, March 28, 3:40 - 4:10PM

Senior Exercise Presentation, Franklin Miller, Jr. Lecture Hall (RBH 109): Gabriel Ben Meir, '03, Kenyon College. Title "Digital Reproduction of Sound."


Week 10 - March 31 - April 4

Friday, April 4, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.
 

Friday, April 4, 3:10 - 4 PM

Physics Colloquium (Franklin Miller, Jr. Lecture Hall, Hayes 109) Roger Hildebrand, The University of Chicago. "The Dust Grain and the Universe" Abstract: The smallest solid piece of the universe is a grain of interstellar dust. The biggest observable piece of the universe is "the surface of last scattering", a spherical shell 15 billion light years in radius centered on the sun. Radiation from this surface reaches us from all directions. Radiation from thin clouds of dust in our own Galaxy also reaches us from all directions. How do we tell one from the other? How do we detect either one? Why do we investigate both the dust grain and the universe? Reception will follow in the lobby of Hayes Hall.

Saturday, April 5

Physics/Math Picnic!


Week 11 - April 7 - 11

Tuesday, April 8, 11:10-11:40AM

Senior Exercise Presentation, Franklin Miller, Jr. Lecture Hall (RBH 109): Melissa Blum, '03, Kenyon College. Title "How would a Physicist Design a Tennis Racket?"

Friday, April 11, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.

Friday, April 11, 3:10PM - 4PM

Physics Colloquium, Franklin Miller, Jr. Lecture Hall (RBH 109). Robert Arns, University of Vermont "Early History of X-Ray Tubes" Abstract: 
X-rays were discovered in 1895 as byproducts of an electrical discharge in an ionized gas and for many years the gas tube was the standard means of x-ray production. These early x-ray tubes, being dependent on maintaining a narrow range of gas pressure, were capricious and unstable in operation. A 1912 paper by the Leipzig physicist Julius Edgar Lilienfeld described an x-ray tube that avoided these difficulties. It operated at a much higher vacuum and the electrons that produced the X-rays resulted from thermionic emission from a heated cathode. Lilienfeld applied for German and U.S. patents on his x-ray tube in October 1911 and in 1912. An entry in his laboratory notebook shows that William David Coolidge of General Electric Company began thinking about a high-vacuum x-ray tube with a thermionic cathode in December 1912; he applied for a patent in May 1913. The transition taking place at this time between the description of physical phenomena in terms of macroscopic variables (e.g., voltage, current, "rays," gas pressure) and the description in terms of submicroscopic events (e.g., involving atoms, ions, electrons) is vividly illustrated by the ways in which these two physicists thought about and described their x-ray tubes. This report will discuss the physics of these early x-ray tubes and the various other factors that led to Coolidge being widely acclaimed as the inventor of the "modern" x-ray tube. Reception to follow in Hayes Hall Lobby.

Week 12 - April 14 - 18

Tuesday, April 15

Honors Day!

Friday, April 18, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.

Friday, April 18, 3:10PM - 4PM

Physics Colloquium, Franklin Miller, Jr. Lecture Hall (RBH 109). Brad R. Trees, Chair, Department of Physics, Ohio Wesleyan University "Synchronized Tunneling: The Curious Dynamics of Josephson Junction Arrays." Abstract: A Josephson junction is a micron-sized weak link between two superconducting electrodes which has a nonlinear, i.e. nonohmic, relationship between the current through the link and the potential difference across it.  This nonlinear relationship results in much intriguing behavior, including the emission of microwaves when a junction is biased with a DC voltage.   Useful power outputs, however, require an array of synchronized junctions, with stable, identical voltage outputs.  In this talk we will discuss the numerical solutions to the model equations for a ladder array of junctions, looking specifically at the stability of synchronized states.  We will also discuss the relationship between the ladder array of junctions and the Kuramoto model, a famous model that describes the synchronization of coupled nonlinear oscillators. Reception to follow in Hayes Hall Lobby.


Week 13 - April 21- 25

Friday, April 25, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.

Friday, April 25, 3:10PM - 4PM

Physics Colloquium, Franklin Miller, Jr. Lecture Hall (RBH 109). Nia Imara, '03, Kenyon College "Senior Honors Talk" Reception to follow in Hayes Hall Lobby.


Week 14 - April 28 - May 2

Friday, May 2

Last day of classes for Spring Semester!

Friday, May 2, 12PM - 1PM

Physics Lunch. Bring your lunch tray to Dempsey Lounge (the room behind the partition at the south end of Lower Dempsey Dining Room) to join the department for stimulating conversation.

Friday, May 2, 3:10-4:00PM

Physics Colloquium, Franklin Miller, Jr. Lecture Hall (RBH 109). Thomas B. Greenslade, Jr., Kenyon College "The Art of Physics Demonstrations II." Reception to follow in Hayes Hall Lobby.


   
Contact:
 Jennifer Hedden , Dept. of Physics. Updated 04/05/2003