Wednesday, April 21, BT 251/2, 4:35 to 5:25 pm

What Works for Women in Undergraduate Physics

Barbara L. Whitten
Physics Department and Women's Studies Program, Colorado College

The participation of women in physics has increased in recent years, but the percentage of women in physics is still less than half that in mathematics and chemistry. This is due in large part to the "leaky pipeline" -- the participation of women in physics decreases with every step up the academic ladder. The largest decrease occurs between high school and college graduation, so it is worthwhile looking at how undergraduate physics departments try to make women undergraduates comfortable. With a team of women physicists, I visited nine undergraduate physics departments and compared those that are successful in producing a large percentage of women with those that are more typical of the national average. We found that the most important factor is a warm and female-friendly department culture that reaches out to introductory students. I'll discuss the factors that make up a female-friendly culture, and describe other results of our research.

Funding provided by the NSF Program for Gender Equity.

Wednesday, April 21, SUB Activities Room, 7:30 to 8:30 pm

You Can Always Find Women in Science, If You Look

Barbara L. Whitten
Physics Department and Women's Studies Program, Colorado College

In 1986 Sandra Harding, the well-known philosopher of science, wrote that "few women have been able to achieve eminence in their own day as scientists." She has probably repented that statement, since historians of science have discovered women scientists in every field, every country, and every time period. No matter how high the barriers, women have always found ways to participate in science. In this talk, I will discuss why women's achievements have been so invisible. I will assess the present situation, and offer hope for the future.

Wednesday, March 31, MG 2050, 4:30 to 5:20 pm

Women and Engineering: A Historical Perspective

Amy Sue Bix
Department of History, History of Technology and Science program, Iowa State University

Recently, there has been much interest in ways to encourage more women to enter science and engineering and to support their work in these fields. Amidst such discussions, it proves useful to understand the historical background of how women first entered science and engineering. This extensively-illustrated talk explores twentieth-century changes in the educational and professional climate of engineering, which (even more than science) had been traditionally considered a masculine domain. Up through WWII and beyond, some of the nation's foremost engineering schools discouraged or refused to accept female students. Gradually, Georgia Tech, Caltech, and RPI moved toward coeducation, each for different reasons, and amidst heated debate by students, faculty, alumni, and administrators. During the 1960s and 1970s, supporters of women in science pressed MIT to improve its notoriously hostile conditions for female students. Yet as recent studies have shown, many concerns remain about women's place in modern engineering.

Wednesday, March 24, BT 251/2, 4:35 to 5:25 pm

Student Summer Research Presentations II

Sarah Smith: "Fluorescent Time Lapse Microscopy of Early Embryo Development of S. Purpuratus."

Justin M. McAninch: "Correlation Study: Ionospheric Disturbances and Sunspot Activity." Work done here at Truman State University.

Amenyedu D. Adovor: Astronomy Of Asteriods.

Wednesday, March 3, BT 251/2, 4:35 to 5:25 pm

Vector Calculus for Lattice Models with an Application to Polaron Dynamics

Brian Moritz
University of North Dakota - Morris

Recently, we developed a formalism of a discrete vector calculus for use with lattice models of physical systems. The formalism includes discrete analogs of the familiar differential vector calculus operations such as the gradient, divergence, curl, scalar multiplication, the scalar or dot product, and the vector or cross product. In addition, there exist discrete analogs of Gauss's Law, Stokes' Theorem and the fundamental theorem of calculus. The discrete theory borrows heavily from the theory of differential forms as well as homology and cohomology theory from algebraic topology.

As an example, the discrete vector calculus will be applied to a model that shows interesting polaron-like behavior. The model consists of an electron coupled to a classical polarization (distortion or strain) field. The model exhibits both mass enhancement and lifetime broadening effects indicative of the formation of a polaron. In addition, it is seen that the electron "self-traps" for a sufficiently large coupling constant.

Monday, March 1, BT 251/2, 4:35 to 5:25 pm

Edge Magnetoplasmon Modes in a Partially Screened Two-dimensional Electron Gas

Mehmet Ilhan Göksu
Case Western Reserve University

Two dimensional (2D) electron systems on the liquid helium surface have been of great interest in experimental and theoretical studies during the last three decades. The observation of an edge magnetoplasmon (EMP) mode is one of the intriguing phenomena in the 2D electron system. EMP modes are magnetoplasmon modes in a magnetic field applied normal to 2D plane, and they propagate along the perimeter of a sample. The characteristic property of the EMP mode is that its frequency decreases with increasing magnetic field applied perpendicular to the electron array. A series of experiments were performed in which EMP modes of a partially screened two-dimensional electron fluid on the surface of liquid helium confined to a circular area were analyzed. In this talk, I will present a study of partially screened EMP modes to test theoretical predictions.

Wednesday, November 19, BT251/2, 4:35 to 5:25 pm

Student Summer Research Presentations I

Karl Franz Flasch Hendrickson: "Superconductivity and the Cosmic Microwave Background." Work done at the University of Wisconsin-Madison.

Kibrom Tewolde: "Interface Resistance in Au/Pd and Ag/Pd inserts in GMR multilayers." Research conducted at Michigan State University, Physics and Astronomy Division.

Suzanne Leslie: "Laser Cooling and Bose-Einstein Condensation." Product of a Research Experience for Undergraduates at Oklahoma State University in Stillwater.

Wednesday, October 29, BT 251/2, 4:35 to 5:25 pm

Did a Gamma-Ray Burst Initiate the Late Ordovician Mass Extinction?

Adrian L. Melott
Department of Physics and Astronomy, University of Kansas

A GRB within our galaxy could have catastrophic consequences for the Earth. Extrapolations from the global rate suggest an average interval of 0.1 to 1 Gy for events in which the Earth is irradiated from a distance of a few kpc. Prompt emission would irradiate the surface with UV about one order of magnitude more intense than the present solar IR/visible/UV flux. The atmosphere would become heavily ionized, resulting in major destruction of the ozone layer. If high energy cosmic rays accompany the GRB, the surface is bathed in secondaries including highly energetic muons.

Both the prompt UV and that resulting from long-term loss of the ozone layer are destructive to living organisms. The attenuation length of UV in water is tens of meters. There is a strong candidate for a GRB based mass extinction in the late Ordovician, 440 My ago. Planktonic organisms and those animals living in shallow water seem to have been particularly hard hit during this mass extinction.

For more information, see articles in New Scientist and Nature.

Thursday, October 16, BT251/2, 4:35 to 5:25 pm

Spintronic Materials: Growth, Characterization, Physics, and Devices

Kartik Ghosh
Physics, Astronomy and Materials Science Department, Southwest Missouri State University

Recently, a new field has emerged, called spintronics or sometimes magnetoelectronics, which combine both the spin and charge of electrons to obtain devices with new functionality and increased performance. The advantages of these new devices would be nonvolatility, increased data processing speed, decreased electric power consumption, and increased transistor density compared with conventional semiconductor devices. However, the success of the field of spintronics depends on materials with large spin polarization. Currently, it has been found that dilute magnetic semiconductors (DMS) have 100% spin polarization. DMS (also called spintronic materials) are new classes of ferromagnetic semiconductors formed by incorporating small percentages of transition metals (such as iron or cobalt) into normal semiconductors (such as GaAs, TiO₂ or ZnO). The growth of high quality thin films of DMS materials and their property characterization are very important in the materials science research. This presentation will discuss our recent research activities such as growth of high quality thin films, structural characterization, and magneto-transport and optical properties studies of spintronic materials (e. g. GaAs-based and TiO₂-based dilute magnetic semiconductors). A better understanding of the DMS will lead us to make spin transistors and high density nonvolatile magnetic random access memories those can be used in many electronic devices such as computers, digital cameras, and cell phones.

Wednesday, October 1, BT251/2, 4:35 to 5:25 pm

Advanced Lab Presentations on Current Issues in Experimental Physics

Karl Hendrickson: "First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Preliminary Maps and Basic Results"
An introduction to the Cosmic Microwave Background and its observation. Maps from the first year of data from the Wilkinson Microwave Anisotropy Probe (WMAP) are presented and discussed with respect to their cosmological implications.

Jarrett Johnson: "LIGO: The Strategy and First Results in the Search for Gravitational Waves"
General Relativity predicts the existence of gravitational waves and, while indirect experimental evidence for them has been found, their direct observation remains a major goal. The Laser Interferometer Gravitational-Wave Observatory is a project aiming to detect gravitational waves emitted by merging neutron stars and black holes. The first data in this search are presented and the essentials of the strategy behind the project are outlined.

Suzanne Leslie: "Production and Detection of Antihydrogen at CERN"
Two research groups at CERN (ATHENA and ATRAP) have been aspiring to make precision tests on antihydrogen to investigate how an atom of antimatter may differ from its ordinary-matter counterpart. I will talk about the methods in which the antihydrogen is being formed and detected, as well as briefly discuss the future plans of these groups.

Thursday, April 17, BT251/2, 4:35 to 5:25 pm

Small Radio Telescope

Michael Cobb
Department of Physics, Southeast Missouri State University

The Small Radio Telescope (SRT) was developed by Haystack Observatory at MIT as part of their educational outreach program. The SRT uses commercial C Band dishes and feeds combined with a FFT based digital receiver designed by Haystack Observatory with a fully controllable 2 axes mount. The SRT was designed as an educational tool to observe in the HI (21 cm) spin flip line as well as thermal emission from the Sun and star formation regions. Haystack Observatory has developed a series of exercises designed to teach radio astronomy fundamentals to advanced high school and undergraduate students. This talk will review the development of the SRT its capabilities and future design goals including GPS timing modules which will allow Very Long Baseline Interferometry (VLBI) techniques to be used to record data at various telescopes and combine them to form high resolution images.

Saturday, April 12, VH 1000, 9:45 to 10:45 am

Prospects for Atom Interferometry

Gilford S. Summy
Oklahoma State University

Atom interferometers were first realized a little more than ten years ago, and since then have evolved from beautiful demonstrations of quantum physics into instruments at the leading edge of precision measurement. In this talk I will trace the development of atom interferometry, looking at how the physical principles have been put into practice to achieve ground breaking experiments. I will also discuss how advances in atom optics are leading to improvements in matter wave interferometry that will provide new opportunities for metrology and the study of fundamental physics.

Wednesday, December 4, BT 251/2, 4:35 to 5:25 pm

Student Summer Research Presentations (III)

Jessica Rolwes, Michelle Hannon, Lucas Ward
Truman State University, Science/Physics

Three 15-minute talks by Truman physics students on the work they did during their summer research experiences. Jessica Rolwes will talk about the detection of TNT using micro electrical mechanical systems (MEMS), based on her research at Oak Ridge National Laboratory. Michelle Hannon will present on "Simulating Quantum Photon Communication Through Free Space." Lucas Ward's topic is "XPS and UPS photoelectron spectra of cyanogen chloride deposited on silicon (100)."

Wednesday, November 20, BT 251/2, 4:35 to 5:25 pm

Glass Research at the University of Missouri-Rolla

Richard K. Brow
Ceramic Engineering Department, University of Missouri-Rolla

Glass compositions can be tailored to optimize physical properties for a variety of optical, medical, and environmental applications and it is desirable to develop an understanding for those properties depend on the molecular-level structures of these materials. For example, the physical properties of simple rare earth phosphate glasses, used as models for more complicated laser glass compositions, are sensitive to changes in the coordination environment of rare earth ions. The strength of glass fibers depends on molecular-structure, as well as the conditions under which the glass is fabricated. Pristine glass fibers are stronger than steel, but are rapidly degraded by handling and by exposure to atmospheric water. Other examples that will be discussed include glasses that convert to biologically compatible materials and glasses developed to encapsulate radioactive wastes.

Wednesday, November 13, BT 251/2, 4:35 to 5:25 pm

Of Gods, Dice, and Spooky Actions At a Distance: Introduction to Bell's Inequality

David Branning
Department of Physics, University of Illinois at Urbana-Champaign

Quantum mechanics does not make deterministic predictions about the outcomes of single measurements in all cases: when many outcomes are possible, the result is a random selection from among them. But is this randomness an intrinsic characteristic of nature, or does it arise merely from our ignorance about what is "really going on" in quantum systems? The question of whether or not quantum mechanics is a complete description of nature was first raised by Einstein, Podolsky, and Rosen in 1935. The debate was a philosophical one until 1964, when John Bell gave us the first in a series of formal inequalities that let us test, experimentally, whether it would be possible to construct more complete "local-realistic" theories to replace quantum mechanics. I will discuss the Einstein Podolsky-Rosen paradox, the Bell Inequalities, and several of the landmark experiments that have been performed in the past 30 years to test them.

Friday, November 8, BT 251/2, 10:35 to 11:25 am

Quantum Hall Liquid Crystals

Carlos Wexler
University of Missouri-Columbia

Recently discovered extreme anisotropies of the magnetotransport in two dimensional electron systems (in the intermediate regions between quantum Hall plateaus) has been attributed to the formation of a liquid crystalline phase at temperatures below ca. 100 mK. In this talk I will present a first principles calculation of the energetics of a system of interacting electrons in a partially filled Landau level, leading to an equivalent model which behaves like a smectic (positional and orientational order, e.g. "stripes") or a nematic (orientational order only) depending on the temperature. We find a qualitatively correct prediction of the anisotropic-isotropic transition via the Kosterlitz-Thouless disclination unbinding mechanism. If time permits, I will also present an alternative microscopic derivation of a quantum Hall nematic state.

Wednesday, October 30, BT 251/2, 4:35 to 5:25 pm

Student Summer Research Presentations (II)

Suzanne Leslie, Heather Molle, Michael Cone
Truman State University, Science/Physics

Three 15-minute talks by Truman physics students on the work they did during their summer research experiences. Suzanne Leslie's research was on "the Effects of Proton Bombardment on the Electrical Properties of Polymers," conducted at the Indiana University Cyclotron Facility. Heather Molle will speak on "Using Wavelets to Solve Time-Dependent Quantum Equations," based on work done at Rice Quantum Institute, Rice University. Michael Cone's topic is "Computer Modeling of the Dynamics of Charged Dust Particles in Saturn's F-ring"; he did this research at Baylor University.

Wednesday, October 23, BT 251/2, 4:35 to 5:25 pm

Student Summer Research Presentations (I)

Kevin Haworth, Sarah Smith, Todd Lansford
Truman State University, Science/Physics

Three 15-minute talks by Truman physics students on the work they did during their summer research experiences. Kevin Haworth will present "Improving Diagnostic Measures for the Synchrotron Ultraviolet Radiation Facility"; this work was done at NIST, within the Electronic and Optical Physics Division of the Physics Laboratory. Sarah Smith will talk about "Optical Microfluidics" and her work at SRI International. Todd Lansford will speak on "Three-dimensional Analysis of BaTiO₃ Thin Films," done at Northwestern University.

The Formation Of Elliptical Galaxies

Keith Ashman
University of Missouri Kansas City, Department of Physics and Astronomy

One of the great challenges of extragalactic astronomy is understanding why massive galaxies come in two distinct morphological types. Spiral galaxies are flattened, rapidly rotating disks of stars and gas. When viewed face on, these objects exhibit "spiral arms" of young stars, giving them the appearance of a pinwheel. Elliptical galaxies are much rounder than spirals and rotate slowly, if at all. They contain little gas and few if any young stars. I will describe how these differences between spiral and elliptical galaxies might arise.

Advanced Lab Presentations on Current Issues in Experimental Physics

Derrick Rohr, Lucas Ward
Truman State University, Science/Physics

Students in Advanced Lab II are required to make formal presentations based on an article about some current work in experimental physics. Derrick Rohr will be presenting on "Super Kamiokande et.al.": three labs and their methods of neutrino collection. Lucas Ward will talk about alternative methods being investigated for cooling and trapping molecules, as laser cooling, which works with atoms, is not a viable option for molecules.