Oklahoma State Physics Department

Seminars and Colloquia, January through June, 1998

Note: This information is incomplete as not all information has been forwarded for inclusion in this page.

• This Week's schedule.
• Earlier Semesters.
• Typical Week's schedule.
• January 5-9, 1998's schedule.
• January 12-16, 1998's schedule.
• January 19-23, 1998's schedule.
• January 26-30, 1998's schedule.
• February 2-6, 1998's schedule.
• February 9-13, 1998's schedule.
• February 16-20, 1998's schedule.
• February 23-27, 1998's schedule.
• March 2-6, 1998's schedule.
• March 9-13, 1998's schedule.
• March 16-20, 1998's schedule.
• March 23-27, 1998's schedule.
• March 30-April 3, 1998's schedule.
• April 6-10, 1998's schedule.
• April 13-17, 1998's schedule.
• April 20-24, 1998's schedule.
• April 27-May 1, 1998's schedule.
• May 4-8, 1998's schedule.

Seminars and Colloquia, Typical Week:

Laser and Photonics Research Seminar:

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Oklahoma State Physics Department

Seminars and Colloquia, January 5-9, 1998

No Seminars: Preliminary Exams

Oklahoma State Physics Department

Seminars and Colloquia, January 12-16, 1998

Oklahoma State Physics Department

Seminars and Colloquia, January 19-23, 1998

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Note:

Please note new time.

Physics Colloquium:

Abstract:

The electroweak theory plus QCD works so well that it has been named the Standard Model. Nevertheless, its failure and its successor are expected to be unveiled in the next round of accelerator commissioning. We discuss how the Standard Model is tested with present accelerators, and what theory will replace it in the near future.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, January 26-30, 1998

Physics Colloquium:

Abstract:

The twistor construction of solutions of Maxwell's equations and other massless field equations will be given. The symmetries of these solutions under the group SU(2,2) are illustrated. Generalizations of this method to constructions of unitary representations of the Lie groups SU(p,q) will be explained.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, February 2-6, 1998

Center for Laser and Photonics Research Seminar:

Abstract:

Femtosecond spectroscopy opens a way toward investigation of the interactions of light and matter occurring at a time scale shorter than the period of a lattice or collective charge carrier oscillation. Coherent plasmon and phonon oscillationscan be launched by impulsive optical excitation of charge carriers in semiconductors. By using pump-probe techniques these oscillations are monitored phase-sensitively in the time domain. In compound semiconductors, the THz-electric-field oscillations associated with coherent plasmons and phonons enable the study of the dynamical electro-optic process on an ultrashort time scale. In this talk, I will present the femtosecond-optical study of THz-plasmon-phonon oscillations in GaAs and CdTe.

Note:

Refreshments served at 3:15.

Physics Colloquium:

Abstract:

I will present the simple theory of electromagnetically induced transparency (EIT) in ideal three-level atomic systems and our experimental demonstrations of this EIT effect in three-level lambda-type and ladder type systems. Applications of this EIT effect in lasing without inversion and in enhancing efficiency of nonlinear optical processes (such as four-wave mixing) will be discussed.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Center for Laser and Photonics Research Seminar:

Abstract:

I will describe an experimental demonstration of enhancing the efficiency of nondegenerate four-wave mixing (NDFWM) based on electromagnetically induced transparency (EIT) in a lambda-type three-level system of rubidium atoms. Due to EIT effect, the linear absorption term is greatly reduced, while the nonlinear generation term chi⁽³⁾ is resonantly enhanced, permitting us to observe a significant enhancement of the NDFWM signal in an optically dense medium. If time allows, I will also describe our recent experiment on coherent transient measurements in rubidium atoms by diode-laser frequency switching.

Oklahoma State Physics Department

Seminars and Colloquia, February 9-13, 1998

Physics Colloquium:

Abstract:

The history of wave optics and its influence on the emerging electromagnetic theory is a fascinating study of the early nineteenth century. Although it is commonly held that Maxwell first discovered the correct classical description of light, this is not the truth. More than 20 years before Maxwell, the equations of light were deduced using a Lagrangian variational method and symmetry principles by a physicist now almost entirely forgotten. What happened to the first gauge theory, how its author fared, and its influence on the later development of physics makes an intriguing story in the history of ideas. Reflection on the underlying fundamentals also reveals certain biases and misconceptions in modern teaching of physics.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, February 16-20, 1998

Physics Undergraduate Journal Club:

"The Discovery of the Top Quark" by Tony M. Liss and Paul L. Tipton. "Quarks by Computer" by Donald H. Weingarten.

Finding the sixth quark involved the world's most energetic collisions and a cast of thousands. Yearlong computations have helped to confirm the fundamental theory behind quarks -- and, using its principles, even to identify a new particle.

Reading Materials may be picked up in the Help Session rooms PS 249 and PS 354.

Physics Colloquium:

Abstract:

Professor Thomas Palberg, who heads a large group of students and scientists at Johannes Gutenberg University, will speak about some of his refent work with colloidal suspensions which includes: growth kinetics of body centered cubic colloidal crystals, multiphase coexistence and non-linear rheology of colloidal suspensions in an optical model capillary viscometer, probing slow fluctuations in nonergodic systems, microscopic mechanisms of nonlinear rheology of crystalline colloidal suspensions, probing dynamics of dense suspensions with 3D cross correlation techniques, buckling instability in quasi 2D colloidal suspensions, and colloidal crystallization dynamics.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, February 23-27, 1998

Physics Colloquium:

Abstract:

The neutrino was postulated by Pauli in the 1930s to ensure energy conservation in beta decay. Though a lot of effort went into neutrino experiments, much about it remained unknown. How many kinds of neutrinos are there? Are neutrinos massless particles? We are only beginning to answer these basic questions now. Recent experiments on solar and atmospheric neutrinos seem to poind towards a curious phenomenon: 'neutrino oscillations' -- a simple quantum mechanical manifestation of a non-zero neutrino mass. These and related ideas will be the main theme of this talk.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, March 2-6, 1998

Physics Undergraduate Journal Club:

The causes of color are diverse, but they all stem from the same root: It is the electrons in matter, through their varied responses to different wavelengths of light, that make the world a many-colored place.

Reading Materials may be picked up in the Help Session rooms PS 249 and PS 354.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Note:

Please note new location and time.

Physics Colloquium:

Abstract:

This talk will discuss how observations of distant comets are being used to infer conditions during the earliest era of our Solar System. The combination of new technology and large telescopes is enabling the observation and characterization of some of the solar system's smallest denizens. These observations are being combined with observations of extrasolar disks, detailed models of the early solar system and low temperature studies of laboratory ices to build up a consistent picture of the early era of our Solar System's history. Techniques for pushing comet observations to mag 30 to constrain activity, color and composition in the small body populations in the outer solar system will be discussed. A comparison of the fundamental information we can gain from observations of bright comets (using C/1995 O1 Hale-Bopp as an example) will be made with the observations of the distant comets, and unusual objects of intermediate distance.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, March 9-13, 1998

Spring Break

Oklahoma State Physics Department

Seminars and Colloquia, March 16-20, 1998

Physics Undergraduate Journal Club:

Many solid-state materials can be made to lase, but only a few have proven to be commercially successful. Many years of effort were needed to develop blue light-emitting diodes and lasers, but devices based on indium gallium nitride are now set to revolutionize optoelectronics. The road to the realization of short-wavelength, wide-bandgap, II-VI semiconductor diode lasers was fraught with scientific challenges.

Reading Materials may be picked up in the Help Session rooms PS 249 and PS 354.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Oklahoma State Physics Department

Seminars and Colloquia, March 23-27, 1998

Center for Laser and Photonics Research Seminar:

Abstract:

Image diffusion encompasses a broad class of adaptive image processing techniques based on partial differential equations. The image diffusion techniques are applicable to the image enhancement, feature extraction, scale-space generation, image segmentation and image restoration problems.

This talk explores the benefits and shortcomings of current anisotropic diffusion solutions and introduces recent innovations in the diffusion area. Specific advances in the theory include robust morphological diffusion coefficients, a diffusion technique that converges to locally monotonic root signals, extensions to multispectral imagery, multi-resolution (pyramidal) approaches, multigrid solutions and optimization techniques for ill-posed (nonconvex) image restoration problems. Applications to remote sensing, to video tracking and to automated inspection are presented. Other applications in the biomedical and telecommunications areas are discussed.

Note:

Coffee & cookies will be served prior to the seminar.

Oklahoma State Physics Department

Seminars and Colloquia, March 30-April 3, 1998

Physics Colloquium:

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, April 6-10, 1998

Special Physics Colloquium:

Abstract:

The growing popularity and availability of the Internet to the general public has launched a seemingly infinite number of on-line "resources." It has been my goal to assess some of the more valuable web pages related to physics education and to index them on a single web page to be hosted by the OSU Physics Department's web page.

The Physics Education Resource Site is separated into two main categories: the student's main page and the educator's main page. Each of these pages are broken down into several sub categories (from "Science Forums" to "Pseudo-sciences"). The contents of these categories will be discussed and selected examples will be presented as they appear on the Internet.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:00 p.m. All students are welcome! Refreshments will be served.

Note different time and location.

Public Lecture by the Co-Recipient of the 1997 Nobel Prize in Physics:

Abstract:

Atomic clocks are the most accurate timepieces ever made, and are essential for such features of modern life as synchronization of high speed communication and the operation of the Global Positioning System that guides aircraft, boats and backcountry hikers to their destinations. The limitations of atomic clocks come from the thermal motion of the atoms: hot atoms move fast and suffer from time shifts as predicted by Einstein's Theory of Relativity.

Contrary to intuition, we can cool things by shining laser light on them. With laser cooling, we cool gases to less than one millionth of a degree above Absolute Zero. The slowly moving atoms in ruch a gas allow us to make even more accurate clocks, perhaps so good that they would lose or gain only a few billionths of a second a year. Laser cooling has also made possible the recent observation of a long-standing prediction of Einstein: Bose-Einstein condensation, hailed a one of the most important scientific developments in recent years.

This talk will be accessible to those whose last formal science education was in high school, but will discuss some of the most recent and exciting developments in physics.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Physics Undergraduate Journal Club:

The announcement of evidence for relic life in a Martian meteorite was met by universal skepticism by the scientific community in the summer of 1996. However, before the community could formally respond, the attention given the discovery by the media, the administrator for NASA and the President of the U.S., meant that NASA and NSF established funding programs to support this area of research and the establishment of a new Center for Astrobiology at the Ames Research Center in California. This episode provides an interesting comparison to the supposed discovery of cold fusion a few years ago, and provides many insights into the way Science, Politics and Human Affairs interact.

Reading:

1. "The case for relic life on Mars," E.K. Gibson, D.S. McKay, K. Thomas-Keprta and C.S. Romanek, Scientific American, December 1997, page 36.
2. "Lack of life?," R. Kerr, Science, January 16, 1998, page 279.

Reading Materials may be picked up in the Help Session rooms PS 249 and PS 354.

Physics Colloquium:

Abstract:

The interference patterns created by intersecting laser beams produces a periodic variation of intensity and polarization that can both cool atoms and trap them at regularly spaced lattice positions. Such optical lattices have many features in common with solid crystals, but with lattice spacings a thousand times larger. The quantum motion of the atoms in these optical lattice potentials can be studied by spectroscopy, Bragg scattering, and coherent redistribution of radiation.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:00 p.m. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, April 13-17, 1998

Special Physics Colloquium:

Abstract:

String phenomenology is the interplay between the Planck-scale physics of string theory and the observable "low-energy" phenomena of modern particle physics. As such, it provides the means by which the ideas of string theory can have an impact at presently accessible energy scales. In this talk, I will provide a non-technical survey of the basic ideas of string theory, and I will highlight the role that string phenomenology plays in guiding present and future theoretical developments. I will also give examples of how string phenomenology suggests new and unconventional approaches for tackling some presently unsolved puzzles.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Please note that this talk is on a Monday.

Special High Energy Talk-Back TV Seminar:

Note:

Please note that this talk is on a Tuesday.

Special High Energy Talk-Back TV Seminar:

Note:

Please note location and time.

Physics Colloquium:

Abstract:

The Orion Nebula is not only the dominant object in the early evening sky, but also the closest region of formation of massive stars. Such clusters are thought to be the prototypes of star formation in general. This talk will report on the results of using the Hubble Space Telescope to explore the Orion Nebula. This study has discovered that circumstellar disks seem to be the rule, rather than the exception. Although such disks were inferred to exist near other young stars, this is the first direct detection. Since such disks are the building blocks necessary for planet formation, these observations argue that planets may be the rule rather than the exception.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Special Physics Colloquium:

Abstract:

Supersymmetry is a proposed extension of the Standard Model of high energy physics which predicts a plethora of new fundamental particles. If supersymmetry is correct, then many or all of these particles should be discovered within the next decade. Most of the outstanding questions about supersymmetry, both theoretical and phenomenological, revolve about the central issue of how it is spontaneously broken. In this talk, I will describe the motivations for supersymmetry, compare the two leading candidate ideas for describing supersymmetry breaking, and contrast their experimental consequences.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Please note that this talk is on a Friday.

Oklahoma State Physics Department

Seminars and Colloquia, April 20-24, 1998

Special Physics Colloquium:

Abstract:

The concept of grand unification, in which the strong, the weak and the electromagnetic interactions are unified into one, will be introduced. After describing its triumphs in explaining various observed phenomena, I will discuss the challenges that are faced by any realistic grand unified model. A new approach that overcomes these challenges will be presented. It has important ramifications for several fundamental problems such as fermion mass generation, neutrino oscillations and proton decay. I will conclude by outlining tests of this idea at ongoing and forthcoming experiments.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Please note that this talk is on a Monday.

Special High Energy Talk-Back TV Seminar:

Note:

Please note that this talk is on a Tuesday.

Physics Colloquium:

Abstract:

There is excitement in structural biology today that echoes what geographers must have felt in the time of Magellan. New coastlines, in the form of novel protein structures from NMR and X-ray crystallography, appear almost weekly in the leading journals. Although to date we have seen perhaps only 10% of the 'globe' of all protein structural types, motifs have emerged that suggest the structures of a comparatively small number (~5000) of carefully-selected proteins might be used to predict the structures of the remainder to moderate (2.5A) resolution. A large-scale project along these lines is being organized right now. We discuss how physics and physicists can contribute to this effort. We end with a trip up one tributary, the family of heme proteins, to take a look at how a simple protein, myoglobin, works.

Note:

The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:30 p.m. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, April 27-May 1, 1998

Prefinals Week

Oklahoma State Physics Department

Seminars and Colloquia, May 4-8, 1998

Finals Week

OSU Biophysics Journal Club:

Abstract:

Dramatic advances in biochemistry have explained many aspects of the functioning of living organisms in terms of the remarkable properties of proteins. The next step is to understand the functioning of proteins in physical terms. Two major questions are: How do proteins spontaneously fold into highly specific structures upon their synthesis? And how do proteins perform their functions? In this talk these questions will be approached using photoreceptor proteins. In addition to being of importance in their own right as biological light sensors, these proteins provide unique opportunities to examine the basic principles of protein function and folding.

Note:

After the talk, let us decide whether we should continue through the summer, and, who will be the next speaker.

Last Updated: 14 April, 1998.

This page was prepared by Helen Au-Yang and Jacques H.H. Perk.