RESEARCH NEWS
LOVE NAMED ASSOCIATE EDITOR AT PHYSICAL REVIEW C
7/02 Regents' Professor W. Gary Love has been appointed as an Associate Editor of Physical Review C. The journals Physical Review A-E, published by the American Physical Society, are the prime U. S. physics journals and arguably the world's most respected physics journals. Physical Review C publishes current research in experimental and theoretical nuclear physics.
DENNIS ELECTED DIRECTOR OF NanoSEC
9/02 Professor William M. Dennis has been elected the director of the University of Georgia Nanoscale Science and Engineering Center (NanoSEC). The Center brings together a truly multidisciplinary team of over twenty investigators with extensive experience in experimental, theoretical and computational techniques from the biological and physical sciences and engineering.
HAUSCHILDT AND SCHWEITZER ILLUMINATE BROWN DWARFS
|
1/02 Warm brown dwarfs are cloud shrouded, cool brown dwarfs have clear, rained out atmospheres. This is the result of a comprehensive study presented on 1/8/02 at the meeting of the American Astronomical Society in Washington, DC by astronomers Andreas Schweitzer (Univ. of Georgia), John E. Gizis (Univ. of Delaware), Peter H. Hauschildt (Univ. of Georgia), France Allard (Centre de Recherche Astronomique de Lyon, France), I. Neill Reid (Univ. of Pennsylvania) and J. Davy Kirkpatrick (California Institute of Technology). The derived surface temperatures make the coolest brown dwarfs as warm as the warmest extrasolar giant gas planets and the warmest brown dwarfs as cool as the coolest stars. For more information, click here. |
LEWIS GIVES INVITED TALK AT INTERNATIONAL CONFERENCE IN JAPAN
|
5/01 Prof. Steven Lewis was featured as an invited speaker at the 10th International Conference on Time-Resolved Vibrational Spectroscopy, held May 21-25, 2001, in Okazaki, Japan. This interdisciplinary conference brought together scientists from four continents to discuss recent experimental and theoretical developments in time-resolved vibrational spectroscopy and applications to materials, chemical, and biological systems. Prof. Lewis presented his theoretical work on adsorbate vibrational relaxation in a talk entitled "Collective Effects and Structural Order in Low-Frequency Adsorbate Dynamics". |
HAUSCHILDT AND COLLEAGUES ANNOUNCE "RESOLUTION" OF A DISTANT STELLAR DISK USING VLT SPECTRA
|
4/01 Like our Sun, stars are large gaseous spheres. However, while we are able to perceive the Sun's disk, all other stars are so far away that they normally appear as points of light. Only specialized observing techniques, like interferometry, are able to "resolve" the images of nearby stars and to show them as extended balls of fire. But opportunities may sometimes arise that allow amazing observational feats in this field. Indeed, an international team of astronomers has just "resolved" a single, normal star some 25,000 light years away, or about 1.6 billion times more distant than the Sun, by taking advantage of a multiple microlensing event. During such a rare event, the light from the remote star is amplified by the gravity of a faint object that passes in front of it, as seen from the Earth. In fact, this gravitational lens acts as a magnifying glass that focusses different parts of the star's image at different times. Using the FORS1 multi-mode instrument at the 8.2-m VLT ANTU telescope on Paranal during a microlensing event, the team was able to obtain detailed spectra of the different parts of the remote star. In doing so, they managed to probe its gaseous atmosphere at different depths. This is the first time that it has been possible to obtain detailed, spatially resolved spectra across the full face of a normal star other than the Sun For more information go to http://www.hq.eso.org/outreach/press-rel/pr-2001/pr-09-01.html |
FUGAO WANG WINS RESEARCH AWARD
4/01 At the 22nd Annual Research Awards Banquet, Mr. Fugao Wang received the Excellence in Research by a Graduate Student Award for the Mathematical and Physical Sciences. Large scale computer simulation methods have sparked a revolution in research in physics and represent a true paradigm shift that is already spilling over into other disciplines. Working in the Center for Simulational Physics under the direction of Prof. D. P. Landau, Mr. Wang developed a novel extension of a powerful technique, called the Monte Carlo method, that generates large numbers of the states of a system using stochastic sampling methods. Problems arise, however, near phase transitions and in systems with complicated energy “landscapes” since all known methods become inefficient. Mr. Wang has pioneered a method that avoids these complications completely by instead directly determining the “density of states”. Results can then be produced for any temperature from a single simulation! The impact of Mr. Wang’s Ph.D. research is immense. The study of phase transitions is of great importance in statistical physics and his method solves two of the most computationally challenging problems in their study. Problems with rough energy landscapes appear in many areas from spin glasses to integrated circuit design, protein folding, and computational finance. In addition to a Certificate, the recipient of this award receives a check for $1000.
HAUSCHILDT AND COLLEAGUES INFER "FREE FLOATING" PLANETARY MASS OBJECTS
4/01 Dr. Philip Lucas (University of Hertfordshire) and Dr. Patrick Roche (Oxford University) controversially announced last year that they had directly observed 13 faint points of light in Orion (a giant stellar nursery where thousands of stars are being born) which appeared to have masses closer to those of the giant planets--a few times more massive than Jupiter in our Solar System--than the stars.
On Tuesday 3 April, the same pair announced at the UK National Astronomy Meeting in Cambridge that they have confirmed their discovery of 'free floating planets' in the Orion Nebula. Their measurements of the spectrum of the infrared light from 20 objects in the Nebula show the characteristic signature of water vapour. This confirms that these objects are indeed young, low-mass bodies, and that the faintest of them are of planetary mass. These planetary mass objects can only be seen because they are very young and still warm after the process of formation.
Dr Lucas commented, "It's exciting to find these planet-sized objects floating around in space, unlike planets such as our Earth which orbit a star. Our new results provide the first steps in the exploration of their physical properties."
Dr. Peter Hauschildt (UGA) and his colleague France Allard performed the atmosphere modeling that was used to constrain the temperatures and thus the mass range of these objects.
LANDAU PRESENTS LECTURES IN GERMANY
04/01 David P. Landau, Distinguished Research Professor of Physics and Director of the Center for Simulational Physics, was a featured Invited Speaker at the "Spring School on Computational Physics" sponsored by the German Physical Society in Bad Honnef, Germany. He spoke about "An Introduction to Monte Carlo simulations in Statistical Physics". The lectures were sponsored by the Hereaus Foundation and were intended to introduce young German scientists from all phases of university and industry to modern computer simulation techniques.
TEMPLON IS CO-SPOKESPERSON OF JEFFERSON LAB EXPERIMENT
02/01 Prof. Jeff Templon recently was co-spokesperson (along with
Dr. Joseph Mitchell, Jefferson Lab) of an experiment in Hall A at Jefferson Lab in Newport
News, Virginia. Prof. Templon and Dr. Mitchell had the experimental resources of Hall A,
and beam from the CEBAF electron accelerator, for the entire month of October 2000. In
order to be awarded this month of "beam time", Prof. Templon wrote and defended
a research proposal before an international advisory panel of distinguished nuclear
physicists. Scientists from universities across the US, as well as from The Netherlands,
Korea, France, Israel, and Switzerland came to take part in the experiment.
The experiment uses beams of electrons, travelling 99.999999% of the speed of light, to
probe details of the interactions between protons and neutrons inside helium nuclei.
Nuclear theorists believe that a careful measurement might reveal the details of how these
particles interact when they come very close (within 10-15 m) of each other.
Scientists understand how these particles interact when they are not so close together,
but have been unable to find a satisfactory understanding of these close encounters.
Prof. Templon and his graduate student, Jianning Zeng, are currently working on analyzing
the results of the experiment. The analysis involves heavy use of computers, since
hundreds of millions of nuclear reactions were recorded during the experiment. They use
computational resources in the Physics Department here in Athens, as well as those of a
computational "farm" at Jefferson Lab.
LANDAU PRESENTS INVITED TALKS
09/00 David P. Landau, Research Professor of Physics and Director of the Center for Simulational Physics, presented an Invited Talk at the Fourteenth Symposium on Thermophysical Properties on the campus of the University of Colorado–Boulder. This was organized by the National Institute of Standards and Technology and the Committee on Thermophysical Properties (Heat Transfer Division, American Society of Mechanical Engineers). The title of his presentation was "Monte Carlo Studies of Wetting and Interface Unbinding in the Ising Model." Participants at this large meeting came from an international collection of both university and industrial researchers, and included results of experiment, theory, and simulation.
David P. Landau, Research Professor of Physics and Director of the Center for Simulational Physics, presented an Invited Talk at the Ising Centennial Colloquium in Belo Horizonte, Brazil. This special event was held to honor the birth of Ernst Ising whose special theoretical model has become the "fruit fly" of statistical physics. (At last count there were over 16,000 literature citations to his famous paper.) Prof. Landau’s presentation was on "The Ising Model as a Playground for the Study of Wetting and Interface Phenomena," and described the results of a decade of increasing powerful simulations carried out in the Center for Simulational Physics. Much of this work was possible only because of the state-of-the-art high performance computing facilities maintained by UCNS.