APS News

Physicists Head to Florida Coast for 2005 APS April Meeting

Photo Courtesy of Tampa Bay CVB
Photo Courtesy of Tampa Bay CVB

Physicists will be heading down to the Sunshine State later this month for the 2005 APS April Meeting, to be held in Tampa, Florida, April 16-19. The scientific program will feature about 75 invited sessions and more than 100 contributed and poster sessions, on topics ranging from astrophysics, nuclear physics, particles and fields, plasma physics, and computational physics.

This meeting also serves as the 2005 divisional meeting of the Division of Particles and Fields.

Among the highlights of the technical program are a series of plenary lectures on a wide range of topics. Nobel Laureate Carl Wieman, of the University of Colorado at Boulder will talk about different perspectives demanded by research and teaching. Other speakers include Stanford University's Leonard Susskind, who will talk about the black hole information paradox, and his Stanford colleague, Patricia Burchat, who will discuss the mysteries of heavy quarks. Additional speakers will cover the use of gamma rays to probe supernova remnants, black holes and dark matter; the physics of nanoscale structures; the physics of accreting neutron stars; a new way of envisioning particles and their interactions; and probing subatomic matter with polarized electrons.

Other topics at the meeting include the physics of extra dimensions and warped fermions; various viewpoints on current visa restrictions on international exchange; recent developments in string theory, including a talk by bestselling author Brian Greene of Columbia University; extrasolar planets; communicating physics to non-physicists; and a special session of award presentations that will feature the annual Lilienfeld lecture by Robert Austin of Princeton, and the retiring presidential address, given this year by APS Past President Helen Quinn of Stanford University.

Even More Einstein. The World Year of Physics marches on in celebration of Einstein's "miracle year," and several sessions at the meeting are Einstein-centric. There will be a special public lecture by Case Western Reserve University's Lawrence Krauss, bestselling author of The Physics of Star Trek, on the mysteries surrounding Einstein's cosmological constant, which he once called his "biggest blunder." A Saturday evening session will review Einstein's scientific legacy, outlining what is currently known and unknown. On Sunday, various speakers will discuss Einstein's friendships and collaborations with such eminent figures as Michele Besso, Ernst Mach, and Satyendra Nath Bose.

Catching a Gravitational Wave. Two major scientific collaborations are well on their way to testing Einstein's predictions in general relativity by searching space for gravitational waves. Various scientists from the LIGO collaboration will present new results in the search for black holes and gravitational waves from neutron stars and radio pulsars, among other objects. On the horizon is the planned space-based Laser Interferometer Space Antenna (LISA), which will be sensitive to gravitational waves in the mHz band. Several speakers will discuss potentially powerful sources, including massive black hole binaries and globular cluster systems.

Deep Galaxies. The DEEP2 project, headquartered at UC Berkeley and UC Santa Cruz, is a large galaxy-redshift survey mapping the location of 50,000 galaxies. Unlike the Sloan Digital Sky Survey and 2dF, prominent surveys which look at relatively nearby galaxies, DEEP2 centers its attention farther out, to a time about halfway back to the Big Bang. Marc Davis will report on new findings about the clusters of galaxies at that redshift and might, depending on the progress of data analysis, be able to provide the best astrophysical test yet of the proposition that the fine structure constant has been changing down through the eons.

Quantum Loops and the Black-Hole Information Paradox. Like its rival, string theory, loop quantum gravity aims to reconcile the venerable but incompatible theories of general relativity, which describes the universe at large scales, and quantum mechanics, which describe nature at the atomic scale. Unlike string theory, which starts off by assuming space-time is smooth and continuous, loop quantum gravity assumes fundamentally that space-time at the smallest scales is discontinuous and chunky. The fabric of space-time is literally woven by quantum threads and is best described by a "quantum geometry." Abhay Ashtekar, the director of Penn State?s Institute for Gravitational Physics and Geometry, will present a detailed solution to the so-called "information-loss paradox" associated with black holes.

Mouse Thyroids Go Radioactive. In parts of the US and elsewhere potassium iodide (KI) tablets have been made available for use by humans so as to load the thyroid with stable iodine in the event of an accidental or terrorist-triggered release of radioiodine. An interdisciplinary collaboration among physicists and biologists at the College of William and Mary and the DOE's Thomas Jefferson National Accelerator Facility has been studying the effectiveness of ordinary KI in blocking the absorption of radioactive iodine in the thyroid of a mouse. The research has shown that the human-recommended KI blocking dose, when scaled to a mouse, mostly blocks uptake of radioactive iodine.

Search for ExaVolt Neutrinos. Neutrinos made inside the sun from nuclear fusion reactions typically have energies of mega-electron volts (MeV). But theorists expect that other, more powerful processes might endow 's with energies of 1018 eV or more. The Antarctic Impulsive Transient Antenna (ANITA) is designed to detect exactly this sort of particle. ANITA consists of an array of antennas mounted on a balloon flown above the Antarctic icecap. Peter Gorham will present the first ANITA results.

Do We Really Understand Gravity? Some physicists wonder whether the evidence in favor of dark matter and dark energy isn't pointing to a breakdown in an understanding of gravity. The answer is probably "no," but physicists are speculating on alternatives. Hiranya Peiris of the University of Chicago will cover some of the best cosmological observations, especially of the microwave background, and how they can be used to constrain novel theories of gravity. Arthur Kosowsky of Rutgers will discuss dark matter and possible alternatives. And Mark Trodden of Syracuse University will take a similar tack towards the acceleration of the universe, which is usually taken to indicate the presence of dark energy.

Is the Pentaquark an Endangered Species? For decades, physicists had only seen evidence that quarks clump in groups of two and three. In the last three years, however, experiments produced evidence for exotic four- quark (tetraquark) and five-quark (pentaquark) states. On the heels of a dozen "positive" sightings of the pentaquark, there has been a flurry of negative ("null") results, most containing better statistics, from experiments including CDF at Fermilab, BaBar at SLAC, and collaborations at CERN in Switzerland and DESY in Germany. Curtis Meyer of Carnegie Mellon will review the current evidence for and against the pentaquark.

Plasma Acceleration. Accelerating charged particles to high energies is usually achieved by boosting the particles in powerful electromagnetic fields supplied by microwave devices. An alternative method, with a potentially much higher acceleration gradient, is to use waves moving through a column of plasma to boost electrons to high energies. Chandra Joshi of UCLA, working at the SLAC machine at Stanford, will report on the present ability to impart energy gains of 4 GeV over only a 10-cm length of plasma and plans for achieving soon a gain of 10 GeV over a length of a third of a meter.

Politics vs. Science. Many American scientists have alleged that the current administration manipulated the process through which science enters governance for political gain. Kurt Gottfried (Cornell University) and Lawrence Krauss (Case Western Reserve University) will discuss examples and evidence to support this claim, and what the scientific community might do to ensure that politics does not trump science. Presidential science advisor John Marburger will be on hand to offer the Bush administration's perspective.

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Editor: Alan Chodos
Associate Editor: Jennifer Ouellette