APS News

Philadelphia Hosts 2003 April Meeting

The APS heads to the city of brotherly love this month for the 2003 APS Spring Meeting, April 5-8 in Philadelphia, Pennsylvania. This year's meeting is also the spring meeting of the APS Division of Particles and Fields (DPF). Astrophysics comprises a strong component of the technical program, along with nuclear physics, plasma and computational physics, particle physics, gravitation, and precision measurement and fundamental constants. There are also nontechnical sessions on such topics as physics education, international affairs, physics history, and physics and society.

In keeping with the meeting's tradition of emphasizing the unity of physics, the technical program will feature nine plenary lectures providing a general overview of a broad range of topics. These will include mysteries of extra dimensions, antimatter, quantum chaos, gamma-ray bursts, and matter, space and time at the energy frontier. There will also be lectures on recent Chandra observations of supernova remnants and young neutron stars, as well as the outlook for science done underground, such as at the SNO facility in Canada.

Nobelly Yours. In addition to being the subject of a plenary lecture on SNO, solar neutrinos are among the topics to be discussed during a special session with lectures by the 2002 recipients of the Nobel Prize in Physics, along with other APS prize recipients. Masatoshi Koshiba of the International Center for Elementary Particle Physics in Tokyo-co-recipient with Ray Davis for their independent neutrino experiments—will be on hand to discuss the birth of the field of neutrino astrophysics. He will be joined by Riccardo Giacconi of Associated Universities, Inc., in Washington, DC, who will discuss his pioneering role in the development of x-ray astronomy, and James York and Yvonne Choquet-Bruhat, co-recipients of the 2003 Dannie Heinemann Prize. Finally, Princeton's John Wheeler, co-recipient of the 2003 Einstein Prize, will offer his thoughts on the origin of spacetime. [Session B6]

Never Enough Neutrinos. Providing some historical context to the topic of solar neutrinos, Allan Franklin (University of Colorado) will discuss early experiments that led to the "solar neutrino problem": the fact that the observed number of solar neutrinos was far less than predicted by the Standard Solar Model. John Bahcall (Institute for Advanced Study) will provide the theoretical perspective, while Kenneth Lande (University of Pennsylvania) will discuss the history of the Homestake Chlorine Solar Neutrino Detector. Other speakers will describe current experiments with radiochemical gallium, and the Kamioka experiments. [Session T2]

The Future of Particle Physics. The DPF will be sponsoring a Monday afternoon session at the University of Pennsylvania as part of its meeting program, exploring the future of particle physics. Noted theorist Edward Witten (Institute for Advanced Study) will be on hand to discuss theory and the future, while Peter Meyers (Princeton University) will give an overview of the next 20 months to 20 years of neutrino oscillation experiments. Homer Neal (University of Michigan) will cover the status and planned capabilities of the Large Hadron Collider currently under construction at CERN, and Michael Turner (University of Chicago) will summarize recent exciting discoveries on the composition of the universe and remaining critical questions to be answered in the 21st century. [Session R15]

Dark Energy is a SNAP. In the face of mounting evidence that the universe is accelerating, theoretical physicists are debating the implication of the existence of a new and very different type of matter in the universe: the so-called "dark energy". In a Tuesday morning session, distinguished speakers will discuss various aspects of dark energy science, focusing on two major projects. The Supernova Acceleration Probe (SNAP) is a two-meter telescope in high Earth orbit, designed to measure the time—dependent equation of state of the dark energy component. The next generation SNAP will determine the dark energy density and equation of state. Currently under construction is the Gamma-Ray Large Area Space Telescope (GLAST), a satellite-based experiment to measure the cosmic gamma-ray flux in the energy range of 20 MeV to 300 GeV. Slated to launch in 2006, GLAST is expected to open a new window on high energy phenomena, including supermassive black holes, active galactic nuclei, gamma-ray bursts, supernova remnants, and cosmic ray acceleration, as well as search for such new phenomena as supersymmetric dark matter annihilations and big bang particle relics. [Session U12]

Shaping a New Identity? Triggered by state-of-the-art nuclear physics experiments at Virginia's Jefferson Lab, the University of Mainz, and the MIT-Bates Linear Accelerator facility, physicists are revising basic assumptions about the proton and neutron. According to some nuclear theorists, the data provide evidence that the proton is not always spherically shaped but can regularly assume different shapes. Gerald Miller (University of Washington) will display pictures that show that the shape of the proton can vary from a pancake to a peanut to a sphere. Miller has also developed a new relativistic model of the neutron. Agreeing with recent Jlab data, the model shows that part of the time, a neutron is actually a proton surrounded by a negatively charged pion. Other speakers will discuss these new experiments and theories. [Session B3]

Weighty Particle Matters. Scientists at the Indiana University Cyclotron Facility have made the first unambiguous identification of a rare process: the fusion of two nuclei of heavy hydrogen to form a nucleus of helium and an uncharged pion. This process wouldn't exist without a small violation of charge symmetry-a violation which also causes to neutron to be slightly heavier than its charged partner, the proton. The rate at which this rare process occurs is expected to be a key piece of information that will point scientists toward the cause for this violation of charge symmetry. [Session C3]

Speed of Gravity. A recent controversial measurement claimed to measure the speed of gravity by looking at the gravitational lensing of a star by Jupiter. While there is no doubt that this is an impressive experiment, the interpretation of the claim that the speed of gravity can be extracted from the results is controversial. Clifford Will of Washington University in St. Louis, a leading expert in gravitational physics, will present his analysis of the problem, which indicates that the reported interpretation is flawed. [Session R12]

Telescopes of Ice. Burying string-of-pearl detectors kilometers deep in Antarctic ice doesn't sound like the usual way to make a telescope. But that is exactly what is happening with the AMANDA neutrino telescope. Steven Barwick of the University of California, Irvine, will report on the latest results from AMANDA and also discuss the upcoming ANITA experiment, which uses Antarctic ice without embedments to form the neutrino detector; instead the impacts of neutrinos are measured by an orbiting satellite looking back down at the ice. The next generation of AMANDA will be used to search the skies for gamma ray bursts. [Session P9]

Demining Detectives. Antipersonnel landmines left over from previous conflicts cause a great deal of human suffering, and while the issue has only recently received significant public exposure, the US has been investing in research to detect and defuse landmines since World War II. [Earlier this year, the APS Council approved the commission of a study on humanitarian demining provided funding can be obtained; see APS News, January 2003.]

In a Saturday afternoon session, speakers will provide an overview of the topic, covering approaches aimed at detecting the casing of landmines, and those aimed at directly detecting the explosive contents. Some techniques to be discussed include electromagnetic induction, acoustics, ground probing radar, trace explosive vapor detection, and nuclear quadrupole resonance.

For example, Caltech's Nathan Lewis will describe recent results in exploiting vapor detection technology to make a low power, low cost "electronic nose", while Surajit Sen (SUNY-Buffalo) will describe efforts to apply impulse-based imaging to detect and image small nonmetallic mines. [Session C2]

Vintage Franklin. Distinguished Founding Father Benjamin Franklin is also America's earliest model of the "civic scientist," according to Neal Lane (Rice University), one of the featured speakers at a session exploring Franklin's pioneering role in this arena. "Science was his passion and expertise, but society was his concern," says Lane. He will be joined by Harvard University's Dudley Herschbach, Claude-Anne Lopes (Yale University) and James McClellan III (Stevens Institute of Technology), all of whom will provide historical background of the scientist and citizen.

Herschbach will also be giving a special public lecture at the Franklin Institute Sunday night, entitled "Ben Franklin's Scientific Amusements". In addition, a Saturday afternoon session explores innovative ways to use science history and biography to bring physics to life in the classroom. [Sessions P1, C4]

Cultural Dichotomy. The recently reissued (2000) biography of I.I. Rabi—Rabi: Scientist and Citizen, by John Rigden-includes a footnote recounting a visit by novelist C.P. Snow at the Rabi home in New York City, during which Snow reportedly told Rabi's son that his father was the man who gave him the idea for his seminal work, The Two Cultures.

Michael Day of Lebanon Valley College in Annville, Pennsylvania, has studied the chronology of events, Rabi's published and unpublished works, and his correspondence with Snow to build a strong case for the truth of this assertion. He will present his findings in a Sunday morning session, providing an overview of Rabi's views on science and society and the mutual influence between Rabi and Snow. [Session H8]

Test Your Physics IQ. Piquing the interest of apathetic non-physics majors requires innovative educational approaches. The University of Maryland's Richard Berg has created a distinctive approach to piquing student interest: a physics IQ test. Assembled throngs vote on the outcomes of "brain-teaser" type physics questions, which are then answered by performing a demonstration experiment.

At the same session, J.C. Sprott (University of Wisconsin-Madison) will describe the outreach program he founded in 1984. Called "The Wonders of Physics", it is a series of public lectures intended to foster general interest in physics with fast-paced demonstrations, including music, costumes, skits and surprise appearances by special guests. The presentation routinely draws capacity crowds totaling over 50,000, and a traveling show was added in 1988 for school children in 19 states and provinces.

Also, Louis Bloomfield will describe a course he developed for non-science students called How Things Work, which teaches elementary physics in the context of everyday life. [Session H7]

Disarmament Goes Ballistic. Approved by the United Nations in 1996 with only three opposing votes, the Comprehensive Test Ban Treaty (CTBT) enjoys near-unanimous support by the international community. But now that India is considered a "threshold nuclear nation", it must approve the treaty if it is to enter into force, and India's U.N. representative has said the country will never sign the treaty. Ram Chaturvedi (SUNY College at Cortland) will provide an overview of the treaty's current status, including India's continued refusal to ratify it. Meanwhile, on Tuesday morning speakers will provide an overview of the current status and future prospects for the US ballistic missile defense programs, focusing on both mid-course and boost-phase technologies. [Sessions H8, T5]

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Editor: Alan Chodos
Associate Editor: Jennifer Ouellette