April 15, 2007

2007 April APS Meeting

College Park, MD — The April Meeting of the American Physical Society (APS) will occur April 14-17, 2007 at the Hyatt Regency Riverfront Hotel in Jacksonville, Florida. This is the second of the two largest general physics meetings of the year. The first one, the APS March Meeting, takes place March 5-9 and is concerned with condensed matter, chemical, and biological physics. At the April Meeting, by contrast, the big topic areas are particle, nuclear, astro, and plasma physics. In addition there will be a wide variety of session devoted to education, national security, energy research, and other social issues. Examples include the popularization of science (session B5) with speakers such as Lawrence Krauss (“Physics of Star Trek” and “Hiding in the Mirror”) and Brian Greene (“The Elegant Universe” and “The Fabric of the Cosmos”); a talk by the man, Sam Pitroda, who heads India's National Knowledge Commission and is regarded as the father of that nation's communications revolution (M10.3); and a session (K5) on the current role of nuclear weapons in establishing foreign policy. Other notable speakers include James Hansen (NASA) on climate change, Amory Lovins (Rocky Mountain Institute) on energy efficiency, and the 2006 physics Nobelists John Mather (NASA) and George Smoot (LBL) on the cosmic microwave background.

The April Meeting website is http://meetings.aps.org/Meeting/APR07/APS_epitome. Click on "epitome" to see the meeting program, including abstracts. One can search by topic, name, or affiliation. Complimentary press registration will allow science writers to attend all scientific sessions. Public information officers, as usual, are welcome. If you wish to come, please reply to Phil Schewe at pschewe@aip.org. Here is information relating to the press operations at the meeting:

  • The meeting pressroom will be located in the Hyatt Regency Riverfront Hotel, St. John’s room
  • Press conferences will take place in the Board Room 1.
  • Pressroom hours: April 13-16, AM to 5 PM and April 17 until noon.
  • Pressroom phone numbers:904-360-8569, 8570, 8571, 8572
  • Pressroom fax number: 904-360-8573
  • Internet hookups will be available.
  • Breakfast and lunch food will be available in the pressroom Saturday-Monday
  • a press conference schedule will be issued around April 2.


The Relativistic Heavy Ion Collider (RHIC) at the US Department of Energy's Brookhaven National Laboratory has been taking a break from its experimental efforts to re-create the conditions of the early universe. During the past year, RHIC has been investigating the origin of the proton’s spin, the property that gives the proton its internal magnetism and allows Magnetic Resonance Imaging (MRI) to work. The origin of this spin remains a mystery. The proton gets only about 25 percent of its total spin from its quarks (which includes not only its three main "valence" quarks but also the quark-antiquark pairs that blink in and out of existence inside the proton's confines). The remaining 75 percent might come from the proton's gluons, which hold together the quarks and from orbital motions of quarks and gluons in the proton. With help from the RIKEN Institute in Japan, RHIC has been converted part-time into the world's only collider of proton beams with spins that are "polarized" or pointed in desired directions. Nuclear physicists at RHIC are now studying the aftermath of high-energy proton-proton collisions to infer the role of gluons and of orbital quark motion in building the proton spin. RHIC collaborator Steven Vigdor of Indiana University will present preliminary experimental results on these investigations. (W1.3)

More than a decade after physics researchers created the World Wide Web as a way of exchanging data between far-flung research institutions, high-energy physics continues to exert a profound influence on the evolution of the Internet. Now, physicists want to ensure that fast Internet access is available to all collaborators, including those in developing countries. With experiments at the Large Hadron Collider (LHC) experiment expected to produce about 10 petabytes (or 10 million gigabytes) of data each year for more than a decade, a newly developed high-speed "grid" network of 100 computing centers can transmit LHC data at an amazing rate of 10 gigabits per second (an order of magnitude faster than the communication rate between a laptop CPU and its own hard drive) between the dozen fastest centers, and the speed is expected to increase rapidly in future years. Such high-speed networks, in turn, benefit the overall communications infrastructure for research institutions even for projects outside of physics. However, physicists are concerned that high-energy-physics collaborators in developing nations might not have access to the large bandwidths needed to handle the huge amounts of data from the collider. Presenters in two sessions (M10 and R9) will discuss efforts to reduce this digital divide. Harvey Newman of Caltech (newman@hep.caltech.edu) will present an introduction to this problem as well as the findings of a major new report exploring this issue. Other talks will present programs to close the digital divide in Latin America (R9.1), South Africa (R9.3), India (M10.3) and Pakistan (R9.4), and the building of a "Virtual Silk Highway" (R9.2) that has brought about fast communications networks to Afghanistan and eight Former Soviet Republics.

Stanford University's Francis Everitt will outline the preliminary results of the $750 million Gravity Probe B mission, possibly the longest-running, most expensive single experiment in history. GP-B is a NASA mission first envisioned in the early 1960s and launched in April 2004. It aims at directly measuring a subtle effect of Einstein's general relativity for the first time. The effect, called frame dragging, is a distortion of space caused by Earth's rotation around its axis, which is expected to deflect the spinning axis of a gyroscope by such a small angle that it would take more than a million years for the gyroscope to turn in a full circle. Following several more months of data analysis, the GP-B team expects to announce its final results by the end of the year. PARTICLE PHYSICS The effort to map nature at the finest spatial scale (10^-18 meters), to grapple with the elemental forces and symmetries of nature, and to fill out the family tree of material particles is the mission of high energy particle physics. At the April meeting, a myriad of these forces and particles get their own sessions, including the top quark (sessions J14, K14, R14, T14, X13), bottom quark (H4, H14, J13, U14, X4, Y13), neutrinos (B10, H2, K11, M2, R4, R15, T4, U13), dark matter (B13, E14, H3, T12), charm quark (B14, E5), weak force (B16), strong force (C2), CP violation (H13), W bosons (E13), dark energy (J4, K4), the Large Hadron Collider (C4, R13), the International Linear Collider (B4), and laser driven acceleration (T9.1).

Researchers have combined data from the Arecibo radio antenna in Puerto Rico and the Dominion Radio Astrophysical Observatory interferometer in Canada to produce a stunning view of the sky above the plane of our galaxy. In particular, the image shows a surprising lack of correlation between the faint radiation produced by particles accelerated in the magnetized plasma of space and the distribution of bright stars and galaxies in the nearby universe. The work also offers insights into the origin and nature of some cosmic rays, into how intergalactic ultra-high energy cosmic rays might propagate, and provides a preview of the Galactic and extragalactic features that might contribute to the cosmic microwave background (CMB) on scales to be imaged by the PLANCK CMB Explorer, which NASA and the European Space Agency are jointly planning to launch later this year. Philipp Kronberg (Los Alamos National Laboratory) will present the images resulting from the combined radio data, as well as other insights to come out of the project, in paper H11.4 (Sunday, April 15, 9:06AM).

Recently, Rudolf Grimm of the University of Innsbruck and his colleagues provided the first experimental demonstration of an atomic phenomenon, first predicted in 1969, known as the Efimov effect. An entire session, B8, will be devoted to this newly observed phenomenon. In the Efimov effect, two atoms which usually repel each other become attracted when a third atom is introduced. The trio can then form an infinite number of "bound states," or energy states in which the atoms are stuck to one another. Atoms entering the Ekimov state veer from their original chemical identities; they behave differently in the company of two other atoms. Grimm will describe his collaboration's experimental demonstration, which involved cesium atoms cooled to ultracold temperatures of just nanokelvins. Also speaking will be the University of Colorado's Chris Greene, who predicted with a coauthor that ultracold atomic gases would be the ticket to observing this elusive effect experimentally. Paulo Bedaque of the University of Maryland will describe how the Efimov effect at the scale of the nucleus can provide insights into the theory of nuclear forces.

In efforts to better understand how the universe evolved into a place with distinct particles and forces, researchers at the US Department of Energy's Jefferson Lab have been performing the Primakoff Experiment (PrimEx). PrimEx is making new precision measurements of the lifetime of a short-lived subatomic object known as the chargeless pion, which can be imagined in simplest terms as a quark-antiquark pair. Before it decays into other particles, the chargeless pion exists for only an attosecond (a billionth of a billionth of a second), a thousand times shorter than predicted by early particle theory. Newer theories come closer to this observed result by taking into account chiral symmetry breaking, a phenomenon in which a configuration of nuclear particles and its mirror image do not always behave as mirror images of one another even when researchers perform identical experiments on them. In PrimEx, researchers aim a photon beam at a nucleus, which perpetually has a cloud of photons around it. Two photons--one from the nucleus and another from the photon beam--interact and make a chargeless pion, which decays into two photons. Measuring the photons provides lifetime information on the pions, with the ultimate goal of obtaining more information on the process of chiral symmetry breaking. Ashot Gasparian of North Carolina A&T State University will present the latest results on PrimEx. (Paper B2.1)

Three sessions (A1, Q1, W1) are devoted to eminent speakers holding forth on the leading topics of the day. Francis Everitt will present new results form the Gravity Probe B mission (see above item). Allan MacDonald (Univ Texas ) will describe the amazing properties of electrons moving about in a two-dimensional graphene sheet. Gerald Gabrielse (Harvard) will discuss his new measurement of the electron’s magnetic moment, which resulted in a new value for the fine structure constant. (Gabrielse’s work was deemed the physics story of the year for 2006 by Physics News Update---http://www.aip.org/pnu/2006/split/804-1.html). David Spergel (Princeton) will review the implications for cosmology of the WMAP mission, which provided recently such a fine map of the cosmic microwave background. Steven Chu (director of the Lawrence Berkeley National Lab) discusses the role played by physicists in the development of clean energy sources. Shamit Kachru (Stanford) will look at how string theory addresses the idea that many universes might exist simultaneously, each with its own fundamental “constants.” Jacqueline Hewitt (MIT) will speak about the early “dark age” in the universe; James Hansen (NASA Goddard Institute for Space Studies) will discuss global warming and its possible side effects; and Steven Vigdor (Indiana) will report on recent proton spin results from the Relativistic Heavy Ion Collider (RHIC).

Newton’s laws should break down at some point, giving way to quantum mechanics under some circumstances and relativity at others, and perhaps even yielding to some as yet unknown physical laws somewhere along the way. But just where Newtonian physics crumbles isn’t clear. As a result, many researchers have dedicated themselves to tracking down the limits of classical dynamics. Several groups report in session K12 on their efforts to put Newton to the test by searching for unusual gravitational effects at distances below a millimeter (Andrew Geraci, Stanford, K12.2); measuring the distance to the moon with millimeter precision via laser ranging (James Battat, Harvard, K12.3); and testing to see if Newton’s second law, F=ma, holds when accelerations and forces are extremely small (Stephan Schlamminger, University of Washington, K12.1). There’s no sign that anyone has succeeded in pinning down the precise limits to Newtonian physics, but all the testing is helping to eliminate exotic theories that attempt to explain away things like dark matter. The experiments are also often the source new records in precision measurements of fundamental physical laws. ENERGY TALKS Even if fossil fuels are not phased out, new means of electricity production, ones that send greenhouse gases into the air, will have to be found. Two sessions look at energy policy. At session C5 Ernest Moniz (MIT), formerly Undersecretary of Energy and E. Michael Campbell (General Atomics) look at nuclear power, while Ruth Howes ((Marquette Univ) looks at energy storage technology, such as flywheels and batteries. At session R5 Amory Lovins (Rocky Mountain Institute) reports on the latest energy efficiency methods used in industry and in the building up of distributed renewable sources of energy, such as solar and wind power. Leon Glicksman (MIT) looks at energy efficiency in buildings. He makes that point that “residential and commercial buildings constitute the largest energy consumption sector of the U.S. Buildings use almost 40 percent of our total energy, and are larger than the transportation sector by far.”

The diversity of creatures crawling, flying, and swimming across our planet may stem in part from the motion of the solar system through the galactic plane because the radiation that reaches the Earth varies as a result of our location in the galaxy. The fact that episodes of large scale extinctions on the planet seem to match the 62 million year cycles of the solar system’s motion suggests that evolution may be driven by fluctuations in the radiation that the Earth receives. In a series of papers (E11.6, E11.7, and E11.8), University of Kansas researchers Bruce Lieberman, Mikhail Medvedev and Adrian Melott investigate several kinds of astrophysical radiation sources that affect life on Earth. In extending work they presented at the 2006 April APS meeting, the researchers generalize their earlier computations to improve their insight into the effect of the radiation on the atmosphere. Among other results, they have found that the duration of the radiation exposure makes very little difference. From millisecond gamma ray bursts to 3-year increases in radiation, the ultimate amount of ozone depletion (and the resulting impact on species) is dependent primarily on the total amount of energy dumped in the atmosphere.

People in the general population don’t often go in search of science, so some physicists are taking science to the people. Brian Schwartz (Graduate Center of CUNY) will describe the outcomes of some creative science popularization efforts, including a city-wide science festival in New York last November and hands-on physics demonstrations at a New York City street festival in June of 2006 (B5.2). Hugh Haskell (North Carolina School of Science and Mathematics) is interested in a more rough and tumble physics educational effort - he works with the National Young Physicists’ Tournament (NYPT), which is modeled on a Russian physics competition started in the 1970s, but is new to the US. Groups of students involved in the tournament tackle a scientific question by developing a theoretical model to address it, performing an experiment to test their theory, and ultimately defending their work while critiquing the research of other groups. The top team in the bare-knuckle physics competition goes on to battle students from 25 other nations in the international stage of the tournament. Haskell and colleagues believe the NYPT ultimately helps build both better physics students and better teachers (paper C10.1). PHYSICS HISTORY Max Jammer (Bar-Ilan University), a distinguished physicist and author of notable books about fundamental physical properties like mass and space, is the winner of the Abraham Pais Prize Lectureship. Unable to attend the meeting himself, his paper, on the subject of how our modern concept of time came to be (paper U6.2), will be read out at the session. How the standard model of particle physics came to be so standard will be the subject of Michael Riordan’s (UC Santa Cruz) talk in session E10. He contends that the crucial years were 1964-1979, when a series of decisive experiments and incisive theoretical work came together. Other historical talks of interest concern such topics as Albert Einstein’s trip to New York City in 1921 (R10.2), the Heisenberg uncertainty principle, early photons in the early universe (Virginia Trimble, UC Irvine, paper E10.5), and a history of arms control prepared by officials at the US State Department (paper R10.6). Session T6 looks at Sputnik, the 1950s, and the founding of NASA.


About APS

The American Physical Society (www.aps.org) is a non-profit membership organization working to advance and diffuse the knowledge of physics through its outstanding research journals, scientific meetings, and education, outreach, advocacy and international activities. APS represents over 51,000 members, including physicists in academia, national laboratories and industry in the United States and throughout the world. Society offices are located in College Park, MD (Headquarters), Ridge, NY, and Washington, DC.

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