APS-AAPT joint meeting: Highlights

American Physical Society and American Association of Physics Teachers

Secret military projects, powerful collisions at the LHC, future international physics projects, and lots of new data from around the universe will be featured in talks at this year's spring meeting of The American Physical Society (APS), the largest professional society of physicists in the world. This year, APS is joining with the American Association of Physics Teachers (AAPT), the world's largest society of physics teachers, for a joint meeting from February 13-17, 2010 at the Marriott Wardman Park Hotel in Washington, D.C.

The APS portion of the meeting includes particle physics, astrophysics, nuclear physics, plasma physics and other physics disciplines that impact society. The AAPT portion of the meeting will showcase the latest trends in national and international physics education (should physics in high school be taught before biology?) as well as talks about the physics of hobbies -- such as running, crossword puzzles and high-altitude ballooning..

Journalists are invited to attend the meeting free of charge. Registration information can be found at the end of this release.


The items below highlight some of the interesting talks and sessions at the meeting. A second press release summarizing press conferences at the meeting will be available in early February.

  1. Large Hadron Collider
  2. Physics and Secrecy
  3. Big Plans for European Particle Astrophysics
  4. Health, Homeland Security and Nuclear Physics
  5. Powerful Emissions from Massive Galaxies
  6. Laserfest: Cascade Lasers
  7. Sounds of the Little Bang
  8. Using Sunlight to Recycle Carbon Dioxide
  9. New Japanese Experiments in Astrophysics
  10. Balloon Listens to South Pole Radio
  11. Getting a Look at the Galactic Black Hole
  12. Fans of Gamma Ray Pulsars
  13. New Map of Universe Glow?
  14. Tornado Tracks
  15. Enrico Fermi as Mentor
  16. Preview to a Nobel: the 2010 Sakurai Prize
  17. Plenary Talks
  18. More Information for Journalists


Late last year, the LHC became the most powerful particle accelerator in history, achieving proton-proton collisions at energies of 2.34 trillion electron volts. The first session of the meeting, A1, is devoted to the latest news from Geneva, where efforts are being made to further increase the beam energy and intensity (Session A1, http://meetings.aps.org/Meeting/APR10/SessionIndex2/?SessionEventID=116204).

Other sessions will take up various LHC issues that include the interpretation of collision results and instrumentation at LHC.

(Session D9, http://meetings.aps.org/Meeting/APR10/SessionIndex2/?SessionEventID=124734)
(Session B9, http://meetings.aps.org/Meeting/APR10/SessionIndex2/?SessionEventID=124732)
(Session P12, http://meetings.aps.org/Meeting/APR10/SessionIndex2/?SessionEventID=124742)


Secrecy surrounded the hidden physics laboratories of the wartime Manhattan Project and has continued to linger around many research topics related to military matters. At session B5 Harvard physics historian Peter Galison will look at the legacy of our post-Cold War secrecy systems, while Steven Aftergood, who runs a government secrecy program at the Federation of American Scientists (http://www.fas.org/sgp/index.html), will present the current landscape of secrecy. William Happer, a former official at the Department of Energy and now a professor at Princeton, will discuss how to arrive at the right balance between openness and secrecy. (Session B5, http://meetings.aps.org/Meeting/APR10/SessionIndex2/?SessionEventID=116241)


Scientists in the field of particle astrophysics -- which combines astronomy with particle physics -- study some of the most fundamental questions of the universe under the auspices of large, multinational collaborations that pull together hundreds of researchers and rely upon telescopes and other facilities that may cost millions to hundred of millions of dollars to build. Careful planning is essential for the effective use of these funds, and in the last few years, a group known as ASPERA (Astroparticle European Research Area network) has coordinated efforts to develop a strategic roadmap for the future of particle astrophysics within the European Union (EU).

In Washington D.C., the first ASPERA coordinator Stavros Katsanevas of IN2P3, the Nuclear and Particle Physics National Institute of the Centre National de la recherche scientifique (CNRS) in France, will describe the new roadmap, which settles on advancing seven large "infrastructure" projects identified as priorities for particle astrophysics -- from a large array of telescopes to detect high-energy gamma-rays to the building of a new neutrino detector at the bottom of the Mediterranean sea. Says Katsanevas, these projects would range from 50-million Euros for the smallest to about a billion Euros for the largest, and one of the big goals of the community for the next decade will be to find funding for these projects. More information of the EU roadmap can be found at http://www.aspera-eu.org. (Talk B3.1, http://meetings.aps.org/Meeting/APR10/Event/114795).


Novel nuclear physics applications range from detecting smuggled nuclear fuel to minimally invasive methods for monitoring radiation exposure to detecting pollutants on surfaces and in the environment. Session Y13 includes a number of nuclear physics innovations intended to keep us safe and healthy. (Session Y13, http://meetings.aps.org/Meeting/APR10/SessionIndex2/?SessionEventID=115965)


Giant lobes of radio galaxies are among the largest structures in the universe -- often extending into areas of space that are several orders of magnitude larger than the Milky Way. Astronomers first identified these massive structures by their radio wave emissions decades ago, and in recent years, several modern telescopes have detected higher-energy emissions from giant lobes, indicating that they are very efficient particle accelerators.

Lukasz Stawarz (KIPAC/SLAC, Stanford University) will present the current scientific understanding of the processes that take place in the giant lobes and lead to these high-energy emissions. In order to produce the observed X-ray and gamma-ray emissions, he says, particles within the lobes must be accelerated to extremely high, ultrarelativistic speeds. He will discuss the most recent observations from the Chandra X-ray Observatory, the Pierre Auger Observatory, and the Fermi Gamma-Ray Telescope, including evidence that the lobes of nearby radio galaxies -- in particular the Centaurus A radio galaxy -- are the sources of the highest energy cosmic rays ever detected on Earth. (Talk H3.3, http://meetings.aps.org/Meeting/APR10/Event/115161).


LaserFest celebrates the fiftieth anniversary of the invention of the laser this year with a series of presentations given at several scientific meetings. At the APS meeting, for example, Session X4 explores the impact of lasers on precision measurements. One talk will recount the invention of the original 1960 ruby laser. Another will look at frequency comb metrology, a technique that measures laser wavelengths with high precision. A third looks at quantum cascade lasers, which metaphorically put electrons in a barrel and send them over a series of waterfalls. Instead of recombining with holes to create one photon per electron, as in conventional semiconductor lasers, electrons in a QC laser pass through a succession of closely coordinated quantum wells -- sandwiches of semiconductor layers -- and unload energy as they go in the form of one photon per stage in the stack. (Session X4, http://meetings.aps.org/Meeting/APR10/SessionIndex3/?SessionEventID=116197).


Particle accelerators at Brookhaven National Laboratory and CERN that collide large nuclei, like gold or lead, create very small systems with densities and temperatures similar to that of the universe when it was a microsecond old. These collisions produce a small speck of matter through which acoustic waves can propagate. Agnes Mocsy (Pratt Institute) will present an analysis of the acoustic signatures left over from these relativistic high-energy collisions. By shifting the frequencies to an audible range she will allow the audience to hear the evolution of these little bangs created in the laboratory. This is the first time relativistic particle collisions have been presented as a sound. (Talk Y14.7, http://meetings.aps.org/Meeting/APR10/Event/115984)


Every year factories across the world pump some 10 billion tons of carbon dioxide into the atmosphere. A new technique could allow the industrial sector to convert this greenhouse gas into useful commercial products using sunlight.

Stuart Licht, a chemist at George Washington University in Washington, D.C., uses solar-generated electrical currents to split apart molecules of carbon dioxide. The process, called Solar Thermal Electrochemical Photo (STEP), produces oxygen and carbon monoxide, a gas needed to make commercial methanol.

Using electrical currents to split molecules apart isn't a new idea. Hydrogen fuel, for example, can be made by running a current through water to split it into hydrogen and oxygen. But Licht improves this process, called electrolysis, by adding heat from the sun. When sunshine strikes a solar panel, only a fraction of it generates electricity. The rest radiates away as waste heat. STEP harnesses this thermal energy to heat up a reaction, improving its efficiency by lowering the amount of electrical energy needed to split bonds.

The technique boosts the efficiency of hydrogen production from 18 to 30 percent; the energy R&D company Lynntech is applying this process to generate hydrogen for fuel cells. In the laboratory, Licht has converted concentrated carbon dioxide to carbon monoxide at 50 percent efficiency. (Talk G10.1, http://meetings.aps.org/Meeting/APR10/Event/115102).


For all the massive stars, galaxies, nebulae, and other visible objects in the universe, there is much more matter we cannot see. When compared to all the visible material in the universe, this mysterious "dark matter" accounts for about 5-6 times more mass, and numerous astrophysical experiments seek to detect it directly or indirectly. One direct approach involves using liquified noble gasses like Xenon to detect the light given off when a dark matter particle interacts with a Xenon nucleus.

A forthcoming Japanese experiment called XMASS will look for such interactions within a vat filled with a ton of liquid Xenon placed inside a 200,000-gallon water tank buried deep in the Kamioka mine in Japan. It promises to be 100-times more sensitive than other experiments searching for dark matter, says Hitoshi Murayama, the director of the Institute for the Physics and Mathematics of the Universe at the University of Tokyo. In Washington, D.C., Murayama will present a talk on the status of XMASS, which is expected to be online early in 2010. He will also discuss other future projects in Japanese astroparticle physics, including a proposed 900-million pixel camera for the Subaru telescope in Mauna Kea, HI and a project aimed at building a 3D map of the dark matter in the visible universe. (Talk B3.3, http://meetings.aps.org/Meeting/APR10/Event/114797).


An Antarctic penguin looking up into the sky in 2008 might have seen the ANITA Long Duration Balloon circling high above, monitoring the ice below with the radio antennas mounted onboard. The balloon, on its second flight, was looking for an elusive, ghostly cosmic particle called an ultrahigh energy neutrino. At the February APS meeting, researchers from the ANITA project will present their analysis of the data from this flight.

Ultrahigh energy neutrinos are thought to be created when cosmic rays in distant galaxies collide with the cosmic microwave background. These cosmic rays cannot travel very far, but neutrinos can -- offering astrophysicists a way to indirectly study cosmic rays that are very far away, created long ago.

Neutrinos barely interact with matter -- they can pass through entire planets. But on occasion, when one touches an atom in a bit of ice, it should create radio waves that shoot through and out of the ice. The ANITA balloon watched more than a million cubic kilometers of Antarctic ice for these telltale radio waves, transforming the frozen continent into a gigantic neutrino detector.

On its first flight, the balloon did not detect any ultrahigh energy neutrinos -- but it did detect radio waves produced by ultrahigh energy cosmic rays. "These ultrahigh energy cosmic rays demonstrated our capacity to see events of this sort, to see neutrinos," says Stephen Hoover of the University of California, Los Angeles.

The data to be presented from the second flight has the potential to include the first detection of cosmic ultrahigh energy neutrinos or, if not, to set an upper limit on how many of them are passing through the Earth. (Talk H13.1, http://meetings.aps.org/Meeting/APR10/Event/115237), (Talk H13.3, http://meetings.aps.org/Meeting/APR10/Event/115239)


Three invited talks in Session D4 focus on research into various aspects of the black hole that a growing number of scientists believe resides at the center of our galaxy: David Merritt (Rochester Institute of Technology) describes how we can probe strong-field gravity at the galactic center by looking at the motion of nearby stars (http://meetings.aps.org/Meeting/APR10/Event/114957), Sheperd Doeleman (MIT Haystack Observatory) will outline progress toward imaging the galactic black hole with Very Long Baseline Interferometry (http://meetings.aps.org/Meeting/APR10/Event/114955), and Avery Broderick (Canadian Institute for Theoretical Astrophysics) will describe what we expect to see with the VLBI if we find a black hole as expected. In Talk H14.6, Laleh Sadeghian and Clifford Will (Washington University) explain what evidence will prove once and for all that there is indeed a black hole at the galactic center (http://meetings.aps.org/Meeting/APR10/Event/115252).


Most pulsars -- rotating neutron stars that emit beams of electromagnetic radiation -- were originally discovered by radio telescopes. That's because most of the 1,900 or so known pulsars in the universe emit radio waves, and very few have been found to emit more powerful beams of X-rays or gamma rays. That number has been increasing in recent months thanks to observations from the Fermi Gamma-ray Space Telescope (formerly GLAST), and these observations are helping physicists characterize pulsars that emit in gamma rays.

Lucas Guillemot of the Max-Planck-Institut f-r Radioastronomie will present a summary of pulsar observations in gamma rays with the Fermi Large Area Telescope (LAT) during its first year and a half of operation. Before Fermi was launched, fewer than ten gamma ray pulsars were known. "The great efforts of the Fermi LAT team supported by observations made at radio and X-ray telescopes led to the detection of 55 pulsars in gamma rays since June 2008, and this number will continue to increase," says Guillemot. In addition to those 55, the LAT is now detecting many unidentified sources that might point to yet unknown pulsars.

Scientists like Guillemot hope the data will help define some of the physical characteristics of these pulsars, such as how and where around the star the gamma rays are produced. The data is already showing that when pulsars emit gamma rays, they seem to do so in fan-like beams that sweep large sky fractions, suggesting that they are produced at high altitude in their magnetospheres. This differs from radio beam shapes emitted by pulsars, which tend to be cone-like and centered on the magnetic axis of the neutron star. (Talk, A3.1, http://meetings.aps.org/Meeting/APR10/Event/114691)


For nine years, NASA's Wilkinson Microwave Anisotropy Probe (WMAP) has measured the Cosmic Microwave Background (CMB) -- a soft, nearly-uniform glow that fills the universe. The most accurate and precise measurements of the cosmological parameters come from WMAP data, which is at the foundation of the standard cosmological model. Continued analysis of the data is helping cosmologists better understand how stars and galaxies came to be arranged after the Big Bang.

The first full-sky map from WMAP in 2003 firmed up the universe's age and rate of expansion and confirmed the existence of dark matter and dark energy. A second map in 2005 revealed a polarization to the CMB that pushed back the date of the formation of the first stars. A third map is 2007 firmed up the standard model and was used to constrain the properties of neutrinos.

"The standard cosmological model is in very good shape," says Lyman Page of Princeton University. "We're entering another era of analyzing the cosmic microwave background and looking for something that is peculiar."

"With the standard model as a foundation, we are also searching for gravitational radiation left over from the Big Bang and quantifying the role of neutrinos in the universe," Page adds. (Talk Y3.2, http://meetings.aps.org/Meeting/APR10/Event/115888)


A small fraction of severe storms produce violent tornadoes, concentrating violent winds within tens of meters above the ground. Here the threat to human life and property is highest and interaction with the surface can significantly affect the intensity of the tornado; yet, this portion of the flow is very difficult to measure in the field. As part of a longstanding research effort using computer simulations to study tornado and tornado debris cloud dynamics, physics grad student Michael Zimmerman and research professor David Lewellen of West Virginia University have recently been investigating surface marks that simulated tornadoes leave behind as they move fine debris about. They hope to combine their estimates of near-surface tornado sizes and wind speeds with Doppler radar data in the field to help tornado researchers acquire more-complete measurements of tornado winds. (Talk K10.6, http://meetings.aps.org/Meeting/APR10/Event/115340)


A stellar array of physicists recount working with Enrico Fermi at the University of Chicago in the 1940s and 1950s. Speakers include Tsung-Dao Lee, who won the Nobel Prize for his work on parity violation; Richard Garwin, who did crucial work on the development of the hydrogen bomb and in many areas of physics; and Jerome Friedman, former APS president and Nobel laureate celebrated for his experimental discovery of quarks. The session is chaired by Nobel laureate James Cronin. (Session J1, http://meetings.aps.org/Meeting/APR10/SessionIndex2/?SessionEventID=116136)


The APS 2010 Sakurai Prize will be awarded to six physicists who have been instrumental in developing the theory predicting the existence of the Higgs boson. In effect, it's their theoretical work that the LHC was built to check. If the search is successful, the chances are very good that one or more of the 2010 Sakurai prizewinners will eventually share the Nobel Prize for Physics. The Nobel Prize is never awarded to more than three people, but many physicists feel that all six of the Sakurai Prize winners deserve to share in the credit. Fortunately, the APS is able to recognize all of them equally. Session P1 includes invited talks by five of the Sakurai Prize winners: Carl R. Hagen, Francois Englert, Gerald S. Guralnik, Peter W. Higgs, and T.W.B. Kibble. The sixth recipient, Robert Brout, will not be speaking. (Session P1, http://meetings.aps.org/Meeting/APR10/SessionIndex2/?SessionEventID=116323)


The APS meeting will provide three sessions looking at some of the premier physics topics of the day. These include:

Source: American Institute of Physics


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
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