July 2008 Volume 17, No. 7 www.aps.org/publications/apsnews APS NEWS Election Preview A PublicAtion of the AmericAn PhysicAl society • www.APs.org/PublicAtions/APsnews Page 6 2008 US Physics Team Training Camp: Sights Set on Vietnam By Nadia Ramlagan brightest, most disciplined high tial nominee John Kerry. Students school physics students in the also presented a physics‑related Richard Berg of the University United States. Five of these stu‑ toy to their own Senators and of Maryland is standing on top dents will be chosen to represent Representatives. of a desk, one arm outstretched the US at the 67th International “Only special kids get to this and grasping a slinky. The bottom Physics Olympiad July 20‑29 in level of math and physics, they end isn’t touching the ground. Hanoi, Vietnam. have to push themselves. This What happens to the bottom end The daily routine is intensive, means doing extra problems on if the upper end is released? An studying physics from 8:00 a.m. to their own time. The most reward‑ eager group of hands shoots up 9:30 p.m. “I wish we could sleep ing aspects of this experience in the air. Welcome to the 2008 in at least one day,” says Tucker are interacting with the kids, and US Physics Team training camp. Chan, a senior from Princeton pushing them further intellectu‑ The students were responding to High School in Princeton, NJ. ally. Many times they push you,” Berg’s question during his phys‑ The week consists of 5 mystery says coach David Jones, an in‑ ics IQ test lecture, one of the labs, 7 exams, and daily lectures structor at Florida International many entertaining but challeng‑ on oscillations, waves, relativity, University and high school teach‑ ing events the team will experi‑ and thermodynamics. er of 20 years. ence during its 10‑day stay at the Scattered throughout the week The students, ranging from campus in College Park. were games, including frisbee freshmen to seniors and coming The 24 students attending most nights, and a trip to Con‑ from a variety of backgrounds, camp were selected through a gress in Washington DC, where are enthusiastic about camp, ready Photo by Nadia Ramlagan highly competitive elimination the students toured the city and to absorb as much information as Richard Berg challenges the members of the US Physics Olympiad team to pre- process, and they represent the met former Democratic presiden‑ CAMP continued on page 5 dict what will happen when he drops the slinky. PhysicsCentral Takes on a New Look and Feel Finalists Vie for APS Industrial Physics Prize When PhysicsCentral, the of the public with an interest in The site now features its own blog, Five finalists are competing for spun off from Bell Labs in 2000 to APS website for the public, was science, especially students at all Physics Buzz, and APS Head of the first APS Prize for Industrial Ap‑ commercialize a unique chemistry launched in late 2000, the web was levels from middle school through Public Outreach Jessica Clark, plications of Physics, launched this for the storage media and the archi‑ a very different place. The original university. Rather than do it piece‑ who runs PhysicsCentral, is busy year. As reported in the January APS tecture for a holographic drive, with PhysicsCentral (below, left) was meal, it was decided last year to collecting a series of podcasts and News, the prize, sponsored by Gen‑ a storage lifetime of 50 years and all text and pictures, with an occa‑ undertake a complete redesign. vodcasts that will augment the text eral Motors and presented biennially, density and cost comparable to mag‑ sional animated gif to liven things The new PhysicsCentral was and pictures format of the earlier is intended to recognize cutting‑edge netic tape. However, the most daunt‑ up. But now the web is filled with launched in May, and as can be material. technologies, and is especially target‑ ing remaining challenge was finding ed at physicists working in smaller a light source for the drive. Commer‑ companies. cial holography requires a laser with To encourage nominations, the spectroscopic quality, in a small ro‑ selection process has two stages: first, bust package that costs a small frac‑ preliminary nominations are submit‑ tion of the total $18,000 drive. ted by the deadline of April 1. The ECLDs have been used since the selection committee picks a small early 1990s to apply semiconduc‑ number of finalists, who then submit tor laser diodes to high‑resolution more complete nomination packages spectroscopy, but while the perfor‑ by July 1, from among which the mance specifications met InPhase’s committee will recommend the re‑ needs, the cost to scale up efficiently cipient to the APS Executive Board. to manufacturing volumes was too This year 16 preliminary nomina‑ high: Ensher and Hunter aimed for a tions were received. “I was delighted cost 10 times lower than ECLDs of Before After that there were so many nominations comparable performance. The usual of high quality,” said Greg Meisner, approach is to make the ECLD con‑ podcasts and vodcasts, blogs and seen by comparing the two pic‑ “A lot of work went into the the selection committee chair. “But it tinuously tunable in a single mode RSS feeds, words that didn't even tures, the look is very different. redesign,” says Clark. “The new made choosing the finalists very dif‑ using an expensive cavity and very exist back then. Underneath the design is a dy‑ site is interactive with tons of ficult.” precise tuning mechanism. Ensher Clearly PhysicsCentral needed namic architecture that accesses fun new features which will en‑ The finalists selected by the com‑ and Hunter realized it would be an upgrade if it wanted to main‑ the content more efficiently and gage all levels of users, from K mittee are: much cheaper to design a cavity that tain its core audience of members brings more of it to the home page. to grey.” Jason Ensher and Susan Hunter minimizes laser mode‑hops that can Jason Ensher and Susan Hunter also detect when the laser mode is DAMOP Holds Annual Meeting in State College, PA applied tunable External Cavity La‑ degrading thanks to the incorpora‑ ser Diodes (ECLDs) to holographic tion of a mode sensor combined with Recent progress towards achiev‑ proaches to achieving a viable quan‑ photons in a solid state environment. data storage. Holography holds great a digital control algorithm. ing quantum storage in solid state tum memory. Matthew Sellars of His ensembles employ rare‑earth potential for storing information be‑ Ensher and Hunter’s ECLD au‑ devices, manipulating single‑elec‑ the University of Otago described a ions–a “frozen gas of atoms”–doped cause holograms can be multiplexed tomatically senses the laser mode tron spins in quantum dots, and laser method for storing light that operates into dielectric crystals, which can in in three dimensions, rather than be‑ and feeds back this information to cooling of mechanical oscillators by controlling the local group veloc‑ principle store single photos and re‑ ing limited to the surface of the stor‑ correct the laser cavity length–they were among the highlights of the ity of light in a crystal, using an ap‑ call them with high efficiency using a age medium. InPhase Technologies PRIZE continued on page 5 2008 meeting of the APS Division plied electric field. He maintains that modified photon echo approach. Dif‑ of Atomic, Molecular and Optical unlike other proposals for quantum ferent wavelengths of absorption can Physics (DAMOP), held 27‑31 May memories, his method requires no be achieved depending on the choice in State College, Pennsylvania. optical control pulses, thereby sim‑ of rare‑earth ions employed. De Quantum Memory. Quantum plifying the operation of the memory Riedmatten finds that erbium‑doped VOTE in the APS News memories are likely to be critical and improving its signal to noise. solids are an especially attractive components in any future long‑range Hugues de Riedmatten of the candidate for a quantum memory at Caption Contest!! communications network, and sev‑ University of Geneva is develop‑ telecommunication wavelengths. eral talks at the DAMOP meeting ing atomic ensembles to realize a The “holy grail” of research into See page 4 focused on various methods and ap‑ quantum storage device for single DAMOP continued on page 3 2 • July 2008 APS NEWS Members in the Media This Month in Physics History July 1820: Oersted and electromagnetism “Most every problem you National Geographic News, y the end of the 18th century, scientists had Some people have suggested that this was a can imagine has been solved by May 16, 2008 Bnoticed many electrical phenomena and totally accidental discovery, but accounts differ on nature. Nature got there first. many magnetic phenomena, but most believed whether the demonstration was designed to look for All that is left is to rationalize “We’re motivated by the that these were distinct forces. Then in July 1820, a connection between electricity and magnetism, or nature’s designs, many of which physics questions we’re trying Danish natural philosopher Hans Christian Oersted was intended to demonstrate something else entirely. are remarkably subtle.” to answer, and we’re willing to published a pamphlet that showed clearly that they Certainly Oersted was well prepared to observe such John Bush, MIT, Boston move heaven and Earth to get were in fact closely related. an effect, with the compass needle and the battery Globe, May 19, 2008 the experiment built to answer Hans Christian Oersted was born in August 1777, (or “galvanic apparatus,” as he called it) on hand.