Monthly Archives: October 2010

China builds fastest supercomputer to date

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New York Times: China has built the fastest-ever supercomputer, the Tianhe-1A. It has 1.4 times the horsepower of the current top computer, built by the US, as measured by the standard test used to gauge how well the systems handle mathematical calculations. Tianhe-1A’s number-one spot is expected to become official on 1 November when Jack Dongarra, the University of Tennessee computer scientist who maintains the official supercomputer rankings, releases an updated list. For decades the US dominated the technology and built the largest, fastest machines—although Japan briefly took the title away in 2002 with a computer that had more horsepower than the top 20 American computers combined. The US quickly regained the leadership in 2004, and kept it, until now. Supercomputers are used to solve problems in areas critical to national interests, such as defense, energy, finance, and science.

Astronomers estimate the number of Earth-sized planets in the Milky Way

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Science: Although astronomers have found nearly 500 extrasolar planets, or exoplanets, in our galaxy, the impressive sample lacks an exoplanet whose mass and orbit match our Earth’s. The latest advance in the quest to find an exo-Earth is a paper in today’s Science. Andrew Howard of the University of California, Berkeley, and his collaborators report the results of a spectroscopic survey of 166 sunlike stars. The survey, which was undertaken using the HIRES instrument at the W. M. Keck Observatory on Mauna Kea, Hawaii, was sensitive to exoplanets whose orbital periods are 50 days or less. Planets with longer orbits are harder to detect. Thanks to the quantity and quality of the survey data, Howard and his collaborators could determine the exoplanets’ mass distribution. Their conclusion: Contrary to certain models of planet formation, 23% of stars harbor a close-in Earth-mass planet. The survey also implies that NASA’s planet-hunting Kepler observatory, which was launched last March, should find 120–260 of those planets around sunlike stars.

China resumes export of rare earths

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New York Times: Chinese shipments of lanthanum, neodymium, and other rare-earth elements appear to have restarted, reports Keith Bradsher of the New York Times. In a show of strength that lacked an officially avowed motive, the Chinese government had blocked the export of the industrially important minerals to Japan on 21 September and to Europe and the US on 18 October. Although the Chinese gave no explanation for the resumption, Bradsher noted that

The decision came a day and a half after Secretary of State Hillary Rodham Clinton announced plans to visit China on Saturday. She met on Wednesday in Honolulu with Japan’s foreign minister, Seiji Maehara, and said afterward that the suspension of shipments had been a “wake-up call” and that both countries would have to find alternative suppliers.

Did ice ages trigger the evolution of animals?

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Science: Twice in Earth’s past, the planet was covered almost completely in ice. Those episodes coincide with the rise of oxygen-breathing animals. Coincidence? Not according to a paper in today’s Nature. Noah Planavsky of Woods Hole Oceanographic Institution in Massachusetts and his colleagues report the results of measuring the phosphorous content of iron-rich minerals that formed long ago in the oceans. The P content of the rocks reflects the P content of the surrounding seawater at the time of their formation. Ordinarily, iron-rich rocks form with roughly the same P content, but Planavsky and his team noticed two strong exceptions: the two periods just after the extensive glaciations. In Planavsky’s scenario, the retreating glaciers ground up rock, which was flushed into the sea, raising both the P content of contemporaneously formed rocks and, through P’s fertilizing effect, the oxygen output of marine algae. Elevated levels of atmospheric O could have given a kickstart to the evolution of animals.

Polson High School students use primitive bows to study physics

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Missoulian: Jon Petersen, a physics teacher at Polson High School in Missoula, Montana, has come up with a local way to teach a universal concept. To get his students to understand elastic potential energy, he teamed up with Francis Cahoon, a member of Montana’s Confederated Salish and Kootenai Tribes. Cahoon made two bows of the same traditional design from different woods: hickory and vine maple. Petersen directed his students to measure the bending moduli of the bows by hanging weights of various sizes from the bows’ strings. Shooting arrows from the bows will come later—presumably as a reward.

Twin fireballs could have come from a small comet

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SPACE.com: Comets shed material along their orbits. When Earth’s orbit takes our planet through those debris-strewn paths, terrestrial observers see meteor showers in the night sky. On 16 October, automatic sky-watching cameras captured two meteorlike fireballs streaking across the sky. No big meteor showers usually occur on that day, so it came as a surprise that an analysis of the fireballs’ trajectory pointed suggestively to comet Hartley 2 as the source. Unlike comet Tempel-Tuttle, which spawns the famous Leonid meteor shower in November, comet Hartley 2 is thought to be too small to beget meteors. The case remains open.

A device for recording dreams could be possible, a researcher claims

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BBC: In a paper in the latest issue of Nature, Caltech’s Moran Cerf and his collaborators report experiments that directly probed how our imaginations can shape, and even override, what our senses tell us. Cerf’s team looked at the output from detectors attached to single neurons in the brains of 12 epilepsy patients. The patients were shown hybrid images of actors Josh Brolin and Marilyn Monroe and asked to “see” one or the other—that is, to mentally change what was before their eyes. Having already determined which neurons hold either image, Cerf and his team could tell that the patients could reliably override the hybrid image and “see” the image of the requested actor. According to Cerf, his findings suggest that it might be possible one day to record people’s dreams.

Hubble’s costly successor is squeezing other mission budgets

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Nature: To justify its existence, NASA’s next big space-based optical observatory, the James Webb Space Telescope, must significantly outperform its predecessor, the Hubble Space Telescope. Great leaps forward in performance are not cheap. From its perch at the second Lagrangian point 1.5 million km from Earth, JWST will observe young distant galaxies with a mirror that is three times wider than Hubble‘s and with detectors that must be kept no warmer than 50 degrees above absolute zero. Launch is scheduled for 2014. Before then, NASA’s engineers and scientists are conducting extensive tests and reviews to ensure that the expensive telescope will work as planned. And, as Nature‘s Lee Billings reports, JWST‘s price tag, which stands at $5 billion, is so great that it’s starving or delaying other missions.

Graphene’s peerless properties will take time to pay off

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Washington Post: This year’s physics Nobel went to Andre Geim and Konstantin Novoselov for discovering in 2004 how to make graphene, a two-dimensional form of carbon. The discovery excited physicists and engineers because of graphene’s superb electrical and mechanical properties. Writing in the Washington Post, Brian Palmer examines when those properties will prove profitable. The main source of delay lies in finding a way to make the material cheaply and in large batches. Palmer concludes:

As chic as graphene is today, it’s still really a material of the future. But there’s so much money and excitement in graphene research, the future may be soon.

Panel endorses funding extention for Fermilab’s Tevatron

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Physics World: At its meeting yesterday, the High Energy Physics Advisory Panel (HEPAP) recommended that the US Department of Energy should fund a plan to extend the lifetime of Fermilab’s Tevatron proton–antiproton collider. The plan, devised by Fermilab’s director Pier Oddone, calls for an additional $35 million a year to fund the operation of the collider through 2014. In making its recommendation, the panel had to weigh the loss of funding to other particle physics experiments against the advantage of the Tevatron possibly detecting the Higgs boson ahead of its rival, the Large Hadron Collider.