Random Samples

Science  19 Nov 2004:
Vol. 306, Issue 5700, pp. 1286
  1. Riding on Air


    Just as powdery snow supports a slaloming snowboarder, a material as fluffy as goose down may be able to support a speeding train, a team of biomedical engineers has calculated.

    Sheldon Weinbaum of City College of New York and colleagues arrived at this provocative idea from studying blood flow. Blood vessels are lined with a compressible gel, and red blood cells glide over it by surfing the liquid trapped in the gel. In the same way, the scientists calculated, a sliding snowboarder rides the air trapped in fresh snow and not the snow itself. They squeezed snow in a piston and found that it held air long enough to support a snowboarder moving at 10 meters per second, they report in the 5 November Physical Review Letters.

    The scientists then tried squeezing goose down. It didn't hold air as well as snow did, but it still sustained a sizable pressure surge for a couple tenths of a second. Scaling up from the data, the researchers argue that when spread in a channel with airtight sides, a material like goose down could support a 25-meter-long, 50-metric-ton train car moving at least 70 kilometers per hour. Weinbaum hopes to build a working scale model of the tobogganing tram.

    “It's surprising that such great loads can be supported by just air and a porous medium,” says Timothy Pedley, a fluid dynamicist at the University of Cambridge in the United Kingdom. But spiriting trains along fluffy byways is so far just a wild idea.

  2. Next New Jersey Stamp?


    It's a little-known fact, but every state has a “state soil,” according to the U.S. Department of Agriculture. And state lawmakers are increasingly making their soils official. In New Jersey last week, for example, the agriculture committee of the state assembly unanimously voted to elevate the status of its Downer soil, a grayish sandy loam good for growing forests that predominates on the state's southern coastal plain. And why not? As David Friedman, director of Ocean County's soil conservation agency, told a New York radio station: “Earth's carpet is the soul of food consumed by livestock and mankind.”

  3. What, Not How

    Discovery learning—the idea that children learn better if they “construct” new knowledge on their own—is big in pre- college science and math education. But psychologist David Klahr of Carnegie Mellon University in Pittsburgh, Pennsylvania, says there's nothing special about it; it's simply less efficient than having a teacher.

    Klahr led a study in which 112 third- and fourth-graders were told to design experiments involving a ball and a ramp. Half were told how to design valid experiments; the others were left on their own. Not surprisingly, 77% of the instructed group—but only 23% of the discovery group—got most of the experiments right, according to a report in the November issue of Psychological Science.

    More telling was the result of the next task, which was to critique two flawed sixth-grade science fair posters. Again, those in the direct-instruction group performed far better than the others, showing that they were able to transfer their new knowledge of the scientific method to other subjects— in this case, the effect of holes on a Ping-Pong ball and sex differences in short-term memory.

    Klahr says the research shows that “once you've mastered something, it doesn't matter how you got there” and belies the notion that “if kids haven't participated in creating knowledge on their own, it's going to be very brittle, and it won't transfer.” Education professor Richard Shavelson of Stanford University notes that the “discovery” condition in this study “was far more laissez-faire” than would be found in most classrooms. Nonetheless, he says, “we need more of this hard-nosed research.”

  4. Tracking Ocean Wanderers


    And the good south wind still blew behind, But no sweet bird did follow …

    Samuel Taylor Coleridge, The Rime of the Ancient Mariner

    Albatrosses have a lot more to worry about these days than being shot by sailors. More than 100,000 each year are accidentally hooked by longlines set for tuna, billfish, and Patagonian toothfish, pushing some albatross species to the brink of extinction (Science, 2 April, p. 44). Now a new report has meticulously collated scores of satellite tracking studies and identified hot spots where petrels and albatrosses may cross paths with fisherfolk.

    Tracking Ocean Wanderers, published by BirdLife International, was unveiled last week at a conservation meeting in Hobart, Australia. John Croxall of the British Antarctic Survey in Cambridge, U.K., who edited the report, says he hopes it will convince fisheries managers who still deny there's a problem. Ben Sullivan, coordinator of BirdLife's Global Seabird Programme, says the maps will allow conservation efforts to be better targeted, identifying times of year when certain longline fisheries should be closed and areas where mitigation measures, such as weighted lines and bird-scaring streamers, should be used.

  5. Awards


    In mother's name. French embryologist Nicole Le Douarin is the inaugural winner of the $50,000 Pearl Meister Greengard Prize, an award for women scientists founded by Nobelist Paul Greengard.

    Greengard, a professor at Rockefeller University in New York City, used his one-third share of the 2000 Nobel Prize in physiology to set up an endowment for the award, named after his mother, who died giving birth to him. “Women have made enormous strides in science, but they are not yet receiving awards and honors at a level commensurate with their achievements,” he says.

    Le Douarin, a researcher at the College of France in Paris, studies cell development in bird embryos.

  6. Misfortunes

    Data deluged. A Halloween storm that dumped 25 cm of rain on Manoa in 24 hours has washed away a big part of University of Hawaii geneticist Terrence Lyttle's lifework.

    Lyttle, 56, was inside the lab when the nearby Manoa Stream overflowed, flooding several labs on campus as well as other portions of town. It was all Lyttle could do to grab his dog and flee the building. One-third of the fruit flies that Lyttle uses in his population genetics studies drowned in the flood.

    Lyttle has moved to another lab, and he hopes to use any insurance money to hire new postdocs. But the fate of his research program is uncertain. “The prospect of trying to put things back together is rather daunting,” he says.

  7. Deaths

    Weapon of conscience. Theoretical physicist Theodore Taylor, who spent his early career designing atomic bombs and later campaigned for the abolition of nuclear weapons, died in Silver Spring, Maryland, on 28 October. He was 79.

    Taylor helped design miniature fission weapons at Los Alamos National Laboratory in the 1950s. But his views changed during 2 years at the Defense Atomic Support Agency, an intellectual about-face immortalized in John McPhee's 1974 book-length profile, The Curve of Binding Energy.

  8. Explorers


    Dead on. Adam Striegel plans to be an elementary school teacher. But, along the way, the college senior has made an important scientific discovery.

    Striegel was on a field trip this spring for an introductory geology course at the University of Pittsburgh, Pennsylvania, when he made the find of a lifetime: the skull of a 300-million-year-old amphibian. He and his instructor, geologist Charles Jones, took the softball-sized fossil to David Berman, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh, who has identified it as a trematopid amphibian, a landlubber previously known from only two specimens of that age. “The skull is almost perfectly preserved three dimensionally,” says Berman. Striegel (pictured here with museum's Amy Henrici) has donated the fossil to the museum, and Berman intends to name it after him and provide a cast as a keepsake.

    Striegel plans to keep the cast on his desk as a learning tool for his future students. “I don't think I'll have any problem getting them interested in that part of science,” he says.

  9. Pioneers

    Catch them young. Cancer biologist Frances Balkwill began a parallel life as an author of children's books to explain her research to her two children. Fourteen years and 13 books later, her literary endeavors on topics from DNA to microbes have earned her a $6500 communication award from the European Molecular Biology Organization.

    You, Me, and HIV is the latest offering from Balkwill, who directs the Cancer Research UK Translational Oncology Center in London. More than 100,000 copies of the book, illustrated by Mic Rolph, are being distributed in Africa to combat the AIDS epidemic.

    The challenge in writing for children, Balkwill says, is “to think right down to the nub of the matter” and keep things simple without being patronizing. It helps to use “the minimum of words and the maximum of pictures,” she adds. Don't shy away from big words like “deoxyribonucleic acid,” she advises, but do spell them out phonetically.

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