Random Samples

Science  17 Aug 2007:
Vol. 317, Issue 5840, pp. 877
  1. NETWATCH: Opening NASA's Vault

    The moon shots that researchers and the public have gazed at over the years are mainly copies—or copies of copies—that don't match the originals in clarity, color, or contrast.

    But at last, we all will get to see the originals. Arizona State University (ASU) in Tempe, the Lunar and Planetary Institute, and NASA are posting high-resolution scans of the 35,000 photos from the Apollo missions—from film that has been chilling out in a freezer in Houston, Texas, for more than 30 years.

    The digitized images will enable researchers to draft more precise topographic maps of the lunar surface, for example, and to evaluate possible landing sites for future moon missions, says geologist Mark Robinson of ASU. The archive is just gearing up but will have several hundred images by next month.



    Chimp skull showing the distribution of stress during a bite at the second molar. CREDIT: COMPUTATIONAL BIOMECHANICS RESEARCH GROUP, UNIVERSITY OF NSW, AUSTRALIA

    Using finite-element analysis, a computersimulation technique employed in engineering, Australian scientists have put together a super-refined virtual skull that reflects the properties of different types of bone in measuring stresses. Paleontologist Stephen Wroe of the University of New South Wales in Sydney says models such as this chimp skull, based on hundreds of computed tomography scans, can be used for testing applications such as surgical procedures, crash helmets, and dental prosthetics.

    His team also hopes to model skulls of ancient human ancestors to see how their biomechanical features differed and illuminate their dietary leanings and limitations. It's a “novel and useful approach,” says paleoanthropologist Dean Falk of Florida State University in Tallahassee. “I'd love to see what they come up with for Paranthropus”—a heavyset australopithecine believed to have favored plants and grubs.


    Glass of skim milk generated from its optical properties. CREDIT: J. R. FRISVAD ET AL., ACM SIGGRAPH (2007)

    For visual-effects creators, rendering objects like the mist-emitting Pensieve in Harry Potter is no mean feat. Even creating a realistic glass of milk can take computer artists hours of tedious work. But a new image-generating technique may accurately replicate many substances given only the type and amount of their ingredients.

    “If we know what it's made of, we can say what it looks like,” says computer scientist Henrik Jensen of the University of California, San Diego, who outlined the technique last week at a computer-graphics conference in San Diego.

    Jensen, who won a 2004 Academy Award for a novel method of rendering skin that was used to create The Lord of the Rings' Gollum, worked with colleagues from the Technical University of Denmark in Lyngby to broaden a 100-year-old model of optical scattering called Lorenz-Mie theory. The team extended it to include irregularly shaped particles like the constituents of milk, seawater, and other light-absorbing substances.

    The technique can also be run in reverse to derive a substance's composition from digital photographs. Commercially, this could make it possible to spot spoiled or contaminated food. A Danish company, Danisco, is interested in using it to check the freshness of milk and ice cream.



    Archaeologists in Hungary announced this month that they have unearthed a 7-million-year-old forest that has resisted fossilization, the largest of its kind in the world.

    Strip miners stumbled across stumps while digging for coal. Scientists from Eötvös University in Budapest have identified the remains of 16 Taxodium trees, similar to Florida cypress, standing as much as 6 meters tall and 3.5 meters in diameter. They were preserved in a Miocene swamp after sand engulfed them, shielding them from wind, rain, and degrading fungi, says paleontologist Miklós Kázmér.

    The cellulose that makes up the cell walls of the tree has long since broken down, but the remaining lignin has kept the trees standing although very crumbly. Researchers are wrapping the stumps in plastic and submerging them in water to preserve them while they raise money for a costly several-year polymer bath.

    The forest offers a rare “high-resolution photograph from the past,” says Kázmér, who notes that almost all ancient nonfossilized wood so far found has been driftwood. Paleoecologist Christopher Williams of Franklin and Marshall College in Lancaster, Pennsylvania, says scientists can learn a lot from these trees, including the thickness of the canopy and how much carbon they sequestered. Kázmér adds that biologists are eager to collect DNA samples in hopes of finding ancient organisms.