In the News
Beginning this issue, Science Observer presents a brief
roundup of notable recent items about scientific research culled
from news reports. These items are compiled from two free
electronic newsletters produced by Sigma Xi's Public
Understanding of Science program. Science in the News
Daily is e-mailed to subscribers each weekday; Science
in the News Weekly, which reviews the previous week and weekend
in science-related news, is produced in collaboration with
American Scientist Online. To sample the e-newsletters and
sign up, visit www.sigmaxi.org/sitn and www.americanscientist.org/sitnweekly.
Titan Volcano May Be Source of Methane in the Moon's
As much as three percent of the smoggy atmosphere of Saturn's moon
Titan is made up of methane. Having any atmosphere at all makes
Titan unique among moons, but scientists have been particularly
puzzled over the presence of methane. A recent image snapped by the
Cassini spacecraft hints at an answer. The image shows a circular
topographical figure with two wings jutting out from it. The feature
in the image looks much like volcanoes viewed on Earth and Venus, so
the researchers posit that this ring on Titan is a volcano some 19
miles in diameter, and its wings are flows of ice and methane. A
pool below the surface probably supplies the methane.
Sotin, C., et al. Release of volatiles from a possible
cryovolcano from near-infrared imaging of Titan. Nature
435:786-789 (June 9) .
Smells Like Liquid Television: Oxytocin Promotes Human
A nasal spray that washes away protective suspicions sounds too full
of insidious potential to be true, but it's not some villainous
comic book fantasy. Researchers report that the hormone oxytocin
promotes trust among human beings. They extracted the hormone into a
nasal spray, and set up an experiment in which subjects were given
money to invest. Half of the investors were dosed with the oxytocin
spray; half were not. The result: Those exposed were twice as likely
to risk all of their money with strangers, and in the end had
invested 17 percent more of their money than the control subjects.
However, their inhibitions dropped only in face-to-face encounters.
Kosfeld, M. et al. Oxytocin increases trust in
humans, Nature 435:673-676 (June 2).
New Evidence Revives Old Debate over California's Ancient
Did ancient Polynesians visit Southern California between 500 and
700 A.D.? A controversial new study in the journal American
Antiquity suggests that the answer is yes. The paper bases
its conclusions on two strands of theory: Revised carbon dating of
an ancient ceremonial headdress suggests that Southern California's
Chumash Indians were fishing deep-sea waters at about the same time
as the Polynesians, and the Chumash word for "sewn-plank
canoe" is similar to the Polynesian term for redwoods, which
they used to make a similar type of canoe. The contention reawakens
the "transpacific diffusion" hypothesis, which holds that
Pacific Islanders and Asians may have visited ancient North
America—an idea that fell out of anthropological favor in the
Klar, K. A., and T. L. Jones. Diffusionism reconsidered:
linguistic and archaeological evidence for prehistoric
Polynesian contact with Southern California. American
Antiquity 70:457-484 (July).
Readings Released from Sumatran Quake
The marriage of highly sensitive technologies with data on the
devastating energy released by last December's Sumatra-Andaman
earthquake and tsunami has produced a stunning, comprehensive view
of the geological event. Some facts: The event created the longest
fault rupture ever observed, tearing an 800-mile gash in the earth's
crust. The quake also released energy equal to the explosion of 100
billion tons of TNT. All that energy caused oscillations sensed by
seismographs around the world.
Lay, T., et al. The great Sumatran-Andaman earthquake
of 26 December 2004. Science 308:1127-1133 (May
Honeybee's Waggle Dance an Elaborate Communication
Most biologists believe the famed waggle dance of the honeybee
constitutes coded language that directs other bees to nectar and
pollen. The insight won Karl von Frisch a Nobel Prize in 1973. It
also sparked dissent: The dance is just a meaningless paroxysm
brought on by the scent of food, others said. A recent study used
radio transponders to track honeybees and determine flight paths,
then collapsed them into hard data that finally tied the dance to
language. Sure enough, after the bees seemed to confer about sweet
but scent-free sucrose stocked at the far end of an isolated German
meadow, those recruited by the dance-language flew to the source,
even calculating for wind drift.
Riley, J. R., et al. The flight paths of honeybees
recruited by the waggle dance. Nature 435:205-207 (May
Sunlight Trips the Eye Fantastically
"Nothing is as it appears to be." The axiom can be applied
to our perception of the sky, which is influenced by a mix of
atmospheric physics and our own physiology. While passing through
the Earth's atmosphere, sunlight scatters off oxygen and nitrogen
molecules in the air. The light with the shortest wavelengths moves
around the most, so blue abounds. But that's only half the story.
Other colors are there, too—at least as much violet light, in
fact, as blue. So why is the sky blue and not purple? Each time we
look up at the sky, the spectrum of colors represented tweaks the
circuitry inside our eyes, causing us to detect instead a mixture of
pure white light and pure blue.
Smith, G. Human color vision and the unsaturated blue color of
the daytime sky. American Journal of Physics 73:590-597 (July).