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Saturday, February 21, 2009

Discoveries

Chimpanzee See, Chimpanzee Do

A new study suggests that humans aren't the only primates susceptible to peer pressure. Turns out, chimpanzees are clever conformists, too. Not only do they use sticks as tools, they also stick to the tools their peers prefer. So says Professor Andrew Whiten of St. Andrews University, whose team has been working with chimps at Emory University's Yerkes Primate Center in Atlanta, Georgia.

Many scientists have long suspected that chimpanzees maintain what amount to "cultural traditions," which are passed down within specific social groups. To test that hypothesis, Professor Whiten and his team removed two high-ranking female chimps, Erika and Georgia, from their respective peer groups. They then taught each a different technique for getting grapes from a complex contraption. Erika's technique involved lifting a block with a stick. Georgia's involved pushing a block with a stick.

Each grape-getting gal then got to show off her technique to her peer group. Soon, Erika's group had learned to lift, while Georgia's had learned to push. In time, some chimps stumbled upon grape-getting methods on their own. Notably, some lifters learned to push, a behavior that comes more naturally for chimps. Yet these enterprising primates soon abandoned the techniques they'd found in favor of the ones their peers preferred. Next thing you know, they'll all be wearing the same brand of worn-out blue jeans.

Explore chimpanzee culture for yourself

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Laser Guns Get Real (Sort Of)

Think laser guns are the stuff of science fiction? Think again. The U.S. Defense Advanced Research Projects Agency (DARPA) has designed a weapons system that could make tomorrow's fighter pilots feel like Luke Skywalker. The High Energy Liquid Laser Area Defense System (HELLADS) is small enough to mount beneath a fighter's wing, yet powerful enough to blast a missile out of midair. The folks at DARPA aren't exactly ready for a run-in with Darth Vader, but they do have a working prototype built.

Previously, laser systems powerful enough to shoot down missiles have all been too big for aircraft smaller than jumbo jets to carry. So what makes this system different? Details of the design are top secret, but according to New Scientist magazine, it involves "a hybrid of two different types of laser, liquid and solid state." Solid state lasers pack plenty of punch, but they have to be fired in pulses to keep from overheating. Liquid lasers can fire continuously--as long as you've got a large enough cooling system.

The HELLADS weapon is designed to maximize punching power while minimizing cooling requirements. The final system should be about the size of a refrigerator and weigh around 1,650 pounds (750 kg), cooling system and all. The existing prototype fires a 1-kilowatt beam. The real weapon will have to fire a 150-kilowatt one. That means the folks at DARPA have a good ways still to go, but not quite the distance between fiction and fact.

Learn how lasers work


"If I have ever made any valuable discoveries, it has been due more to patient attention than to any other talent."
--Isaac Newton


Sight of the Week:
The Sparkle of Venetian Art

For centuries, fans of Renaissance art have marveled at the colors captured by 16th-century Venetian painters like Titian and Tintoretto. Now experts have discovered one of the secrets of the Venetians' sparkle. Using an electron microscope, Barbara Berrie of the U.S. National Gallery of Art examined paint samples from 16th-century Venetian works. Some of the paints the Venetians used, she found, contained powdered glass.

Evidently, the Venetian masters were on the cutting edge of pigment experimentation in their day--and may have swapped trade secrets with Venice's famous glassmakers. In honor of their respective explorations, this week we're rediscovering colorful Venetian masters at Barbara Berrie's home base, the National Gallery of Art.

Take a Titian tour

See Venetian paintings of the later 16th century

Steve Sampson
August 26, 2005

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