Eat Up: Eating a large meal at the holidays won't have a big impact on your weight, says one physiologist. That's because your brain keeps a close watch on food intake and can tolerate the occasional big meal. It's slow, steady weight gain that's more problematic. hide caption

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City of Miami police officer E. Dominguez conducts a field sobriety test in 2007. One approach to reducing traffic deaths that's common in Europe is frequent roadside sobriety checks, says Adrian Lund, president of the Insurance Institute for Highway Safety. Joe Raedle/Getty Images hide caption

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A fruit fly larva's body is covered with a network of photosensing neurons that help it detect and avoid light. The cells glow under a light with the help of a green fluorescent protein. Dr. Chun Han/University of California, San Francisco hide caption

itoggle caption Dr. Chun Han/University of California, San Francisco

Scientists at Stanford argue that the same genes responsible for immunity in chimps may also be the reason humans have such big brains. Above, a young chimpanzee at Sydney's Taronga Zoo. Mark Kolbe/Getty Images hide caption

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Virgin Galactic is developing a suborbital spacecraft to carry spaceflight participants to about 65 miles above Earth. The craft, SpaceShipOne, is carried high above the Earth by a special plane called The White Knight, then launched. Courtesy of Scaled Composites hide caption

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Bates and his research team used pingpong balls and red pipe cleaners to model the "hairy spherical block copolymer particles." The actual spheres are roughly 1 million times smaller, and each contains about 200 polymer molecules, represented by the red pipe cleaners. Courtesy of Frank Bates hide caption

itoggle caption Courtesy of Frank Bates

A dwarf minke whale swims near the Great Barrier Reef. Scientists say whale dung can help feed hungry fish near the surface of the ocean. Kike Calvo/AP hide caption

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A National Science Foundation artist's drawing shows the inner four planets orbiting Gliese 581, a red dwarf star just 20 light-years from Earth. The newly discovered planet, in the foreground, has a 37-day orbit and, like Earth, is distant enough from the star for liquid water to exist. Lynette Cook hide caption

itoggle caption Lynette Cook

Albert Einstein's theory of relativity challenges how we perceive time in our everyday lives. Now, researchers have a device precise and accurate enough to measure its effects in the laboratory. Keystone/Hulton Archive/Getty Images hide caption

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Basking sharks have been added to the "species of concern" list, and scientists hope to learn more about how the giant fish behaves in Pacific waters. Gregory B. Skomal/NOAA hide caption

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