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Science notes / Astronomy, anthropology

Making the stars swirl

On NASA's Fragile Oasis blog (www.fragileoasis.org), astronauts from the United States and around the world have a forum to share their experiences, including descriptions of what it's like to grow vegetables in zero gravity, meditations on space travel and snapshots from out of this world. Recently, astronaut Don Pettit, a chemical engineer and all-around science expert aboard the international space station, posted about his pet project of taking arty photographs from low Earth orbit.

While the space station spins around the planet, it's also revolving on its own axis, meaning that if you use a long exposure, you get pretty trippy results. In Pettit's photos, the stars have swirling light trails, the atmosphere glows green and the electric lights given off by cities shimmer beneath the clouds. It took a little bit of ingenuity, though.

To get the effect, Pettit needed a 15-minute exposure, which his digital camera couldn't accommodate. "To achieve the longer exposures, I do what many amateur astronomers do," he writes. "I take multiple 30-second exposures, then 'stack' them using imaging software, thus producing the longer exposure."

-- Washington Post

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Evolutionary gift of gab

Fifty thousand years ago, our ancestors were competing with several hominid species. Now we're the last man standing. So, what makes us so special?

In his new book, "Masters of the Planet," Ian Tattersall, an anthropologist and curator emeritus at the American Museum of Natural History, attempts to explain what factors allowed Homo sapiens to consign our less-fortunate cousins to the dusty confines of the fossil record.

It was a combination of elements, really, that eventually added up to the modern human body and mind. Walking upright was critical, he says, because, among other advantages, it helped our ancestors keep cool by exposing more body area to wind and less to the rays of the sun.

But the development of language was the turning point. According to Tattersall, even though other hominid species couldn't talk, they could lead relatively complex lifestyles. Once it finally awakened, our ability to manipulate symbolic information gave us the edge. "Our symbolic abilities explain our possession of reason, while intuition, which is itself probably a curious amalgam of the rational and the emotional, accounts for our creativity," he writes. "It is the fortuitous combination of the two that makes us the unstoppable if imperfect force of nature that we are."

-- Washington Post