TOP 100 CAMPING SITES
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| Bye-bye birdies: 2 percent of world's bird species "critically endangered" More bird species than ever face extinction, though conservation efforts are, in some cases, slowing the pace of the decline. [More] rss.sciam.com |
Supreme Court Said to Stymie Environmental Causes Environmental interests were trounced in the 2009 Supreme Court term that ends Monday. [More] rss.sciam.com |
First U.S. "Power Tower" Lights Up California In southern California's Antelope Valley, 24,000 silver-bright mirrors have been positioned to reflect light on two 50-meter-tall towers. And at 11:08 A.M. local time Wednesday, this concentrated light heated steam in those towers to turn a turbine--the first " power towers " in the U.S. to convert the sun's heat into electricity for commercial use.Dubbed Sierra SunTower, the power plant can produce five megawatts, enough to power roughly 4,000 local homes at full capacity--and provide the modular blueprint for larger plants in California and New Mexico, according to eSolar , the Pasadena start-up behind the power plant. [More] rss.sciam.com |
How Quantum Effects Could Create Black Stars, Not Holes (preview) Black holes have been a part of popular culture for decades now, most recently playing a central role in the plot of this year’s Star Trek movie. No wonder. These dark remnants of collapsed stars seem almost designed to play on some of our primal fears: a black hole harbors unfathomable mystery behind the curtain that is its “event horizon,” admits of no escape for anyone or anything that falls within, and irretrievably destroys all it ingests.To theoretical physicists, black holes are a class of solutions of the Einstein field equations, which are at the heart of his theory of general relativity. The theory describes how all matter and energy distort spacetime as if it were made of elastic and how the resulting curvature of spacetime controls the motion of the matter and energy, producing the force we know as gravity. These equations unambiguously predict that there can be regions of spacetime from which no signal can reach distant observers. These regions--black holes--consist of a location where matter densities approach infinity (a “singularity”) surrounded by an empty zone of extreme gravitation from which nothing, not even light, can escape. A conceptual boundary, the event horizon, separates the zone of intense gravitation from the rest of spacetime. In the simplest case, the event horizon is a sphere--just six kilometers in diameter for a black hole of the sun’s mass. [More] rss.sciam.com |
Newspapers Worldwide Call For Climate Change Action It’s like the publishing version of one of those scenes from a sci-fi movie where an alien invasion impels traditional adversaries to join together to face their larger, common threat. Today 56 newspapers, in Pakistan and India, in Israel and Lebanon, in Tawian and China, in Greece and Turkey, in Africa and in North, South and Central America are publishing an unprecedented joint editorial calling for meaningful action to face the threat posed by climate change. The editorial, published in 45 countries in 20 different languages, appears on this first day of the Copenhagen climate conference. The British paper the Guardian led the effort, which involved weeks of negotiations to reach a final version.The editorial notes that “the science is complex but the facts are clear. The world needs to take steps to limit temperature rises to 2 degrees C...a bigger rise of 3 to 4 degrees C would parch continents, turning farmland into desert. Half of all species could become extinct, untold millions of people would be displaced, whole nations drowned by the sea. The controversy over emails by British researchers that suggest they tried to suppress inconvenient data has muddied the waters but failed to dent the mass of evidence on which these predictions are based.” [More] rss.sciam.com |