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Adele Wallpapers
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The Best Top Desktop Naruto Shippuden Wallpapers in all kind of resolutions and sizes. For your PC, Windows XP, Windows Vista,...More
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The Best Top Desktop Anime Girls Wallpapers in all kind of resolutions and sizes. For your PC, Windows XP, Windows Vista,...More
Monday, December 27, 2010
3d Wallpapers, Free 3d Wallpapers for Desktop Background
3d Wallpaper for Desktop3d Wallpaper GirlDesktop 3d Wallpaper FreeFree 3d Desktop BackgroundDesktop 3d Wallpaper3d Desktop Free wallpaperWednesday, December 22, 2010
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Number of stars grossly underestimated
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Starry, starry, starry night: Star count may triple
The universe may glitter with far more stars than even Carl Sagan imagined when he rhapsodized about billions upon billions. A new study suggests there are a mind-blowing 300 sextillion of them, or three times as many as scientists previously calculated. That is a 3 followed by 23 zeros. Or 3 trillion times 100 billion.
The estimate, contained in a study published online Wednesday in the journal Nature, is based on findings that there are many more red dwarf stars — the most common star in the universe — than once thought.
But the research goes deeper than that. The study by Yale University astronomer Pieter van Dokkum and Harvard astrophysicist Charlie Conroy questions a key assumption that astronomers often use: that most galaxies have the same properties as our Milky Way. And that conclusion is deeply unsettling to astronomers who want a more orderly cosmos.
When scientists previously estimated the total number of stars, they assumed that all galaxies had the same ratio of dwarf stars as the Milky Way, which is spiral-shaped. Much of our understanding of the universe is based on observations made inside our own galaxy and then extrapolated to other galaxies.
But about one-third of the galaxies in the universe are elliptical, not spiral, and van Dokkum found they aren't really made up the same way as ours.
Using the Keck telescope in Hawaii, van Dokkum and a colleague gazed into eight distant, elliptical galaxies and looked at their hard-to-differentiate light signatures. The scientists calculated that elliptical galaxies have more red dwarf stars than predicted. A lot more.
"We're seeing 10 or 20 times more stars than we expected," van Dokkum said.
Generally scientists believe there are 100 billion to a trillion galaxies in the universe. And each galaxy — the Milky Way included — was thought to have 100 billion to a trillion stars. Sagan, the Cornell University scientist and best-selling author who was often impersonated by comedians as saying "billions and billions," usually said there were 100 billion galaxies, each with 100 billion stars.
Van Dokkum's work takes these numbers and adjusts them. That's because some of those galaxies — the elliptical ones, which account for about a third of all galaxies — have as many as 1 trillion to 10 trillion stars, not a measly 100 billion. When van Dokkum and Conroy crunched the incredibly big numbers, they found that it tripled the estimate of stars in the universe from 100 sextillion to 300 sextillion.
That's a huge number to grasp, even for astronomers who are used to dealing in light years and trillions, Conroy said.
"It's fun because it gets you thinking about these large numbers," Conroy said. Conroy looked up how many cells are in the average human body — 50 trillion or so — and multiplied that by the 6 billion people on Earth. And he came up with about 300 sextillion.
So the number of stars in the universe "is equal to all the cells in the humans on Earth ” a kind of funny coincidence," Conroy said.
For the past month, astronomers have been buzzing about van Dokkum's findings, and many aren't too happy about them, said astronomer Richard Ellis of the California Institute of Technology. Read full story
Tuesday, November 30, 2010
Thunderstorm approaches Bill Snyder
Thunderstorm approaches Bill Snyder
A thunderstorm approaches Bill Snyder Family Stadium during the first quarter of an NCAA college football game between Central Florida and Kansas State Saturday, Sept. 25, 2010 in Manhattan, Kan. Play was suspended in the game due to lightning.
Storm develops over skies of Bangkok on eve
Storm develops over skies of Bangkok on eve
A storm develops over the skies of Bangkok on the eve of May 23, 2010.
Eye of Hurricane Earl is seen
Eye of Hurricane Earl
The eye of Hurricane Earl is seen in this photo taken from the International Space Station August 30, 2010.
Storm clouds carrying heavy rain
Storm clouds carrying heavy rain move afternoon
Storm clouds carrying heavy rain move across downtown Phoenix, Tuesday afternoon, Oct. 5, 2010. A series of powerful thunderstorms hit the area with high winds, hail and heavy rain.
Grave markers are silhouetted
Grave markers are silhouetted by the a swirling cloud of a severe thunderstorm as it passes over a rural cemetery near Wellsville, Kan. Saturday, June 20, 2009. The cell had earlier produced a small tornado but caused no damage.
Storm clouds create dramatic sight
Huge tornado funnel cloud touches down
A huge tornado funnel cloud touches down in Orchard, Iowa, Tuesday, June 10, 2008 at 9:04 p.m. The Globe Gazette and Mitchell County Press News reported that Lori Mehmen of Orchard, took the photo from outside her front door. Mehmen said the funnel cloud came near the ground and then went back up into the clouds. Besides tree and crop damage, no human injuries were reported.
Wednesday, November 17, 2010
6 Best Nature Desktop Wallpapers Free for Desktop Background
Best Free Nature Desktop wallpapers ( Winter Nature Wallpaper ) 6 Free For your Desktop background.
Mountain Desktop Backgrounds for computer
Beautiful Desktop Wallpaper
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Mountain Desktop Backgrounds for computer
Beautiful Desktop WallpaperThursday, November 11, 2010
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