Drew Wilson
March 1st, 2011, 06:28 PM
You've probably never heard of a galaxy known as NGC 6264, and you've surely never given it a whole lot of thought. But the distant star cluster has just provided astronomers with new insight into one of the most mysterious forces in the universe.
To understand that force even a little, think about the last time you threw a baseball straight up in the air. What happened was what will always happen as long as you live on earth: gravity made the ball slow, stop and fall back to the ground. If you were born on the planet Krypton and landed here as a baby, the ball would reach escape velocity and shoot into outer space.
Astronomers trying to understand the history of the universe have long thought of galaxies as huge, shiny baseballs. They were flung outward about 13 billion years ago, in the Big Bang; that's why the universe is expanding. But whether they would someday stop and reverse direction under their mutual gravity or keep going forever wasn't clear. To figure it out, two teams of observers decided more than a decade ago to look deep into the cosmic past, by comparing the velocity of extremely distant galaxies with that of closer ones. The farther you peer into space, the farther you peer back in time, and so if the more remote galaxies are flying apart faster than the close ones, that means the slowdown has already begun. If not, it will probably never happen.
To the astronomers' amazement, they found that the universe is actually expanding faster now than it was billions of years ago. It's as though the baseball had a rocket attached. And the only plausible explanation was that some mysterious, invisible source of energy must be pushing the universe apart faster and faster all the time.
More... (http://www.time.com/time/health/article/0,8599,2055568,00.html#ixzz1FPBgD171)
Dammit! I still want my warp drive!
To understand that force even a little, think about the last time you threw a baseball straight up in the air. What happened was what will always happen as long as you live on earth: gravity made the ball slow, stop and fall back to the ground. If you were born on the planet Krypton and landed here as a baby, the ball would reach escape velocity and shoot into outer space.
Astronomers trying to understand the history of the universe have long thought of galaxies as huge, shiny baseballs. They were flung outward about 13 billion years ago, in the Big Bang; that's why the universe is expanding. But whether they would someday stop and reverse direction under their mutual gravity or keep going forever wasn't clear. To figure it out, two teams of observers decided more than a decade ago to look deep into the cosmic past, by comparing the velocity of extremely distant galaxies with that of closer ones. The farther you peer into space, the farther you peer back in time, and so if the more remote galaxies are flying apart faster than the close ones, that means the slowdown has already begun. If not, it will probably never happen.
To the astronomers' amazement, they found that the universe is actually expanding faster now than it was billions of years ago. It's as though the baseball had a rocket attached. And the only plausible explanation was that some mysterious, invisible source of energy must be pushing the universe apart faster and faster all the time.
More... (http://www.time.com/time/health/article/0,8599,2055568,00.html#ixzz1FPBgD171)
Dammit! I still want my warp drive!