May 20, 2011 Leave a comment
Einstein was right all along: the future is dark
May 20, 2011
IT’S official. The universe is slowly fading away into the distance. An invisible force thought to be pushing the cosmos ever faster apart does exist, Australian astronomers have concluded.
The team is the first to have looked at the structure of the universe more than halfway back in time, to a period when this repulsive force, known as dark energy, began to dominate over the pull of gravity.
Chris Blake, of Swinburne University, said the results of their four-year survey of more than 200,000 distant galaxies show the mysterious force is a property of space itself.
The possible existence of an all-pervading repulsive force was first revealed in 1998, when two teams, one led by Brian Schmidt of the Australian National University, discovered that the expansion of the universe was speeding up, rather than slowing down as thought.
The team of 26 astronomers, co-led by Dr Blake, used the Australian Astronomical Observatory near Coonabarabran in NSW to observe the force’s effect on how galaxies were clustered together about 7 billion years ago, more than halfway back to the Big Bang.
Dr Blake said their results support the idea that dark energy is the ”cosmological constant” – a repulsive force Albert Einstein proposed almost a century ago to explain why the universe did not collapse on itself.
The famous scientist later dismissed the idea as ”his greatest blunder”. But he was right after all, Dr Blake said. ”Einstein remains untoppled.”
Dark energy will continue to push galaxies ever faster away until they fade completely from view. It might also result in a ”Big Rip”, as matter is torn apart, atom by atom, Dr Blake said.
Two studies, on the distribution of the galaxies and the rate at which clusters formed, are published in the Monthly Notices of the Royal Astronomical Society.