Posted by Scott Ellis (206.168.33.195) on February 10, 2003 at 15:58:54:
http://www.smh.com.au/articles/2003/02/10/1044725732451.html
excerpt:
NASA is expected to announce this week that it has proved the existence of "dark energy", a cosmic force that counteracts gravity and will keep the universe expanding forever. The announcement will effectively demolish the theory that life will be wiped out in a "big crunch" when the universe collapses, and should end decades of academic dispute.
Scientists ranging from Stephen Hawking, the Cambridge University physicist, to Albert Einstein, have argued that the universe eventually will stop expanding and then implode under the force of gravity, destroying all life.
NASA's research indicates, however, that this analysis is wrong. Using a satellite - the Microwave Anisotropy Probe - which has spent the past year peering into deep space, NASA has found a pattern of "hot spots" which proves that the expansion of the universe is accelerating.
This means that "dark energy" - the only force that could cause this acceleration - exists, and that the universe is expanding too quickly to collapse under gravity, ruling out the possibility of a "big crunch".
Anthony Lasenby, an astrophysicist at Cambridge University, said the announcement would transform our view of the universe.
Another scientist explained: "It is like throwing a ball in the air. If gravity were the only force at work, the ball would slow down and then start to fall back. What this shows is that the ball is not slowing down but is in fact accelerating away."
The NASA discovery is understood to be one of the most significant in cosmology. The behaviour of the universe is a subject that has troubled some of the greatest minds in science.
In 1917, to balance the equations in his general theory of relativity, Einstein argued that an unknown force - which he labelled the "cosmological constant" - was counteracting gravity and keeping the universe a constant size. In the wake of subsequent astronomical evidence that the universe was expanding, however, he abandoned this idea, calling it his greatest mistake.
The new data will show that Einstein's attempt to fiddle his equations using this "cosmological constant" may have been right, albeit for the wrong reasons.