Universe expansion may be slowing, not accelerating, study suggests

Astronomers cast doubt on Nobel prize-winning theory and suggest universe could end in big crunch'

Astronomers have cast doubt on a Nobel prize-winning theory that the expansion of the universe is accelerating, suggesting that instead it may be slowing down.

If confirmed, this would have profound implications for the fate of the universe, raising the possibility that rather than expanding for ever, the universe could ultimately enter a reverse big bang scenario known as the big crunch. The astronomers behind the work say their observations also imply that dark energy - the mysterious force thought to be propelling the expansion of the universe - is weakening over time.