THE world's most powerful telescopes are being turned on distant supernovae to close in on dark energy, the mysterious stuff that is thought to be pulling the universe apart. And the results so far suggest that dark energy resembles the "cosmological constant", which Einstein proposed before anyone even knew that the universe was expanding.
Astronomers first discovered dark energy in the 1990s, while studying type 1a supernovae - exploding stars that act as useful markers for time and distance in the universe. It's known that these supernovae always shine with about the same peak brightness, so by measuring how bright one appears from Earth, you can work out how far away it was and how much time has passed since the star exploded.
Because the supernova's light has travelled through an expanding universe, its wavelength has stretched and shifted towards the red end of the spectrum - so the greater ...
Subscribe today at only USD $5.95 for your first 4 issues and get New Scientist, the world's leading science & technology news magazine delivered direct to your door every week
As a magazine subscriber you will benefit from instant access to:
