Cosmic camera trains lens on dark energy

摘要

The biggest camera ever put into space could solve what has become the most important problem in cosmology: the nature of the mysterious dark energy which appears to be speeding up the Universe's expansion. It will do this by measuring the brightness and distance of 2000 supernovae, helping determine which model of dark energy seems most accurate. The concept of dark energy emerged in 1998, when it was discovered that distant supernovae of known brightness were fainter than expected. The favoured explanation for this is that the expansion rate of the Universe must have increased since the supernovae exploded, pushing them farther away and so making them fainter. If this is so, some previously unseen force must be driving the galaxies, and this force is associated with something dubbed dark energy.