Instead of contracting to a Big Crunch, the universe may actually keep on expanding forever at a faster and faster rate. Now astronomers believe they have confirmed that this universal expansion is accelerating.
An international team of researchers used the Hubble Telescope to chart almost half a million galaxies and map out the spread of dark matter over the history of the universe. Their results not only confirm Einstein's general relativity - which is always nice - but they also appear to prove the existence of dark energy.
University of British Columbia astronomer and team member Ludovic Van Waerbeke explains:
Our results confirmed that there is an unknown source of energy in the universe which is causing the cosmic expansion to speed up, stretching the dark matter further apart exactly as predicted by Einstein's theory. The data from our study are consistent with these predictions and show no deviation from Einstein's theories.
General relativity holds that the universe's structure is entirely determined by its matter, so if the universe is increasingly expanding there has to be something out there that's causing the acceleration. Current theories argue for the existence of three main constituents of the universe - normal matter, dark matter, and dark energy, the "unknown source of energy" to which Van Waerbeke refers. Although this is not the first study to demonstrate that dark energy really is more than a theory, this is by far the most compelling proof yet that the universe's expansion is actually accelerating.