Hugh Pickens writes writes: "Either 75% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or Einstein's General Relativity must be replaced by a new theory of gravity on cosmic scales as Kelsey Campbell-Dollaghan reports that a team of 120 scientists has unveiled the world’s most powerful digital camera, 10 years in the making, that may shed light on dark energy: the 570-megapixel Dark Energy Camera, capable of recording light from galaxies 8 billion light years away. Over the next 525 nights of observation, the camera, containing 74 CCDs constructed specifically to be sensitive to the redshifted light from distant galaxies and stars, will capture a detailed 3-D map over 300 million galaxies as part of a massive international effort to explain the universe’s acceleration, called the Dark Energy Survey. Installed on a hilltop observatory in the Chilean Andes, where atmospheric conditions are ideal, the camera will be studying four types of phenomena: galaxy clusters, supernovae, the large-scale clumping of galaxies, and weak gravitational lensing. Each of those have been studied on their own, but for the first time, scientists will be able to cross-reference each type of element against the others, rendering a more precise understanding of their behaviors. "The results of this survey will bring us closer to understanding the mystery of dark energy (PDF)," says James Siegrist, associate director at the US Department of Energy. "And what it means for the universe.”"