A Darkness on the Edge of the Universe

It hasn't made front pages yet, and it has little to do with "business innovation powered by technology," but an astronomer at Johns Hopkins University has provided the strongest evidence yet that our universe is pervaded by invisible dark matter. It's a discovery that could at once confirm the Einsteinian view of the fundamental laws of gravity, and re-shape our basic thinking about the cosmos.Briefly, astronomer James Jee used a series of images from the Hubble Space Telescope, and a set of inferences based on "gravitational lensing" (the fact that light is distorted by the gravity of massive objects), to map a giant cluster of galaxies five billion light years from Earth. The resulting map shows how mass is distributed across the cluster. That distribution can only be explained, says Jee, by the presence of a vast ring of invisible stuff - dark matter -- surrounding the cluster. The ring of dark matter was most likely formed when the cluster collided with another group of galaxies eons ago.

"The collision between the two galaxy clusters created a ripple of dark matter that left distinct footprints in the shapes of the background galaxies," explained Jee.

It's a bit like inferring the presence of a big rock at the bottom of a pond by detecting the ripples formed on the surface when the rock plunged into the pond years ago. Other astronomers have greeted the news with skepticism - but the technique used by Jee can almost certainly be applied to other huge galaxy clusters, and it may well lead to a convincing body of evidence that the stuff we can actually see makes up only a fraction of what's actually out there in deep space.