Is dark matter mystery about to be solved?
By Stuart Clark As far as most of the universe is concerned, you’re inconsequential. The everyday stuff that constitutes you and everything you care about makes up just 4 per cent of the cosmos; the rest we call dark matter and dark energy. What they actually are, though, is anyone’s guess. Now we may be on the verge of enlightenment. In this article, we report how experiments are getting ready to identify dark matter, while on page 32 we consider why dark energy may be an illusion created by our place in space. Be prepared for a new cosmic order… THIS YEAR, there’s a good chance that a sizeable chunk of our universe will turn up. A fair bit of the cosmos – 22 per cent of it, in fact – seems to be made of invisible dark matter, whose extra gravity helps to bind stars together in galaxies, and galaxies together in clusters. While we have seen dark matter’s effects in space, no one has actually detected a particle of the stuff. All that may be about to change, however. For decades, researchers have been planning and building experiments sensitive enough to capture fragments of dark matter. According to our best cosmological theories, dark matter is made of hypothetical particles called WIMPs (weakly interacting massive particles). Now the detectors are ready for action and WIMPs are finally within our grasp. So is it time to put the champagne on ice? Well, not so fast. Catching WIMPs is all well and good, but whether they actually turn out to be dark matter is another question. If the new experiments see nothing,