Despite massive resources and expertise that has gone into the Large Underground Xenon Experiment (LUX) so far, scientists have come up empty in their attempts to use it to discern the tell-tale oscillations of dark matter. On Wednesday, October 30, 2013, the lead physicists announced that the mile-deep tank of liquid xenon failed to deliver the expected results – although this hardly represents the end of the operation.
Along with dark energy, dark matter makes up the overwhelming majority of the objects in our universe; and yet, we have little idea what they are. All the stars, planets, galaxies and gases we see (including the atoms and other baryonic particles we don’t see) make up just over four percent of all the mass. All the rest – all 96 percent – is attributable to dark energy and dark matter; whatever these are, they do not interact with light, so we cannot see them.
This is where the 370 kg-of-xenon tank called the LUX detector comes in: it was built nearly five thousand feet underground at the Sanford Underground Research Facility in South Dakota to hopefully find evidence one of the leading candidates for dark matter, called Weakly Interacting Massive Particles (WIMPS). To this end, the Large Underground Xenon Detector
Richard Gaitskell of Brown University, who is a lead collaborator of the hundred or so scientists working on the LUX experiment worldwide, remains optimistic about the detector’s chances. “This is just the opening salvo.” It has only been a few months since the current experiment to detect dark matter was underway, so there seems to be some cause for optimism. “The short story is that we didn’t see dark matter interacting, but we had the most sensitive search for dark matter ever performed in the world,” agreed Daniel McKinsey of Yale University.
The sheer scope and sophistication of the Large Underground Xenon Experiment holds promise that it will someday tell us why one-quarter of the known universe is comprised of mass that doesn’t interact with photons – or at least what it is that’s so resistant to luminosity. Dark matter could be WIMPS, or it could be primordial black holes; LUX is the current hope for finding out. At the very least, it could tell us that the instruments we’re currently using, however powerful they are, just aren’t yet powerful enough.