The search for dark matter continues

I wrote last month about recent reports on the failure of two major experiments named LUX and PandaX-II to directly detect dark matter and what that might mean for the prospects of alternate theories to explain anomalous gravitational effects. Of course, concluding that dark matter is non-existent is a tricky call since we don’t really know what it is made of and the negative results so far may well be due to the lack of sufficient sensitivity of the detectors or that dark matter is made of something quite different from what the detectors are designed to register.

On the assumption that dark matter is made of WIMPs (Weakly Interacting Massive Particles), a new, more sensitive, detector known as LUX-Zeplin is being constructed one mile underground, at the same site as the earlier LUX experiment in South Dakota, that will use 10 tons of liquid xenon.

“The detector is set up like an enormous bell capable of ringing in response to the lightest tap from a dark matter particle,” the university explained in the statement. “If a piece of dark matter runs into a xenon atom, the xenon will collide with its neighbors, producing a burst of ultraviolet light and releasing electrons. Moments later, the free electrons will excite the xenon gas at the top of the chamber and release a second, brighter burst of light.”

However, the detector will become operational only in 2020. Science requires a great deal of patience.

Here’s a NASA video from four years ago that discusses the case for WIMP dark matter and what scientists are looking for as a signature of its presence.

For those in the Cleveland area, tonight’s Science Café discussion will feature Stacy McGaugh, chair of the Astronomy department at CWRU, who will discuss the current state of affairs concerning dark matter. These monthly events are free and open to the public.


  1. Rob Grigjanis says

    Marcus @1: Depends how you define “a lot” and “new insights”, I guess. Searches for new particles can mean decades of reducing the parameter space that they could occupy. The top quark was proposed in 1973, discovered in 1995. The Higgs boson was proposed in 1964, discovered in 2012. And the road from proposal to discovery can be a lot of small steps. Always more exciting from the inside than to outside spectators. More like “gosh, we’re finding out more!”.

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