The LUX experiment in a South Dakota gold mine has reached an exciting new phase in its hunt for dark matter. We checked in with Richard Gaitskell, the lead researcher on the project. Highlights from that conversation:
What is dark matter?
"Dark matter is the label we use for most of the mass in the universe. It's a rather surprising admission, but ... we still we still don't know what most of matter in the universe is. ... Dark matter is the dominant component of our Milky Way. Our galaxy would fly apart if it wasn't for the presence of this dark matter. It simply rotates too rapidly to be held together just by the hundred billion or so stars of the Milky Way. There has to be a significant additional amount of this dark matter. And as a consequence, because our sun and solar system is moving through the Milky Way, a flux of these dark matter particles, hundreds of billions of these particles, are going through our bodies each second, but we've yet to ever directly catch one actually interacting, which is what the goal of the experiment is."
What's the point of looking for dark matter?
"Right now 95 percent of the universe is made of stuff we have no idea about. I don't know whether that keeps you up at night. But it is a surprisingly high level of ignorance, and we would like, even though we've been enormously successful over the last 25 or 30 years at getting a clearer picture of how our universe is put together, it's raised more questions in some areas than it's answered. This composition of what the dominant mass of our universe is remains one of the major scientific and cosmological questions of the start of the 21st century."
Is it possible that there is no dark matter?
"Oh, yeah. The nature of any scientific endeavor is that it has a speculative component. If it were certain, to be honest, it wouldn't really be science. It certainly wouldn't be scientific research. The idea is that we have tried to piece together all the information that we have from the many astronomical science missions that have occurred over the last 30 years ... and we have a very clear picture that there is this dark matter."