Job title:Hilldale and Gregory Breit Professor of Physics; Principal Investigator of IceCube
Location:University of Wisconsin, Madison, Wisconsin
 How do you explain your job at cocktail parties?
We are building a particle detector buried more than a mile under the ice at the South Pole. It takes a picture of the universe—exploding stars, gamma-ray bursts, and other cataclysmic phenomena—using neutrinos rather than light. Neutrinos are subatomic particles that lack an electric charge produced by the decay of radioactive elements. Or as the Nobel-winning Frederick Reines described them, “the most tiny quantity of reality ever imagined by a human being.” They pass through almost all matter undisturbed and are therefore very hard to detect. More than 50 trillion neutrinos pass through the human body every second. Some of us are more interested in the neutrinos than in the picture they provide. Our detector is also a powerful tool to shed light on the mysterious nature of dark matter.
 In the past six months, what has been the most exciting advance or breakthrough you’ve had in the lab?
(Almost) completing the detector. This is about proof-of-concept technology. We found a way to build a kilometer-scale particle detector. The ultra-transparent Antarctic ice itself is the detector. We’ve surrounded a large volume of it, one kilometer on each side, with more than 5,000 light sensors. It may not be a very good one, but it is by far the biggest ever built and that is the goal.
 Complete this sentence: We could make huge strides in the field, if we could just figure out…
What dark energy is. Deciphering its origin will almost certainly reveal totally unknown physics.
 What’s the biggest misconception about your field?
That it is a waste of money. My previous employment was at CERN, and they teased apart many of the network concepts that ultimately became the World Wide Web. Particle physics have already paid back to society. It is an example of how there is almost never a straight line from basic to applied research.
Click to view slideshow. Image courtesy of the National Science Foundation
 Scientist you’d most like to meet?
No hesitation: Enrico Fermi—the late, great physicist responsible for the nuclear reactor and much of quantum theory.
 What are you reading now?
A book by Robert Hughes called Barcelona: the Great Enchantress on the history of the city’s architecture. I was going to a meeting there but the National Science Foundation scheduled another review of the IceCube project.
 When I was a child, I wanted to be…
A Tour de France winner; I was born in Belgium.
 What advice would you give someone just starting out in your field?
Do not do it for the money.
 If the NSF surprised you with a $2 million grant tomorrow, what would you spend it on?
Yet another search for dark matter. We are actually thinking about burying an instrument in the sterile Antarctic ice, preferably under IceCube that can be used to measure and reject background.
 Why do you do science? What inspires you?
I can’t resist not to. The thrill for me is learning itself, not just discovery.
Originally published April 15, 2010