In Antarctica, one of the coldest climates in the world, a handful of world-class scientists are swimming in a square wooden tank. Submerged in chest-deep water and wearing only swim trunks, ice forms in their hair as clouds of frost rise around them.
The dip in the pool is a reward after weeks of grueling work. Since 1993, approximately 100 scientists from the United States, Europe and Venezuela have worked on the AMANDA Project, which stands for Antarctic Muon and Neutrino Detector Array. The venture turns parts of the South Pole into a telescope that studies the universe by sensing "neutrinos" rather than light.
"Neutrinos are small particles that are created in astrophysical processes like supernovae and gamma ray bursts," says Joakim Edsjo, an associate professor in theoretical physics at Stockholm University, who used to be involved with the AMANDA Project.
Modern telescopes use light waves to detect celestial bodies. But light moves slowly, so the picture we get is centuries old. Neutrinos, on the other hand, pass right through dense media and move much more quickly. They don't diminish over distances, thereby providing a much more accurate picture.
Neutrinos are difficult to detect, but as it turns out, the South Pole's almost 2-mile-deep crust of pristine ice provided the ideal medium. The ice causes a complex reaction with the neutrinos, which makes them easier to detect. Scientists create a telescope by lowering 19 strings of detectors about 1 1/2 miles into the ice.
To drill into the crust, scientists spray the ice with hot water, which is held in a plywood tank with a tarpaulin liner. Drilling is done between October and February; when it's completed, the scientists let the water cool off, then jump in.
"It's a weird feeling, swimming in this hot water in such a cold, remote place," Edsjo says. "It is extremely quiet and bright at the pole, so it is most unnatural to float around in this comfortable hot pool, feeling the cold air around you--and the ice building up in your hair."