December 22, 2000
UW-RF Physics Professor to Spend Holiday Break on Polar Icecap
While most of us are anticipating a magical visit from a jolly fat man who comes from the North Pole in a sleigh, a physics professor at UW-River Falls will be packing for his departure on Christmas Day for the South Pole, where he will immerse himself in another kind of magic: the mysteries of science.
Jim Madsen, associate professor at UW-RF, will travel to the South Pole on a two-week adventure, and his mode of travel will be more conventional than Santa¹s. He will take a commercial flight to New Zealand, then travel by military aircraft to a U.S.-run station on the coast of Antarctica, and fly from there in a small plane to the South Pole. His job will be to calibrate a remarkable telescope, making sure things are operating as they were designed to.
The telescope, or Antarctic Muon and Neutrino Detector Array (AMANDA), is the world¹s largest detector of the mysterious neutrino. Neutrinos are the most prevalent objects in the universe. They pass through the earth unhindered, as no other known particle can do. The fact that they interact only weakly with matter makes them ideal astronomical messengers. Scientists are hoping that the neutrino‹a particle that is almost nothing‹may reveal everything about the universe.
To install AMANDA, astronomers melted holes two feet wide and more than a mile deep in the Antarctic ice cap. In these holes they buried nearly 700 sensors that compose what Scientific American magazine called "the weirdest telescope in the world;" a telescope that looks down while others look up.
Francis Halzen, a physics professor at UW-Madison, came up with the idea for AMANDA in 1990. Installation and assembly of AMANDA began in the Antarctic summer of 1992, using technology for hot water drilling that geologists already had invented to cheaply deploy equipment in ice. Construction of the AMANDA detector followed in 1993, and Amanda began collecting signals at the rate of about one every second.
Today, the operation involves about 75 scientists from 17 institutions in Germany, Sweden, Belgium and the United States. To this point, the project has spent about $10 million. It has been funded by the National Science Foundation in the form of grants to the University of California at Irvine and the University of Wisconsin at Madison, among others, with support also from the Swedish Wallenberg Foundation and DESY, a German national laboratory.
Madsen, who completed his undergraduate work at UW-Madison, says that until 18 months ago he didn¹t do any work with high-energy physics. His background is in low-temperature physics and polymers. He began working on the Amanda project as part of a sabbatical project, and became fascinated with it.
This will be his first trip to the South Pole, and he is glad to be going there during the warm season, when the temperature is about 15 F. Because the seasons are reversed south of the equator, they are opposite the seasons north of the equator. "Summer at the South Pole is from the end of October through mid-February," he said. "During this time, people can get in and out. From mid-February through the end of October, nothing moves."
"The South Pole is colder than the North Pole, and except for animals such as penguins and seals along the coast, there is no animal life," Madsen said. "There is not a lot of snow, but there is a lot of wind," he said. "It is considered the most remote place on earth."
Antarctica is the ideal place to operate the telescope. It is a land mass, with a layer of ice over it that is two miles thick. Because ice is a totally sterile medium, almost completely free of radioactive materials such as potassium, it is a friendly place for neutrino detectors.
Madsen said many of the facilities for the project were already in place at the South Pole. The National Science Foundation operates a research station there, with an infrastructure that is comparable to that of a national laboratory. Everything they could possibly need is available to them, from a 50-foot crane, a heavy-duty vehicle or a snowmobile, to trained support personnel, a cafeteria and living quarters.
In addition to offering a contribution to science, the project is providing an educational opportunity for hundreds of secondary school students.
Last August, teachers attended classes on the campus of UW-RF to prepare them to introduce the exciting science of the AMANDA project to their students. The classes, taught by Madsen, Halzen, three graduate students and one high school teacher, focused on the creation of activities to use as classroom projects. The instructors from the course are available for a classroom visit to each school, and to provide ongoing support. The course will be offered again next summer.
As innovative as AMANDA is, it is only a prototype, and scientists are already looking ahead to new possibilities. They are building a new detector, comprising nearly 5,000 modules scattered through a cubic kilometer of ice. It is known as IceCube, and it is capable of detecting neutrinos from the farthest edges of the universe.
The history of science shows that forays into new energy regions have invariably resulted in the discovery of new phenomena. Because neutrinos are the only messengers that can provide direct information about the most violent cosmological events, it is an exciting possibility that something completely unexpected will be discovered as a result of exploration with AMANDA and IceCube.
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