BIOLOGY Mario Capecchi Phyllis Coley James Ehleringer James Ehleringer CHEMISTRY Joel Miller Thanh N. Truong Peter J. Stang MATHEMATICS Graeme W. Milton Jim Carlson PHYSICS James W. Cronin Charles Jui Craig Taylor Valy Vardeny

Cosmic Rays Keep Cronin Happy By Paula Huff U. College of Science      James W. Cronin counts himself one of the luckiest and most content people on earth.      He won a Nobel Prize in 1980. He taught physics at Princeton, then moved to the University of Chicago where he is an emeritus professor. Now, from a new position in the University of Utah's Department of Physics, he is leading a worldwide attempt to find the source of cosmic rays.      "When I ask myself, 'Who are the happiest people on the planet?' my answer is, 'Those who can't wait to wake up in the morning to get back to what they were doing the day before,' " said Cronin, who accepted a five-year faculty appointment and will teach students at all levels.      Cosmic rays equal happiness for Cronin, a world leader in ultrahigh-energy gamma-ray astronomy. These ultrahigh-energy atomic nuclei are the most energetic particles found in the universe. One entering the earth's atmosphere carries the energy of a fast-ball pitch by Ryan Nolan. Little else is known about them. Their source is unexplained; they are simply hurled through space by some powerful force.      Unraveling the mysteries of cosmic rays keeps this 66-year-old zooming around the globe convincing 18 nations and a team of 160 scientists to collaborate on $150 million observatories in Argentina and Millard County, Utah.      Why Millard County? It has a large, flat unpopulated area, said Cronin. More importantly, it is near the University of Utah, a hot bed for astrophysics.      "By building in Utah, we hope to engage the expertise of people at the University of Utah," he said.      Called the Pierre Auger Project, it is named after a French physicist. In 1938, Auger discovered that when a cosmic rays enters the earth's atmosphere it bumps into particles, which collide into other particles and cause a cascade of movement. He called these "air showers."      University of Utah scientists hoisted themselves to the forefront of cosmic ray research in 1991 when the Fly's Eye project detected a cosmic ray with the highest known energy.      University researchers had built the Fly's Eye to demonstrate that high energy cosmic rays could be detected optically. Using large mirrors, sensitive phototubes and fast electronics, the scientists recorded cosmic rays with the brightness of a flashlight bulb that moved at the speed of light. Experiments were conducted from 1980 to 1992.      The original Fly's Eye has been replaced by the High Resolution Fly's Eye, which has large mirrors, more phototubes and is 10 times more sensitive. But cosmic ray detection is entering another era. Pinning down their source is the new goal. That's what Cronin hopes the Auger Project will do.      Each Auger observatory will have two types of air-shower detectors:      About 1,600 large water tanks will be scattered on the 1,200-square-mile Millard County site. These will catch air-shower particles.      Three fluorescence detectors at each site will measure faint blue flashes from air showers.      Cronin's interest in science began as an undergraduate at Southern Methodist University in Dallas, Texas. He moved back to his hometown of Chicago for a Ph.D. at the University of Chicago, Illinois. Then he was off to Brookhaven in 1955 as a postdoctoral student.      It was at Brookhaven that Cronin met Val L. Fitch. Years later Fitch would build an apparatus that was a layer of plates. When a cosmic ray moved through this, its tracks could be seen. Cronin had developed a similar apparatus where the paths of high energy particles could be seen.      "About the same time there were some funny experiments going on that were wrong," he said. "Originally, Fitch and I set out to do an experiment that would prove this."       Like many scientific discoveries, the Cronin-Fitch team ended up answering a different question. They described CP Violation, a phenomena that explains why our universe is mostly matter rather than equal parts matter and antimatter. A paper was published in 1964. It's importance was not fully recognized until 1980, when the Nobel Prize was awarded.      Cronin continued working on CP Violation until 1971, when he left Princeton for the University of Chicago. His focus shifted slightly to particle physics. The experiments were "beautiful, intellectually important and well-defined," he said. One problem: thousands of people participated. Cronin wanted research on a smaller scale.       Cronin was thinking of other science problems to undertake when the University of Chicago hosted Professor Cassidy, founder of the Fly's Eye.      "At the time there were a number of curious phenomena that came about because cosmic rays were coming from points in a galaxy," said Cronin. "These cosmic rays were not of high energy. I wanted to understand their scale. That brought me into the area of cosmic rays. I wanted to measure them to a high precision. They are so poorly understood that I decided I had to build something. That was the birth of the Auger Project."       The Auger Project in Millard County is informally on hold. Physicists on a federal advisory committee decided there are scientific reasons for constructing the observatory in Argentia first. Cronin is determined to see the Utah observatory completed, so cosmic rays can be recorded in the northern and southern hemispheres.      "I want to find out the answer to cosmic rays," he said.