Toward a Grand Unified Theory of Snowflakes

Summary

Kenneth Libbrecht is that rare person who, in the middle of winter, gleefully leaves Southern California for a place like Fairbanks, Alaska, where wintertime temperatures rarely rise above freezing. There, he dons a parka and sits in a field with a camera and a piece of foam board, waiting for snow. Specifically, he seeks the sparkliest, sharpest, most beautiful snow crystals nature can produce. Superior flakes tend to form in the chilliest places, he says, like Fairbanks and snowy upstate New York. The best snow he ever found was in Cochrane, in remote northeastern Ontario, where there is little wind to batter snowflakes as they fall through the sky. Ensconced in the elements, Libbrecht scans his board with an archaeologist’s patience, looking for perfect snowflakes and other snow crystals. “If there’s a really nice one there, your eye will find it,” he said. “If not, you just brush that away, and you do that for hours.” Libbrecht is a physicist. His lab at the California Institute of Technology has investigated the internal structure of the sun and developed advanced instruments for gravitational-wave detection. But for 20 years, Libbrecht’s passion has been snow — not only its appearance, but also what makes it look the way it does. “It’s a little embarrassing when stuff falls out of the sky, and it’s like, ‘Why does it look like that? Beats me,’” he said. Kenneth Libbrecht, a physicist at the California Institute of Technology, in Cochrane, Ontario in 2006. When a high-quality snow crystal lands on his foam-core board, he picks it up using a small paintbrush, places it on a glass slide, and puts it under the microscope for further inspection. Courtesy of Kenneth Libbrecht For 75 years, physicists have known that the tiny crystals in snow fit into two prevailing types. One is the iconic flat star, with either six or 12 points, each decorated with matching branches of lace in a dizzying array of possibility. The other is a column, sometimes sandwiched by flat caps...