The art of flaking

Skiers and boarders lusting for hard pack or waist-deep powder see a white-flecked sky and whoop.

Poets get as giddy as Henry David Thoreau, who gushed into his journal: "I should hardly admire them more if real stars fell and lodged on my coat."

Even physicists swoon over nucleated ice.

Cal Tech professor Kenneth Libbrecht, for one, recites the names like incantations: stellar dendrites, sectored plates, columnar crystals. He takes portraits of snowflakes. He wrote a book about them.

Lots of seemingly serious adults understand.

"Snow is wonderful, paradoxical stuff," says Bernard Mergen, author of "Snow in America." "It's so fragile when it falls as a single crystal, but then it accumulates and depending on the volume and density, it becomes massive and life-threatening for weeks and months at a time. It blocks roads and causes avalanches."

Brian Swanson, a researcher in the Earth and Space Sciences Department at the University of Washington, explores the speed-producing side of the substance. "The shape of snow crystals and the temperature can affect the quality of skiing," he says. "It explains the difference between the snow in Utah and the snow in the Cascades."

And John Hallett, atmospheric director for the Desert Research Institute in Reno, admires snow's simple complexity. "Aesthetics are a driving force for any study of snowflakes," he says. "There is a great elegance about them. By understanding their symmetries, you can interpret how those crystals grew in the atmosphere."

Snow, in fact, seems to hold equal fascination for practical and dreamy folks alike. "Once I got into snow," says Mergen, "I was surprised to discover that scientists and poets are doing the same thing ... Science and art are really two ways to approach the vast ineffable nature that we live in."

For Libbrecht, that two-fold fascination began in the naturally snowy world of Fargo, N.D., where he grew up on his father's farm. A self-described math nerd, he spent his youth shoveling driveways, throwing snowballs and building ice forts. Snow was something he took for granted, until after nearly 20 years in Pasadena, he put aside the world of helioseismology -- oscillations of the sun -- and once again stepped into the cold.

Like any good researcher, he began poring over the books: Descartes and Robert Hooke, 17th century scientists who published the first accounts of snowflakes; William Scoresby, an Arctic explorer who sketched snowflakes by hand while writing a history of the polar whale fishery; and the great 19th century snowflake amateurs, Frances Chickering, the minister's wife from Maine who deftly cut paper outlines of their shapes, and Wilson Bentley, a Vermont farmer who took the first snowflake photographs.

Enthralled, Libbrecht decided he too wanted to shoot snowflakes. Educating himself in the world of macro- and micro-photography, he set about building a camera that could capture these hieroglyphs from the sky, as Bentley called them. The contraption Libbrecht devised -- a combination microscope and a Nikon D1X digital camera -- fits perfectly in the back of his Honda SUV -- an important consideration since snow seldom falls in a laboratory.

For the glamour shots he was after, there could be no bright lights, no studio setting. Libbrecht enlisted the help of photographer Patricia Rasmussen, who set the camera up in her garage in Wisconsin, where the winter temperatures hover between 5 and 10 degrees Fahrenheit. The challenge was to capture a flake before it melts -- a window of about 20 seconds.

A snowflake snob, Libbrecht took his camera on a road trip last winter to Tahoe, Yosemite and Sequoia. The quality of snowflakes in the Sierra, he will tell you, stinks. "Too warm, too rimy. This year we're heading up to Ontario." He prefers flakes with the most facets, that refract the light from every angle, that twinkle as they tumble down. "Twinkling is a good sign," he says.

When the conditions are right, the results astound. Like the photographs of Harold Edgerton, which revealed what a balloon looks like when a bullet has pierced it and what a drop of milk looks like when it hits a full saucer, Libbrecht's pictures combine science and art to capture the fleeting and the ephemeral. When you look at them, enlarged on the page in all their splendor, it's hard to believe that they are in most cases no larger than a pencil eraser.

Voyageur Press recently collected Rasmussen's photos and Libbrecht's obsession -- he calls it a hobby -- in a book, "The Snowflake: Winter's Secret Beauty. " It tells the story of a scientist-turned-naturalist who isn't afraid to ask basic questions: How do snowflakes get here? Why are they hexagonal? How do they form? And why are we surrounded by so many things we don't understand?

Taking pretty pictures is only half of the story. The real puzzle is how a snowflake forms. Libbrecht reaches behind his desk, his face flushing with enthusiasm. At 45, he still looks like a farm boy. He grabs a small piece of stone, so silver it seems as if it were painted.

It's a crystal of silicon, he says, a gift from his wife, and the reason for society's preoccupation with crystals. Valued for their electrical properties, crystals are a multibillion-dollar enterprise, and although none of that money goes toward snowflake studies, Libbrecht hopes his work with snowflakes will one day help explain how crystals such as silicon are created.

Libbrecht leans back in his chair to describe the dynamics behind snowflake formation. "The basic principle to remember is this: Ice grows and water shrinks."

The physics professor you always wish you had, he holds up his hands, palms wide to show a cloud, then two fists -- one expanding like an ice molecule and the other contracting like a water molecule.

"Ice nucleates on the crevice of a speck of dust," he explains. "It then grows out and soon envelops the dust ... " A photograph of one flake, taken with blue and white lights, hangs on the wall above his cluttered desk-- the image fragile, aqueous and strangely indelible.

As Libbrecht describes the atomic intensity inside a winter storm, it's easy to feel a chill and imagine a soup of microscopic particles -- water, dust and air -- tumbling and turning around him in the air.

"At first," he continues, "the ice is a hexagonal prism, only about a 30th of the diameter of a human hair. Then, in most cases, the sides begin to grow, turning the prism into a thin, flat plate."

One snowflake is born. Then another. Then millions. A cold front churning at 4 degrees Fahrenheit shoulders its way beneath warm pockets of air and shoots them aloft, condensing more and more moisture off the ocean and the land. It clocks down the coast -- Seattle, Portland, Crescent City -- and skiers and snowboarders in Southern California start packing their cars.

"As the crystal grows, the plate branches and blossoms. It gets heavier and heavier and then it falls from the sky."

Libbrecht drops his hands. For the moment the room is still.

Across the hall from Libbrecht's office is the laboratory, where a 4-foot-high, 2-foot-diameter vacuum tank, wrapped in white insulation, sits on a raised platform. An engine hoist holds aloft its lid, from which curls a skein of electrical umbilicals that run to a pair of television screens.

Inside this tank, Libbrecht creates his own snowstorms and studies the growth velocity of snowflakes. So far he has learned that a flake's growth rate depends on temperature and the presence of other gases in the air, findings that have implications for skiers and climatologists alike.

There are those who might argue that dissecting a snowflake is for scientific spoilsports, akin to reading a sonnet into an oscilloscope.

Libbrecht responds to that slur with a quote from his Cal Tech protege, Richard Feynman: "It does not do harm to the mystery to know a little about it. For far more marvelous is the truth than any artists of the past imagined it."

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