Holiday Stamps Close-Ups of Snowflakes

By RANDOLPH E. SCHMID
The Associated Press
Monday, October 2, 2006; 2:14 PM

WASHINGTON -- One of nature's most lovely creations sometimes blankets large areas but rarely gets the close look it deserves. But take photos of just four snowflakes, print millions of copies, and you have this year's holiday postage stamps, being issued Thursday in New York and on sale nationwide Friday.

The 39-cent stamps feature photos taken by Kenneth Libbrecht, a physics professor at the California Institute of Technology.

A native of North Dakota, Libbrecht was quite familiar with snow, but didn't start studying it up close until he became a physicist.

"You're more likely to study snow when you don't have a shovel in your hand," he joked.

Libbrecht got interested in how crystals grow, and snow seemed a logical place to look. After all, he said, it's just water, so the materials are cheap and there are no safety concerns.

And the actual physics of the process wasn't well understood, he said.

"It's not trivial," he added. "It's really kind of a fundamental puzzle."

So he began making chambers to produce snow crystals in the lab, and began photographing them when he realized that there weren't a lot of good images available.

The basic reference work was done decades ago by Wilson Bentley, a Vermont farmer, with primitive optical equipment.

"Now we've got digital cameras and things he could only dream of," said Libbrecht, who is working on his fifth book about snowflakes.

So, if he has studied snowflakes so much, has he ever seen two alike?

The crystals made in the lab are very small hexagons and all look alike, Libbrecht said. "But out in the wild, when we look at these complex crystals, they are all different. It never gets boring."

The flakes on the stamps were photographed by Libbrecht in Michigan, Alaska and Ontario, Canada.

He used a high-resolution digital camera attached to a specially designed microscope. The snow crystals were picked up from a collection board using a small artist's paintbrush and placed on glass slides to be photographed.

The work was done outdoors in subfreezing temperatures with the camera placed in a heated box to keep it working.

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On the Net:

U.S. Postal Service: http://www.usps.com

Libbrecht's snowflake Web site: http://www.snowcrystals.com


© 2006 The Associated Press