Friday, February 5, 2010

The Art and Science of Snowflakes

We were promised a dusting of snow a few nights ago, and sure enough, an inch of light and crunchy snow fell in the night. Dover couldn't even wait for sunrise to get outside and make dog snow angels on the terrace. The previous snow cover had been around too long - it was old and worn, melted and refrozen, and had tufts of dead grass showing through the surface. Our yard was so troden upon by Dover's relentless pursuit of tennis balls that it was treacherous going for non-dogs. 

Decades ago, a graduating student gave me a copy of a book that contained 2543 pictures of snowflakes. They were all taken by a Vermont farmer, W. A. Bentley; the book of his photographs (see the bottom photo) was published in 1931, the year he died. I have used the book and photographs in classes and given it, in turn, to many other people. The photographs are unbelievably beautiful.

More recently. I have come across the web site of another photographer of snowflakes, Kenneth Libbrecht, a physicist at CalTech. He also has gorgeous books - picture upon picture of snowflakes (left). I particularly recommend his children's book - The Secret Life of a Snow Flake - which, like the Bentley book, has photographs that are drop-dead gorgeous.

All snowflakes are based on six-fold symmetry, I don't think anyone has ever seen an eight-sided snowflakes except on knitted winter hats. The local science store hangs a mixture of 6 sided snowflakes and 8 sided pseudosnowflakes from the store ceiling in the winter. Both Tom and I, separately, talked to the owner about their error, but our words fell on deaf ears. His defense was that if he couldn't have 8-sided snowflakes, he wouldn't be able to sell dragons.

There is an exquisite precision about the 2453 photographs in Bently's book. Page after page, snowflakes based on six fold symmetry demonstrated in 2453 different crystalline patterns.

As I write, the snowfall of a lifetime is pelting down on Washington DC - buckets of snow in the night, as one news source put it. Up here in New England - we have only the old snow, old ice, and the pittiful pieces of old brown grass peeking through holes in the thin, patchy and slick ice and snow cover. 

[These snowflake photos are used according to the guidelines posted on the websites linked above. Visit the sites, and buy the books! Dover gave his okay to use the picture of his snow angel and tennis ball arrangement.] 

No comments:

Post a Comment