Friday, January 26, 2007

I think I've seen that one before...

More than you ever wanted to know about snow, and stunning photos to boot.

Also a discussion of some flaky myths.

Snow crystals are so perfectly symmetrical! ... Are there not some special forces at work that ensure this perfection?
People are sometimes convinced that the simple explanation of snowflake symmetry cannot be correct, because snow crystals are so perfect in form. These folks argue that the simple explanation would likely yield less ideal shapes, less perfect six-fold symmetry. Therefore they suspect something else is happening -- perhaps some acoustical or quantum mechanical oscillations are enforcing symmetrical growth, for example.

The flaw in this reasoning is the statement that snow crystals are all extremely symmetrical. You can disprove this for yourself if you simply go outside and take a close look at some falling snow. You will soon realize that the beautifully symmetrical specimens are hard to find! The rather unattractive irregular crystals are by far the most common variety (see the Guide to Snowflakes under the heading of Irregular Crystals for some pictures). Even on the best of days, I search for hours to find
just a few beautifully symmetrical specimens. I typically glance over thousands of crystals on my collection board before selecting one to photograph -- so already each photograph shows the best crystal out of thousands. And the pictures you see in the Galleries are some of the best among over 6000 pictures I've taken.

Alas, the vast, vast majority of snow crystals are not even close to perfectly symmetrical. The simple mechanism does indeed produce lots of imperfect symmetry, as you would expect. Snowflake photographers always select their most symmetrical crystals to display ... we have to, because no one ever seems to be interested in looking at the irregular ones!

One other wintry note - Do Inuits ( Eskimos) really have 100 words for snow?

The way this winter is going some of don't even need one word for snow. And then some of us...

[Thanks, Jack]

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