Happy Holidays plus A Bit About Snow Crystals

As a kid growing up in Pennsylvania, we more often than not had a white Christmas.  So there are a lot of fond memories for me associated with Christmas time snowfalls and the Pennsylvania woods.  You might get a sense of that from these pictures that my brother, Doug took and posted on his face book page a while back.

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Doug - Snow on Berries  Doug - Snow on Fern 01

Doug’s the artist in the family.

There’s not much opportunity to take pictures like that here in Portland.  It think our last white Christmas might have happened in 2009.

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Actually, now that I think about it, we had a white Christmas for a couple of years in a row .  About the same time in 2008, we received about twice our annual snowfall in one event.

Snowstorm 01

That inspired my blog post about how Your Winter Wonderland can be a Facilities Engineer’s Worst Nightmare.  But snowfalls like that here are more the exception than the rule.

If you look at the picture above closely, you will see that the snowflakes, which are clumps of snow crystals, are really large.  Given what I know now, I wish I had spent more time looking at them.  But it wasn’t until I was trying to understand the ice spikes in my freezer that I realized what I was missing.

That’s when I found SnowCrystals.com, the web site of Kenneth G. Libbrecht, a Caltech professor of physics who studies crystal growth, including how ice crystals grow from water vapor.  That is the very phenomenon that causes snow crystals to grow and his web site is full of beautiful pictures and information about the topic.  I was going to stick a couple of his images in here to entice you to the site, but I think doing that may violate a copyright.  So I will simply, strongly suggest you visit the link above and look around for yourself.  I think you will find it is well worth the effort.

This year for Christmas, I bought copies of his book Field Guide to Snowflakes as Christmas presents for my grandkids.  In doing that, I discovered Dr. Libbrecht had a new book out.  So I bought a copy of it for Kathy and I and have been enjoying reading it in my spare time.  In addition to beautiful images, the book is a really great summary of the topic of snow crystals, including how they form, how to photograph them, and the history of their study, which is something I did not know anything about.

It turns out that the first person to photograph a snow crystal was a self-taught farmer named Wilson Bentley up in Vermont.  Here are a few snapshots from a video of him doing his thing.

Wilson Bentley at Work 02  Wilson Bentley at Work 03Wilson Bentley at Work 05  Wilson Bentley at Work 06

He started trying to figure out how to capture the images as a teenager and as I understand it, finally succeeded in 1885, so pretty amazing.  The snapshots are from a video that you get as part of a digital archives package you can order from the Jericho Historical Society (Jericho, Vermont was his home town).

The CD also includes thousands of his images, which are public domain, so I will share a few of them here, hoping at a minimum to inspire your imagination and maybe even to inspire you to visit the Bentley web site and get a copy of the CD for yourself since it will help support preserving his work.

00001  0000200003  0000900064  0007900119  0012000183  00196

The variety of shapes and patterns are infinite, something you can maybe get a sense of from this screen shot of the directory with the images in it, maximized to the full size of my monitor with the smallest image icon option selected.

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Once you understand how snow crystals form, you will understand why the old saying that “no two are alike” is probably true, at least in the natural world.  Ken Libbrecht does a great job of explaining that in his books and on his website.  He also shows how he grows crystals in his lab, where near identical twins are possible under the right conditions.

The first person to grow a snow crystal in a lab setting was a Japanese researcher named  Ukichiro Nakaya who developed the science of it, including starting to understand why some snow crystals are stars while others have shapes like plates, columns, bullets, and needles, etc.  It turns out, as you night expect, that the temperature and humidity levels the crystal is exposed to as it tumbles through the clouds has a lot to do with it.

Ultimately, he summarized is observations in a snow crystal morphology diagram a.k.a a Nakaya diagram.  Here is an example of it from Ken Libbrecht’s paper titled The Physics of Snow Crystals.

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In 1954, Dr. Nakaya’s research was published in the form of a book titled Snow Crystals: Natural and Artificial.  Since I have become somewhat obsessed with snow crystals for the past couple of weeks and like old books,  I poked around and found a copy  on Amazon, which I am anxiously awaiting.  But you can also get it in an e-book form from Harvard University Press.

So with that bit of seasonal science, I will wish you Happy Holidays and thank everyone who visits my blog over the course of the year.  I’m behind again on posting as its been a busy fall, but hope to catch up a bit over the holiday break.

Meanwhile, I hope that my little foray into snow crystals will inspire you stop and take a closer look the next time you find yourself in a snow flurry.  For me, its been quite comforting with things as they are in the world to realize that in the quite of a snowfall, I am standing in a flurry of miracles, as far as my eye can see.

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David Sellers
Senior Engineer – Facility Dynamics Engineering
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