More Tales of Mystery and Observation

December 1st, 2010

When I stepped out early Saturday morning, the air seemed relatively warm, particularly compared to the cold snap we had last week. Indeed, it was much warmer, and yet the parking lot in our apartment complex had a glaze that was much more dangerous than that during the cold snap.

But it was the frost that I noticed. Of course, the air was relatively warm, but the clear sky cooled the surface. Recently, snow melted, leaving plenty of open water to evaporate – perfect conditions for film frost and hoar.

I saw “striped-tail” film frost(1) on two car roofs, both times on the sunroof glass. Why only on the glass? Perhaps the glass, being a poorer conductor of heat, had a lower surface temperature. This lower temperature would have produced a thicker film of water, and the thickness of the film seems to influence the pattern. The bigger mystery though is the cause of the pattern. In a short online article(2) last year, I suggested a cause for the stripes on each tail, though I can offer no explanation for either the nearly uniform width of the tails or the meandering. In the case below, the pattern is dense with lazily wandering striped tails. When I look at it, I think of seaweed.
The metal car surfaces often had nice curving film-frost with dense hoar, while others had or condensed droplets with more isolated, spiky hoar. The latter appeared on my own car.

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2011 AAAS/Subaru Science Books & Films Prize Nominee.

October 10th, 2010

The Story of Snow  has been nominated as a finalist in the has for the 2011 AAAS /Subaru Science Books & Films Prize for Excellence in Science Books.(AAAS stands for American Association for the Advancement of Science.) Nice to learn about this on the fall weekend when I cleaned out my garage to prepare for another season of snow crystal photography.

Read more and see the other fianlists at http://www.sbfonline.com/Subaru/Pages/Finalists2011.aspx .

Mermaid Affair: A Celebration of Water

May 31st, 2010

A fascinating art exhibit dedicated to water in all its many forms will be opening June 1, 2010, at the Commerce Pointe Gallery in Battle Creek, Michigan. I contributed a couple of large snow crystal prints for the exhibit - which I believe are the only photographs of water as snow in the event. With a little luck, copies of The Story of Snow will be on hand at the gallery.

The opening reception will be Friday evening, June 11. The exhibit closes August 31, 2010.

For details, see a-mermaid-affair.net.

New Review in the Cleveland Plain Dealer

March 28th, 2010

On March 14 the  Cleveland Plain Dealer reviewed several children's picture books that deal with snow. The Story of Snow was on the top of their list, being described as a "dazzling nonfiction picture book." You can see the whole review here.

 

Japanese Edition Coming Soon!

March 13th, 2010

An interesting package arrived in the mail earlier this week - it contained a couple of advance copies of The Story of Snow, Japanese edition. Here's a scan of the cover - the book is a bit smaller (physical dimensions) than the US edition. How cool!

 

- Mark

A Few Irregulars

March 7th, 2010

I hear the birds sing in the morning - the Cardinal with his 'bomb drop' song, the slurry scrabbly song of starlings at first light, and the 'To-hee to-hee chickachickadeedeedee' of Chickadees - the only bird that sings in deep winter, and gets all the more enthusiastic as spring starts to show.

Snow crystal season is coming to an end - another year.

Photographing snow crystals is a funny thing. I tend to select the best and the brightest, the most symmetrical, the most regular, the most ... extraordinary. It is a biased selection process, for sure. I wipe away thousand of snow crystals in an evening, and take photos of only a few dozen. There is a huge selection bias in play in the photos of snow crystals that are presented...

Of course - no one wants to see photos of the imperfect, the unsymmetrical, the broken or worn. That would be like walking down the street and looking at those passing by... Show us Hollywood Celebrities - the paragons of glamour - and not the ordinary dust of creation.

What can I say? It would be dishonest to ignore the vast numbers of irregular and flawed snow crystals. They outnumber the perfect ones one an incredible scale. So here are a few imperfect crystals - I have to say, they are more perfect than not, in that the truly disorganized have been ignored.

Irregular Snow Crystal

So - how many arms are on this crystal? I vote for ten, but it looks like nine or eleven are possible answers as well. And I thought snow crystals grew in multiples of six - but maybe not when they break up, fracture, grow and re-grow again.

Here's a crystal that is a little asymmetrical. It also has an interesting feature in that one pair of arms have grown across the center.

Irregular Snow Crystal

Here's another show showing a similar center band - the crystal was not laying flat on the glass, so the edges of the arms are visually soft.

Irregular Snow Crystal

 A snow crystal grows with a lack of symmetry when it lingers near a source of water on one side - lie passing by a big rain drop in the clouds - that creates a different in the relative humidity between one end of the crystal and the other. Here are three snow crystals showing this lack of symmetry - 

Irregular Snow Crystal

Irregular Snow Crystal
Irregular Snow Crystal

Here's a simple snow crystal that is a composite of three individual snow crystals - or were they really ever individual, or did it just start growing from three nearby nuclei?

Irregular Snow Crystal

And lastly - here is one that is not irregular at all. I think this is a Magono-Lee P6d - stellar with spatial dendrites.

Irregular Snow Crystal
Maybe next winter I'll come up up with a system to tak ejust a sandom sample of the snow crytals that fall - how many are imperfect or not?
For now I lokk forward to the inevitable change over to spring - the longer days, the singing birds, the greening of the trees and brush...
- Mark

 

Chicago Public Library "Best of the Best - 2010" List

February 20th, 2010

The Chicago Public Library recently published its "Best of the Best 2010" list - and The Story of Snow is on it! The library describes the list as including books that are "some of the very best published for kids in 2009."

You can see the whole list here:

http://www.chipublib.org/forkids/kidsbooklists/bestofbest_list.php

And here's a celebratory dendrite photo -  I reckon the subject is a P1e. It seems to have melted a little somewhere in the course of its existence, as the center areas of the arms in the lower left quadrant have smoothed out a bit.

 

Snowflake Photograh
- Mark

More Snowflake Photographs with Classifications

February 17th, 2010

I found Jon's post regarding the Magono-Lee Snow Crystal classification system to be quite interesting.  Here are some more shots from Monday night - I'll see if I can classify them... something tells me that will be more difficult than it sounds.

Let's start with something simple.  My first guess is that the two crystals that  follow would be classified as  P2d  - Dendrite with Sector-like ends:

It looks like that crystal bumped into a couple of simple plates along the way, and they are stuck to it in the lower right quadrant.

The one below has one spot of rime on it - which I assume is not enough to knock it into the rimey category, so it too is a P2d:

This one is similar in general form to the one above, but has a bit of rime spotting it up. I guess it would fall under rimed stellar R1d under Magono-Lee's system. Personally, I think it would make more sense to have rime as a qualifier of the basic shape, so if I was cooking up a classification scheme I'd call this a Dendrite with Sector-like ends with moderate rime. Maybe P2d-r2.

The next one is a 12 branched crystal without rime, so it is either a P4a (broad branched with 12 branches) or a P4b (dendrite with 12 branches.) Personally, I'd call it a 12 branched variant of the P2d formation, which we just saw above. Maybe P2d-2x? Well - under the existing system it is either a P4a or P4b...

You may have noticed what looks like a sectored plate emerging from one arm at about the 8 o'clock position - that appears to be a growth at the end of that arm.

OK - let's get back to something simple.  I think the following are all ordinary dendrites - P1e.

This first one has a 'crack' in the center plate - something I've seen several times. I'm not sure what causes it.

And I'll close out with three rimey subjects, the first two would be R1d - Rimed Stellar and, I think, the last one would be R2b - Densely Rimed Stellar. Though one might think it was a densely rimed fernlike stellar dendrite - maybe P1f-r3, eh?

Magono-Lee is an interesting classification system. I don't understand exactly why it places such an emphasis on rime at the expense of the core structure of the crystal. It seems to me that rime is an incidental condition independent of the core structure of the crystal. Classifying rimey crystals as a distinct group is sort of like lumping all molting birds into a distinct group. But just as Nietzsche  observed that histories reveal almost as much about the historians who wote them as about actual past events, I'd speculate that classification systems tell us a bit about the people who developed them as well as the subjects being classified. Maybe rime was important to Magono or Lee...

So - how many did I get right, Jon?

- Mark

Three From This Evening

February 15th, 2010

A gentle snow has been falling this evening. Here are some snowflake photos, more will be coming:

Snow Crystal Photo
Snow Crystal Photo
Snow Crystal Photo
Click for larger images.
- Mark

The Window of Many Cacti

February 14th, 2010
It’s been two weeks since our last frost, and judging from my first dozen shots, it seemed like my photography skills dropped from mediocre to downright pathetic. But then I got a few good shots of frost on windows. The fact that I shoot windows on cars means that I see some special forms that would not normally appear on house windows. The most common type I call ‘cactus frost’ because of its resemblance to saguaro cacti.



The resemblance may be a bit more obvious in the following shot, which I took two years ago on seeing this form for the first time.

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