Keep your head in the clouds

This October, the US Postal Service will be releasing a set of stamps dedicated to ... clouds. That's right, clouds - as in, "Bows and flows of angel hair, and ice cream castles in the air." (Or perhaps just things that, "only block the sun...rain and snow on everyone" - depending on your point of view.)

Now, clouds may not seem all that inspiring a subject for philatelic commemoration, especially when compared to great inventors or humanitarians (or Elvis), but they do have the advantage of universality. Almost everyone on the planet has seen them at some point, and most have seen them with a poetic eye at least occasionally.

By the same token, just about everyone has seen rainbows, especially impressive sunsets, or even 'glories,' and may have wondered how such spectacular and diverse displays could have arisen from the simple presence of dust, water droplets, and ice crystals. Atmospheric Optics explains the mechanics behind these light shows - and manages to do it without taking away from the wonder.

Created by Les Cowley, a physicist and expert in these phenomena, Optics first catches the eye with a collection of genuinely impressive thumbnails - providing ample enticement, even at their minimal size, to draw visitors further inside. The second impression, as the eye takes a moment to wander away from the photography, comes from the site's almost unsettlingly basic layout. No logos or 'high concept' navigation bars, a monocolored background, standard fonts in a center justified design. It could almost give one the idea that there's not much behind this first page, but that would be an incorrect assumption.

To find out what's inside, the surfer simply clicks on one of the plain-text category titles gathered around the thumbnails. These divide the site into Rays & Shadows, Water Droplets, Rainbows, Ice Halos, and High Atmosphere phenomena. (A Contents page repeats these options with visual examples and a few words of introduction.) Once inside a category, Optics offers visitors a familiar left-side Index of the entire site, and Back/Forward arrows for sequential explorations.

Like the home page, each category page is decorated with a handful of striking images, in this case, one example to illustrate each atmospheric sub-category being explained - and there can be quite a few sub-categories. For example, Rays and Shadows offers eight variations on the theme, including Crepuscular Rays (commonly seen at pivotal moments in Hollywood Biblicals), Anti-Crepuscular Rays (commonly seen in Hollywood 'there'll be a new hope tomorrow' scenes), and even the occasional Double Sunset (usually only seen on obscure Hollywood planets in galaxies far far away). Sub-categories themselves can be further divided (eg., Sunsets can include the illusion of Flattened Suns, which can then include Ripples on the Sun's disc), but hierarchical indents in the site Index always keep your location clear.

Each section complements its computer-generated and photographic imagery with detailed explanations about how these spectacles are created - and while some may be a bit scientific for those of us who prefer to classify clouds by what they look like, even the technical elements can sometimes entice with the related gee whiz factor. (Nacreous clouds, visible up to two hours after sunset due to their extreme altitude, are composed of ice crystals at temperatures around minus 85 degrees C.)

And while the navigation and layout are basic, that doesn't mean the site doesn't have the occasional bit of extra interactivity. JavaScripted features include the ability to adjust the angle of light rays through a rainbow's water droplets, and for Windows users, downloadable software allows desktop simulations of glories, fogbows, coronae and the halos that frequently form around the Sun (sometimes accompanied by 'sundogs'). Recommended links and an alphabetical site index round out the offerings, along with "What's New" listings - largely comprised of fresh images as they are added to the collection.

On its opening page, Optics advises visitors that the site is, "Best viewed with Mozilla Firefox, Opera or Explorer and an LCD, 1024 X 768, 32 bit display." Personally, I was able to view the site with none of those recommended components, and (apart from the scrolling necessitated by my smaller screen) everything seemed to work fine - so you can probably relax if you're not up to standard as well.

The one surprise I did encounter related to something Optics' images taught me about the two browsers on my computer. Viewing the site in Netscape 7 (my default browser due to its adherence to Web Standards, and an equivalent to the pre-Firefox Mozilla), there was a frequent issue with gradient banding in some of the images - and the phenomenon didn't seem to change whether I set my monitor to thousands or millions of colors. (But if you like the 'posterization' effect, try viewing the site with your monitor at 256 colors.)

When I downloaded the images to my desktop and examined them with a JPEG-viewing application, they looked fine. So, for no reason that I can put down to logic or knowledge, I tried viewing the site in an old (older than my Mozilla clone) version of Explorer, and, like the JPEG viewer, the images were fine. Lesson: if there's anything wrong with the way a site is displaying on your computer, try another browser...you never know.

Of course, the best displays are the ones outside the window - but Atmospheric Optics does have the advantage of predictability.

Atmospheric Optics can be found at http://www.sundog.clara.co.uk/atoptics/phenom.htm.

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While we're on the subject, I'll mention an odd but interesting idea from the frequently odd but interesting BBC. In this case, Painting The Weatheroffers an online-only art exhibition comprised of more than 100 paintings, by 80 artists from 50 galleries - searchable by meterological criteria. While not as detailed as Atmospheric Optics -no Anti-Crepuscular options here- the site does offer 10 weather related choices (ranging from "Sunny Intervals" to "Heavy Rain"), with a handful of masterpieces in each category.

This is not to say that these paintings are simply a collection of sunsets and skies full of fluffy white clouds (works include Delacroix's "Christ on the Cross," and Peter Paul Rubens' "The Judgement of Paris"), but atmospheric conditions do play an important role in each composition. Choose an image, and Weather will load a 'zoomable' copy of the painting, with curator's notes about the weather's function in the work, and such additional details as the estimated temperature at the moment depicted. Selected images are also accompanied by RealAudio comments from the Director of the British Museum, as well as the qualified observations of a BBC meteorologist.

The legacy of a BBC Four television series, Painting The Weather at the very least introduces a new way to categorize art - and a much simpler one than that whole 'Post-Impressionist,' 'Pre-Raphaelite,' 'Neo-Abstractionist' system.