The adage that no two snowflakes are alike seems to still ring true. Because snow crystals are formed by fluctuations in temperature that occur on their journey from the clouds to the ground, it could very well be effectively impossible for two complex ones to be identical. The recent snowfall here in Washington, D.C. reminded me of our recently updated resource guide on snowflakes that contains a selection of useful books, articles, and online resources for researching the formation, properties, and history of snowflakes and snowflake observation. The guide also includes wonderful resources where you can find lots of snowflake images.
Early printed depictions of snowflakes are absolutely wild. One example that has lived rent-free in my mind for the past year is from Historia de Gentibus Septentrionalibus by Olaus Magnus. Including what could reasonably be interpreted as a snowflake, Magnus also added such wondrous shapes as an eye, arrows, and a human hand!
René Descartes came a bit closer than Magnus with the shapes he proposed for snowflakes. In his Discours, Descartes includes a section on snow, rain, and sleet in which he provides what appears to be 10 different shapes of precipitation, including one that resembles a daisy, another that is just a dot, and some that resemble stylized suns. Interestingly, he also added capped columns (fig. F) as one of the shapes which would have been very difficult to deduce without the use of a relatively high magnification. The capped column also happens to be my second favorite style:
Using compound microscopes, which had been around for the better part of a century, scientists from the latter half of the 17th century such as Robert Hooke were able to discern the minute, complex patterns of snow crystals for the first time; and they were in awe. From his 1665 book Micrographia:
“I have often with great pleasure, observ’d such an infinite variety of curiously figur’d snow, that it would be as impossible to draw the Figure and shape of every one of them…” p.91
Hooke was also one of the first scientists able to see that under magnification, snow crystals were not perfectly shaped but irregular:
“Observing some of these figur’d flakes with a Microscope, I found them not to appear so curious and exactly figur’d as one would have imagin’d, but like Artificial Figures, the bigger they were magnify’d, the more irregularities appear’d in them…” p. 91
Just as interesting as the inclusion of capped columns by Descartes is Hooke’s exclusion of them from his publication.
Close to a century later, John Nettis described his use of the compound microscope to view the intricacies of snow crystals. As printed in the 1755 volume of Philosophical Transactions, Nettis had quite the set-up:
“I first made use of double convex glass lenses of about an inch focus; then I used a compound microscope consisting of an object, and an eye glass, or two eye glasses…” with “the addition of a concave speculum, placed under the object glass, in order to reflect a better light, and rend the object more conspicuous.”
Nettis even took great care to not touch or breathe on the flakes so the “extreme exactness and equality of the figures of their most minute particles might be observed and delineated.” And this caution paid off:
Thanks to modern technology, we can now take pictures with our smart phones that prove some of these earlier depictions of snow crystals to be less than true. The next time it snows near you, I suggest grabbing your camera so you can see what beauty lies in these amazing crystals!