What does the snow produced by snow machines (the ones used to produce snow on ski slopes) look like on a microscopic level? Does it consist of elaborate, symmetrical snow flakes like the ones that fall naturally from the sky? If I took a sample of natural snow and a sample of machine-produced snow and put them on a piece of black construction paper, or under a microscope, would I be able to tell the difference?
Yes, you could tell the difference. Artificial snow is made up of fine pellets, not flakes. You can see an illustration in this article:
https://cosmosmagazine.com/technology/how-does-a-snow-machine-make-snow
And they ski differently, as well. It’s not hard to tell when you’re skiing on man made.
Though, most natural snow isn’t made up of those pretty, photogenic symmetric crystals, either.
I think that article isn’t entirely correct.
I’ve been out skiing on a sunny day when snow machines were operating, and when I got the correct angle between the sun and the new snow gushing out of the snow machine I could see ice crystal optical effects. Ice crystal effects are caused by sunlight refracting through hexagonal ice crystals (not, in general, those lacy snowflakes, even those have hexagonal symmetry. hexagonal ice crystals are mostly flat hexagonal “plates” or long "needles with hexagonal cross-section. Although some ice crystal halos can be formed by triangular ice crystals, which definitely exist). You do not get such effects from spherical ice particles – ice crystal halos aren’t like rainbows, and often are not strictly circular.
Thanks for all the responses so far. So if the machines used on ski slopes don’t produce the elaborate crystals that we see in (some) natural snow, is there any way of producing such crystals artificially? Can one grow natural-looking snowflakes in a lab?
I’ve had a quick look over the internet – although modern snow machine produce “hollow ice spheres”, older machines evidently made snow crystals
The book cited here shows a photomicrograph of artificial snow (Fig 3, p. 64) – it’s not really spherical
This looks like an interesting topic – optical effects of natural ice crystals vs. old and new snow-making snow.
Yes – look at the first reference I cite. It tells about growing artificial snowflakes in a lab.
It’s not the same thing, but there was an exhibit at the 1957 World’s Fair (which they later put on exhibit at the Boston Museum of Science for many years) that let you watch ice crystals forming in supercooled water. You could remelt and refreeze them over and over again. It’s not at the Boston Museum anymore, but it looks like another one (or possibly the same one, transplanted) is at the Exploratorium
Slightly off topic from the Covid thread in the quarantine zone and contributed by phychonaut regarding conditions in Austria, #2176:
“In the bizarre-but-true department: Tyrol has announced plans to use retrofitted snow cannons to efficiently disinfect large areas such as stadiums and train stations.”
Anyone who’s been skiing where they make artificial snow can tell the difference (when it’s first fallen). With the artificial stuff, you are spraying fine droplets in the air and they freeze as grains before they hit the ground. …or you hope they do. Sometimes it’s not quite cold enough and the grainy cover is sticky-wet too and hardens to ice. Real snow is usually a very slow accretion of microscopic bits of ice, hence the fluffy crystals that are typical pretty “snowflakes” we think of. But depending on the weather, we could get grains in precipitation also, if the drops/flakes don’t have time to grow slowly or they melt and then freeze. I’ve been in in a few windy stinging sleet storms.
Plus, if you let even fluffy snow accumulate and pack down then it can form rock-hard chunks. When you see video of people being buried in avalanches, or trees being snapped off, this is from rock-hard chunks of compressed snow, not a flood of fluffy stuff. This is also where igloos come from. When it gets like this, you can take a saw or big knife and cut bricks of it that won’t crumble. I know I’ve encountered chunks (result of using explosives for avalanche control in Whistler) where your ski-pole cannot even dent the boulder, even though it just looks like packed snow.