From the brilliant post THE WONDROUS MATHEMATICS OF WINTER in The New Yorker blog, by Gregory Buck:

There’s the snowman: the human form given in three spheres. It is a sort of absurdist abstraction: the top sphere makes sense, and we can stretch to consider the middle one to have captured the salient properties of those of us with more orbic midsections. But I don’t know what to make of the bottom sphere. There may be some work to do here, which Euclid or Archimedes might have gotten to if it had snowed more often in Greece. The ratios of the spheres matter. A stack of three equally sized white spheres might read as tennis balls in a sleeve or cocktail onions on a toothpick.

After considerable investigation, I have discovered that if the proportions of the diameters are 5:4:2.5 (from bottom to top) then the form unambiguously reads as a snowman, with or without carrot, coal, sticks, scarf, or hat.We have then a stack of three white spheres that signify archetypal “winter” quite clearly.I challenge you to signify any other time of year with such simple geometry.

Read more, including including Gregory Buck’s musings on how winter is the Platonist’s season, and why being a mathematician is like being stuck in a blizzard.