Snow Globe Physics

Every year, when decorating our house for Christmas, my aunt would bring out a snow globe that contained a miniature replica of the New York City skyline. This little tchotchke would trigger my OCD, which tends to look for patterns and order in almost everything I see. Shaking the globe would cause me to follow a single snowflake as it fell from the sky at the top of the dome onto the streets of Manhattan below. When I would lose track of it—which was most of the time—I would give the globe another shake and start over again.

I always assumed this obsession was a personal quirk, my own bit of strangeness that prevented me from enjoying the simplicity of a snow globe the way every normal human being can. As it turns out, snowflake tracking is more common than I thought. Some physicists, chemists, and meteorologists do it all the time. They are just looking for something different than I was and what they discovered is far more useful and certainly more profound.

It turns out there is an interesting natural phenomenon happening inside snow globes that no one would ever notice unless you are paying close attention. You see, when a globe is shaken, its glitter particles get dispersed throughout the liquid, moving as a random haze in different directions and at different speeds. Eventually, they slow down and begin their descent to the bottom. Life in the snow globe returns to normal, and equilibrium is restored.

But that is only what happens at a macro level. If you watch each snowflake more closely, something far more nuanced occurs. Generally, a single, isolated particle—a snowflake—will fall through the fluid faster and settle on the bottom sooner than the rest of the snow cloud. What snow globe scientists discovered, however, is that if the snowflake particles interact with one another via strong, attractive forces, then they will win the equilibrium race. In other words, by bonding together, they reach a calm, settled state faster than the single particles that go it alone.

Snow globe physics offers a good reminder: when your world is turned upside down, and everything you know is scattered into bits and pieces— by the death of a loved one, a breakup, the loss of a job, or the devastation caused by a natural disaster or viral pandemic—getting back to normal, back to equilibrium, will happen much quicker when you can build strong bonds with those around you instead of trying to deal with the chaos on your own.