Ever wondered what would happen if a bubble was exposed to -40 degree temperatures? Okay, maybe you haven’t wondered, because it’s exactly what you’d think: it freezes. But the bubble takes on some interesting properties along the way.
First, notice the cross-like pattern of the expanding ice crystals, which almost resemble tiny conifer trees. At first the patches of growing ice appear as small spots on the bubble, equally dispersed. As they grow and join together, they form an ice layer without popping the bubble. But this stability won’t last. The crystalline structure of ice means that the bubble is no longer air tight, and air begins to escape.
While it would be nice to end up with a beautiful ice bubble, it’s not meant to be. As the air inside escapes through the porous ice, the newly acquired ice shell is not strong enough to maintain the bubble’s shape.
You can try this yourself next time it’s cold outside. You’ll have an easier time if you have access to an unheated sheltered area like the person who made the video, so that wind isn’t a factor.
If you’d like to see more interesting videos of how water behaves, check out this slow-motion video of a water balloon bursting.