At the molecular level, 0°C is where water molecules slow down enough to link arms and form a crystalline structure—ice. That’s why ice is less dense than liquid water, which is why it floats. If ice sank, our lakes would freeze solid from the bottom up, and fish would become popsicles. So thank goodness for 0°C and the weirdness of hydrogen bonds.
In fact, if water didn’t have this quirky freezing point, you wouldn’t be here reading this. Ice floating on ponds insulates the water below, allowing life to survive winter. So next time you see an ice cube bobbing in your drink, give it a little salute. It’s a hero.
