Why does blowing on your hot drink cool it down? (Synopsis) [Starts With A Bang]

“I like cappuccino, actually. But even a bad cup of coffee is better than no coffee at all.” -David Lynch

Particularly in the dead of winter, most of us enjoy a hot drink, whether it’s coffee, tea, hot chocolate or soup. But if that drink is too hot, your options for cooling it down are unsatisfying: wait for the room to cool it, which takes forever, drop an ice cube in, which waters down your drink, or blow on it.

While blowing on your drink may seem ineffective, as the breath inside your body is generally warmer than the ambient air, there’s an additional feature that makes blowing on it totally worth it: the circulation and exposure-to-air of the hot fluid vastly increases the rate of evaporation, taking the highest-kinetic-energy molecules out of the equation and cooling your drink more quickly.

Go read the physics behind why blowing on your hot drink actually does cool it down faster!