Foam Physics Prevents Beer Spills

Alban Sauret at Princeton University noticed one day that when people would carry a beer away from a bar it wouldn't spill (provided it wasn't full to the brim. Who knows how he decided to investigate why coffee spills out of his mug, but his latte didn't (provided they were filled to the same level). Maybe, like me, he has a lot of coffee stained shirts and pants.

It turns out the foam dampens the sloshing motion of beer and latte. Since there's no foam on regular coffee, it sloshes much easier.

This study actually has some real world implications. Putting a foam on top of a liquid in a tanker truck, for instance, could make the load more stable.

Isn't science fun?