The In-Depth Science of Why a Beer Bottle Erupts When You Whack It

Beer physics lesson of the day:

“Beer tapping” is the kind of jerky thing that jerks do at bars. They walk up to you—you with your nice, cold bottle of beer, the one you’ve been looking forward to all day while you were working at your hard, stressful job—and they thump their bottle down on yours. Your beer erupts in a foamy mess. You can try to catch some of that quickly disappearing beer, if you want. But, really, it’s gone.

But then, when you’re done being annoyed, you think: Why did my beer do that?

The answer, it turns out, is super complicated, and has to do with the physics of small bubbles and the power of a reflecting pressure front.

More at Smithsonian, via GeekPress.