Everyone knew that beer tapping — the "classic jerk move" in which you slam the bottom of your beer bottle onto the neck of someone else's — makes you an asshole. But up until now, no one knew quite why tapping turned your Miller High Life into a pants-ruining Mount Doom.
Science has the answer: According to recent findings from physicist Javier Rodriguez Rodriguez, the mystery of the physics behind beer tapping has finally been explained.
According to Rodriguez, while mysteries like what makes a good, fluffy head on a draft beer and why bubbles in Guinness sink have been explained, scientists never really knew what was happening inside a beer during a dick move. In a series of controlled experiments inspired by one of his colleagues being outsmarted at a bar, they found that a sharp tap to the neck of a beer bottle actually sets off a series of miniature explosions creating mushroom clouds similar to that of an atomic bomb.
Wait, really? Yes, you're basically giving your bro's beer a puke nuke. Here's the stages of what Rodriguez discovered (all images courtesy of the scientist himself via NPR):
1. The strike sends waves reverberating throughout the liquid in the bottle. Tiny bubbles in the beer are disturbed and pulsate, shrinking and growing.
Rodriguez says the bottle acts like a spring and sends a "sound wave" through the beer.
2. The bubbles can't take your friend's crap anymore and collapse violently, breaking up into clouds of tiny bubbles.
3. Now your bottle is filled with tiny bubbles - bubbles which have much greater surface area and so which absorb the carbon dioxide (carbonation) from the beer.
The bubbles grow rapidly and start to move to the surface of your brew.
4. "The faster the bubbles rise, the faster they grow, because the mixing with carbon dioxide is more efficient." In other words, the bubbles grow exponentially and shoot out the mouth of your bottle.
And there you have it.
Rodriguez says that his research has other potential applications, such as preventing carbon dioxide eruptions from lakes and volcanoes. But in the meantime, he's mostly just finally provided the answer to the mystery behind one of drinking's douchiest tricks.