The Fascinating Science Behind Beer Foam

RenderSeven writes "Science has so far been at a loss to explain why tapping a beer bottle with another causes it to explosively foam over. Thanks to a grant from the Spanish Ministry of Economy and Competitiveness, a research team at the University of Madrid studying fluid mechanics has found the answer with some fascinating slow-motion video. Their soon-to-be-published paper found that tapping the bottle (or shooting it with a laser) causes a series of compression and expansion waves, that generate unstable buoyant plumes, quickly turning most of the liquid into foam. PhysicsBuzz notes that the process is very rapid and nearly unstoppable once started."

Beer and lasers.

[fahrbot-bot]

Their soon-to-be-published paper found that tapping the bottle (or shooting it with a laser) causes a series of compression and expansion waves, that generate unstable buoyant plumes, quickly turning most of the liquid into foam.

Just one more reason sharks are lousy drinking buddies.

Re:I make beer...

[jm007]

Ah... that explains it. I had become somewhat nervous about the beverages handed to me by my grade school son ever since he learned about that prank. Nothing ever happened... and I thought he was just being a good, thoughtful boy.

Re:I make beer...

[gstoddart]

This sounds like it requires further testing. The setup: 5 identical cans, 4 shaken, one left unshaken as a control.

Oh you'd need much more than that.

You need to test beer (light beer, normal beer, dark beer, American beer), sodas (clear, dark, diet, rootbeer). You could also test energy drinks.

You need to control for how cold the can and it's contents are. You could test for can size (is a tall can fizzier than a short can?). You could test the ratio of the can height to diameter. There's likely different types of pop-tops.

You might also need to determine the threshold for spontaneous can explosion where it's coming out even if you don't do anything. We'll need a paint shaker for this.

Hell, we might also need to do tests to determine if the likelihood is determined by how inconvenient it would be (critical need detectors and dress clothes).

I'm going to need a truckload of beers, sodas, a walk in fridge, a normal fridge, a bar fridge, several changes of wardrobe, two assistants, a steady supply of pizza, a lazy boy, a paint shaker, a monkey, 4K of cocaine, some LSD, several hookers, a high speed camera, a good internet connection and a really fast car.

The only thing I'm worried about is the bats. ;-)