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So, on the other day me and my colleges were discussing the following phenomena:

Pick two open bottles of beer. With the bottom of the first, hit the second on the bottleneck, in the following way: you align then vertically, and hit the first on the second from the top.

The typical event is that the second bottle starts to spit all the gas, almost completely emptying it.

Our hypotheses was that the way the bottle was hit, the eigenmodes of the bottle were excited. This eigenmodes caused a compression/extension on the beer itself, causing it to segregate from the liquid. However, we were not sure if this is the right explanation for it.

Can someone confirm this reasoning or have another suggestion to explain this phenomena?

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@RonMaimon It is not duplicate: in this case the bottom of the bottle does not break. Maybe the the explanation is the same, but the phenomenon differs. – J. C. Leitão Jan 17 '13 at 9:03
2 (Why does a beer bottle foam up after a sudden impact on its mouth?) – Joe Apr 1 '14 at 18:54

Briefly, a cavitation is created at the bottom of the beer bottle which pulls the carbondioxide out of solution and in conjunction with a propogating pressure wave the gas is released out the top of the bottle taking a bunch of beer with it.

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Can you please explain in more detail? "Briefly" was not enough for me to understand. – J. C. Leitão Jan 17 '13 at 9:04

There was a recent publication addressing exactly this question.

From the abstract:

Here, we show that the overall foaming-over process can be divided into three stages where different physical phenomena take place in different time scales: namely, the bubble-collapse (or cavitation) stage, the diffusion-driven stage, and the buoyancy-driven stage.

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