Why does a beer bottle foam up after a sudden impact on its mouth

Movie for the APS, DFD Gallery of Fluid Motion 2013. From the paper Why does a beer bottle foam up after a sudden impact on its mouth , by Javier RodríguezRodríguez, Almudena Casado, Daniel Fuster (Submitted on 14 Oct 2013) Abstract: A sudden vertical impact on the mouth of a beer bottle generates a compression wave that propagates through the glass towards the bottom. When this wave reaches the base of the bottle, it is transmitted to the liquid as an expansion wave tha