The act is colloquially referred to as “beer tapping”: Someone hits a beer bottle on the head, often with the bottom of their own bottle, and within seconds the victim of the prank is left with a small amount of flat beer and a bottle dripping with foamy bubbles of carbon dioxide.
Javier Rodríguez-Rodríguez, assistant professor at the Fluid Mechanics Group of Carlos III University of Madrid and lead author of an abstract about the research, and his colleagues were at a bar discussing the process behind this phenomenon when they realized they did not fully understand it. And according to their unsuccessful search for a solution online and through scientific databases, neither did anyone else.
Honestly, I've never had this happen to me. But I guess if you're going to do research, you might as well do beer research. Hopefully, they wasted factory beer, not beer that would have been better put to use by consuming it.