Jobs I wish I had…
Posted by Ben on March 17th, 2004
…doing research around Guinness. Researchers have shown that the bubbles actually can fall down the sides of the glass without violating laws of physics.
Using a super-slow-motion video camera — able to record 750 frames a second — Stanford University scientists with a penchant for some cold Guinness have confirmed that beer bubbles do fall.
But careful analysis of the tape has revealed that, while bubbles are lighter than beer and should rise, the laws of physics need not be rewritten after all.
“The answer turns out to be really very simple,” said Richard Zare, a professor of natural sciences at Stanford.
He said the old axiom, “What goes up, must come down,” actually holds true.
“In this case, the bubbles go up more easily in the center of the beer glass than on the sides because of the drag from the walls. As they go up, they raise the beer, and the beer has to spill back, and it does.
“It runs down the sides of the glass carrying the bubbles — particularly little bubbles — with it, downward,” Zare said.
Of course, this does involve a lot of hard work…
But Zare and postdoctoral student Andrew Alexander were skeptical, so they set out to test the theory by “analyzing” beer at both the pub and in the lab.
“Andy and I first disbelieved this and wondered if people had maybe too much Guinness to drink,” Zare said.