By now, we all know the struggle that goes along with trying to carry a bunch of drinks to the table.
But have you noticed that it’s a lot easier to walk with multiple glasses of beer than it is to walk with many cups of coffee?
Emilie Dressaire, an assistant professor of Mechanical and Aerospace Engineering at Princeton University, led a research team to quantify this observation.
According to a release from the NYU Polytechnic School of Engineering, the group used a high-speed camera, a moving stage, and their three selected fluids (Guinness, Heineken, and coffee) to record their observations.
The researchers found that the foam on beer reduces sloshing, as we’ve all probably observed on our own.
But interestingly, the researchers also found that foam is very efficient at damping waves. It doesn’t take a lot of foam, either—just a few layers of bubbles do the trick.
What happens is this: the foam rubs against the walls of your glass or other container as waves in the liquid travel, which expends a lot of energy. That effectively slows down drink sloshing due to viscous dissipation.
The team presented their findings at the 67th Annual Meeting of the American Physical Society’s Division of Fluid Dynamics (APS-DFD) held this month in San Francisco.
If you’re wondering why researchers would spend so much time on beer, Dressaire has a great answer:
“There are different ways to approach a scientific or technological question, and it’s good to keep an open mind, because interesting ideas can come from the most familiar observations.
Students are great at connecting their everyday life to some of the most difficult problems. To this point, their work has serious and promising applications in numerous industrial applications, such as the transport of liquid as cargo.”
We’ll toast to that—but carefully, if we’re wielding java.
We’d also like to see an experiment comparing latte foam with coffee stout foam in the future, just to be sure.