Be Careful! Your Coffee Is More Likely To Spill Than Your Latte

It's not exactly science that coffee is more likely to spill than a latte. Why? Well, because lattes have more foam. Coffee does not. However, findings published in the journal Physics of Fluid go in depth about why that is.

"While I was studying for my Ph.D. in the south of France, we were in a pub, and we noticed that when we were carrying a pint of Guinness, which is a very foamy beer, the sloshing almost didn't happen at all," Alban Sauret, one of the researchers from New York University Polytechnic School of Engineering, said in a news release.

Researchers at Princeton University have ground down the fluidity of this phenomenon. Here's what they did: the researchers filled a glass container with water, glycerol and dish soap, making the liquids more viscous in the lab. Then, they created uniform layers of tiny bubbles into liquid.

They injected air at a constant flow rate through a needle located at the bottom of the container, creating uniform layers of 3-millimeter-diameter bubbles. Then, they experimented with jolting the apparatus with a quick, side-to-side motion of rocking it steadily back and forth and recording the results.

The researchers observed that a few layers of the foam were enough to decrease the wave height by a factor of 10. The study authors believe that friction dissipates the energy of the sloshing liquid through the sides of the container.

With future studies, this may help in developing cheap and easy ways to transporting large amounts of liquid. Coffee or a latte anyone?