No Use Crying Over This, Either

The Physics of Spilled Coffee

“I cannot say for sure if coffee spilling has been detrimental to scientific research to any significant extent,” says study author Rouslan Krechetnikov, a mechanical engineer at the University of California, Santa Barbara. “But it can certainly be disruptive for a train of thought.”

Krechetnikov and his graduate student Hans Mayer decided to investigate coffee spilling at a fluid dynamics conference last year when they watched overburdened participants trying to carry their drinks to and fro. They quickly realized that the physics wasn’t simple. Aside from the mechanics of human walking, which depends on a person’s age, health, and gender, there is the highly involved science of liquid sloshing, which depends on a complex interplay of accelerations, torques, and forces.

I have a vague recollection of this being studied years ago, looking at walking resonances.

However, physicist Andrzej Herczynski at Boston College thinks Krechetnikov and Mayer’s study didn’t go far enough. “I was personally a bit disappointed that the study is limited to cylindrical mugs … leaving out the very common curved or conical cups, such as those used for cappuccinos and lattes in Italy,” he says. “Still, the paper seems at minimum destined for the Ig Nobel Prize.”

The conical spill-resistant mugs were popular with my seagoing shipmates back in the day.