But now, there's hope. By modeling the fluid and walking dynamics of the situation, and comparing the math with some real-world walking-with-coffee experiments, the UCSB scientists have uncovered a few tips for bleary-eyed coffee cup carriers.
"Of course, there are ways to control coffee spilling," study co-author Rouslan Krechetnikov told Life's Little Mysteries.
Coffee drinkers often attempt to walk quickly with their cups, as if they might manage to reach their destination before their sloshing java waves reach a critical height. This method is scientifically flawed. It turns out that the faster you walk, the closer your gait comes to the natural sloshing frequency of coffee. To avoid driving the oscillations that lead to a spillage, walk slowly. [Why Does Room-Temperature Coffee Taste So Bad?]
Secondly, watch your cup, not your feet. The researchers found that when study participants focused on their cups, the average number of steps they took before spilling coffee increased greatly. Krechetnikov and his graduate student Hans Mayer, the primary author of the study, suggested two explanations for this result: First, focusing on one's cup tends to engender slower walking, and second, it dampens the noise, or chaotic sloshing, in the cup. Whether focused carrying decreases the amount of noise because we perform "targeted suppression," automatically counteracting the sloshing of the liquid with small flicks of our wrists, or because we simply hold the cup more steadily when we're looking at it, the researchers could not say.