If you walk carrying an uncovered cup of coffee, it will probably spill.

To unravel the great mysteries of this phenomenon, the Pentagon gave $170,000 to researchers at the University of California, Santa Barbara. The grant was made through the Defense Advanced Research Projects Agency, whose mission is "to make pivotal investments in breakthrough technologies for national security."

In a resultant study entitled, "Walking with coffee: Why does it spill?" the scientists found that "in the walking with coffee problem the motions of the human body, while seemingly regular, are quite complex and are coupled to a coffee cup and liquid therein, which makes it difficult to unravel the precise reasons behind coffee spilling."

They ultimately determined differences like "common cup sizes, the coffee properties, and the biomechanics of walking [are] responsible for the spilling phenomenon." Bonnie Kristian