Two Spanish scientists are having something of a Holmesian moment. Javier Ruiz and Angélica Torices of Madrid's Complutense University have created an equation that determines an individual's walking or running speed based solely on their footprints.
The scientists collected data on speed and stride length from professional athletes as well as 14 paleontology students who were asked to run along a beach. Their resulting calculations showed surprising accuracy, with a margin of error ranging from 10 to 15 percent.
Now they hope to apply the equation to fossilized footprints of early humans. In fact, they have already used it on Pleistocene-era tracks in Australia. Scientists had previously guessed that the tracks indicated a speed comparable to that of a professional athlete. Ruiz and Torices' equation has estimated a much more believable sprinting pace. Mystery solved.