In this learn node the 2008 discovery of how the dolphin kicks with huge power is spotlighted at Rensselaer Polytechnic Institute where the discovery was made. For decades, scientists have puzzled over the sea mammal’s speed, since “Gray’s Paradox” was described, as the Rensselaer website explains:
There was something peculiar about dolphins that stumped prolific British zoologist Sir James Gray in 1936. He had observed the sea mammals swimming at a swift rate of more than 20 miles per hour, but his studies had concluded that the muscles of dolphins simply weren’t strong enough to support those kinds of speeds. The conundrum came to be known as “Gray’s Paradox.”
Timothy Wei, professor and acting dean of Rensselaer’s School of Engineering, has solved Gray’s Paradox using his new state-of-the-art water flow diagnostic technology that measures the force a dolphin generates with its tail. The image above is from a video that captures the action of the dolphin by using Digital Particle Image Velocimetry (DPIV). The dolphin performing in the video is Primo, who is retired from the U.S. Navy.
For background on these subjects, the San Diego Zoo has an excellent online dolphin section and the University of California Irvine School of Biological Sciences explains DPIV in great detail.