Engineers help discover the surprising trick jellyfish use to swim

A Stanford-led team shows how these ancient creatures' undulating motions cause water to pull them along. This counterintuitive insight could spur new designs for energy-efficient underwater craft. By Tom Abate Video of a lamprey (black outline) swimming in a water tank. Colors indicate low-pressure suction forces (blue) and high-pressure pushing forces (red) generated by the animal as it swims. Colorbar indicates pressure in units of Pascals (Newtons per square meter). Playback is approximately 1/60 of real time. Millions of years ago, even before the continents had settled into place, jellyfish were already swimming the oceans with the same pulsing motions we observe today.