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Jellyfish Propulsion

November 11, 2015

Jellyfish swim the opposite way of how we assumed.

Transcript

Aurelia_aurita_Luc_Viatour

Aurelia aurita jellyfish. (Luc Viatour /www.lucnix.be/CC BY-SA 3.0)

BOB HIRSHON (host):

Propulsion lessons from jellyfish. I’m Bob Hirshon and this is Science Update.

Jellyfish are among the most efficient swimmers, but how do they do it? Stanford University bioengineer John Dabiri says that’s a tough question to answer.

JOHN DABIRI (Stanford University):

The challenge with water in particular is that it’s transparent, so actually seeing how the water moves can be a challenge. And so we need something in the flow that we can visually track.

HIRSHON:

In the journal Nature Communications, Dabiri describes how he floated tiny glass beads in a tank of water and let jellyfish swim through them. Lasers tracked the beads’ movement, indicating the displacement of the water. They revealed that instead of pushing against the water, the way a submarine does, jellyfish pull the water towards them. It flows around their body and propels them forward. Dabiri says underwater vehicles might increase their efficiency by copying the sea creatures’ technique. I’m Bob Hirshon, for AAAS, the science society.