Cross-disciplinary co-operation in the sciences can lead to striking results (it occurred beautifully between mathematics and computer science late last year). In this instance, The Atlantic covers a breakthrough in our understanding of jellyfish locomotion, made by a mechanical engineer.
John Dabiri and his team injected dye into the water around a moon jelly as it swam. Like Gandalf’s smoke rings, the jellies created rings of water behind them, moving down their tentacles as they swam.
The team later showed that the moon jellyfish actually produces two vortex rings for every beat of its bell. While the first one travels backwards, a second one rolls back into the bell itself, speeding up as it goes, and sucking water into the center of the jellyfish. This allows the animal to recapture some of the energy it spends on each swimming “stroke,” and pick up speed even when it’s making no effort. For that reason, the moon jellyfish is the most efficient swimmer in the ocean.
Read the full article here – highly recommended.
