- What is a vortex, or vortex ring? What do vortices have to do with how a jelly moves? Read the middle section of the Nat Geo News article (“A Diaphanous Design”) for some clues. Our explorer, Kakani Katija, also gives a great explanation in this video—watch it from about 1:35 to 2:55.
- A vortex ring is “a region where the fluid mostly spins around an imaginary axis line that forms a closed loop.” Katija gives a better explanation: “How many of you have flushed a toilet? Basically, if you just take that whirlpool of fluid and . . . you take the starting end, and the finishing end, and you attach [them] to each other, that is a vortex ring.”
- What do vortex rings have to do with how a jelly moves? Katija continues: “All animals, when they swim, they generate these vortex rings.” The Nat Geo News article sums it all up: “The animal contracts its umbrella-shaped bell, squeezing out water behind it and creating a doughnut-shaped ring of water called a vortex.”
- Jellies create vortex rings as they propel themselves through the water. Why can’t we see the vortex rings created by the drone, the way we can see them so beautifully in the video from Kakani Katija? What fluid does the drone move through?
- We can only see the vortex rings in the video because researchers have injected the bell of the jelly with milk. The white milk shows up perfectly in the black-and-white footage of the swimming jelly.
- The drone is “swimming” in air. We can’t see its vortex rings because air is basically colorless. Check out this page to see airy vortex rings made visible by smoke, steam, volcanic ash, or other particles in the air.
- The engineer who designed the jelly-drone was not inspired by nature. “[I]t wasn’t until the applied mathematician built his drone that he realized it moved remarkably like a jellyfish,” according to the Nat Geo News article. However, engineers are inspired by natural patterns, phenomena, and processes all the time! The process of using the natural world as a guide to develop new technology is called biomimicry. Biomimicry has inspired scientists engineers to experiment with creating a self-lighting Christmas tree and “green cement” using processes found in coral reefs. Consult “Ask Nature,” the fantastic site from the Biomimicry Institute. In what ways are scientists and engineers inspired by jellies?
- It looks like there are three ongoing projects based on properties of jellies. One idea is to study the “gel” in jellies to create strong, protective materials for underwater structures and personal flotation devices.
- Another idea is to investigate the gel in jellies and their relatives, sea anemones, to create elastic structures for deep-sea oil and gas rigs.
- The final idea would study the way light is reflected by cilia found in comb jellies (which are related to true jellies), and apply this to outdoor and indoor color light displays.