(04:53) Well, it turns out that the very simple body shape of these jellies, the simple umbrella, it creates what are called vortex rings. Think of a doughnut of swirling water. So each time the animal contracts its muscles, it creates this doughnut of water. And it almost pushes off of that doughnut of swirling water to move through the water without having to use a lot of energy in the process. So it’s a very different swimming stroke than what you or I would try to accomplish in the ocean, but it’s quite effective.
My comment actually a fish’s body is doing this in good part as well. Same with seals and walruses…the muscles flush in and out to push the water along the body.
When a car is aero dynamic it meets a starting point for this but without the follow through of a body’s motion in and out along the surface area.
PF
That is freakin’ magnificent Thanks!
david fb
One of the points that they discuss toward the end of the podcast is that the propulsion may be a secondary effect of the jelly’s pulsing umbrella vortices. The primary purpose may be that the vortices bring food in to the jelly’s tentacles.
That is interesting because the more complex life still has the intestines opening to end of a worm. The car still puts energy out the back on the tires and tailpipe.
Motion needs to move away from waste. Food in and waste out. I get the jelly fish keeps the two within range but the motion moves the waste out and food in.
Yep forgot all about that. I had heard it years ago. The singular opening is no surprise. The shape and motion more importantly the age of the species gives it away.