A team of engineers and biologists recently revealed that jellyfish pull rather than push their way through the water.
It has long been believed that the pulsations jellyfish make as they swim were acting to push off the water behind them to move forward. But a collaboration between Stanford engineers and Woods Hole biologists has found otherwise. Instead, it seems that jellyfish create pockets of low pressure behind their "heads" and so higher pressure water in front of them rushes around them to equal things out and in the process, they are propelled forward. The scientists found the same thing to be true for lamprey eels.
The way they figured this out is pretty freaking cool. It's almost impossible to accurately calculate the rate of flow and the pressure exerted by each individual water molecule around the jellyfish (or lamprey) because the number of molecules is astronomical. However, by adding "proxy molecules" to the water in the form of tiny glass beads, they could measure the flow rate and pressure of the beads and thereby infer the same for the water molecules. Add some lasers and some high-speed cameras and they could track the motion of every bead and its affect on the surrounding beads as the jellyfish and lamprey subjects swam through the tank.
I love science.
Here's some more geek from the week:
- In Australia, sheepdogs are on the front line of the battle between penguins and foxes.
- Sciences have found that a small number of animal species don't get cancer.
- Biologist Joan Strassmann has built her scientific career on watching wasps. [#longread, WITH VIDEO]
- Artist Kaycie D. has created a character for every element of the period table.
- Bouncing water droplets are kind-of adorable. [VIDEO]
- Who knew robots could be so hilarious when doing exactly what you told them to do. [WITH VIDEO]
- The Babylab in London studies, you guessed it, babies. More specifically though, their brains. [#longread]
- Do you know how many pictures of you might be out there in the digital world?
- One day your heartbeat might replace all your passwords.
- How to prepare a camera for a spacewalk.
- Hyperspace explained in less than two minutes. And... GO! [VIDEO]
- Check out this gorgeous new graphic of over 500 exoplanets arranged by temperature and density. Be sure to zoom in!
Keep on geeking!
@Summer_Ash, In-house Astrophysicist