Bug hacks physics with "butt flickers" to launch pee at 40 G's
We’re willing to bet you’ve never given much thought to how bugs urinate, but even if you did you probably wouldn’t imagine them using butt-based pinball paddles to flick drops of pee at 40 G’s, using physics never before seen in nature.
The glassy-winged sharpshooter is the insect that gets the gold for golden showers, in both volume – it pees up to 300 times its own body weight every day – and speed, flicking away droplets faster than the human eye can see. And, it turns out, you don’t get to be number one in “number ones” without some weird physics hacks.
Scientists at Georgia Tech studied the prolific pissers using high-speed video and microscopy to find out exactly what was going on. The bug is adorned with an anal appendage that the researchers dub a “butt flicker,” and once it’s shaken the dew off the lily this flicker pulls back and launches the droplet at high speed. The team measured the acceleration at over 40 G’s.
“We realized that this insect had effectively evolved a spring and lever like a catapult and that it could use those tools to hurl droplets of pee repeatedly at high accelerations,” said Elio Challita, co-author of the study.
But these whizzing whizzes get even weirder. When the team measured the airspeed of these anal expulsions, they found that they were traveling 1.4 times faster than the butt flicker that fired them. That suggests the bugs make use of a physics principle called superpropulsion, which has previously only been seen in synthetic systems.
If you’ve ever double-bounced someone on a trampoline and launched them way higher – that’s superpropulsion. In this case, the sharpshooters are actually matching the frequency of their butt flickers to the frequency of the pee droplets to get the most efficient launch.
It may seem like an elaborate way to take a leak, but the researchers found that it’s the most energy efficient method for their lifestyle. Sharpshooters only eat sap from xylem plants, which has basically zero nutrients, meaning they have to drink – and pee – pretty much non-stop.
So what’s the point of knowing the bathroom habits of bugs? The team says that we could apply some of these wee wonders to our own technology, such as using speaker vibrations to flick water off a watch.
“What the sharpshooters are dealing with would be like us trying to fling away a beachball-sized globe of maple syrup that was stuck to our hand,” said Miriam Ashley-Ross, program director at the National Science Foundation. “The efficient method these tiny insects have evolved to solve the problem may lead to bio-inspired solutions for removing solvents in micro-manufacturing applications like electronics or shedding water rapidly from structurally complex surfaces.”
The research was published in the journal Nature Communications. You can watch the high-speed watersports, if that's your thing, in the video below.
Source: Georgia Tech