By Rachael LallensackDec. 5, 2016 , 7:15 PM
Thanks to a tiny goggle-wearing parrot named after Obi-Wan Kenobi, scientists have shown just how much we still don’t know about animal flight. The researchers set out to illustrate a problem that’s been warned of in their field of study, but never tested: The three most popular methods used to calculate lift, or how much force winged animals use to keep their bodies soaring, are frequently inconsistent and inaccurate. To do so, they spent months training Obi to fly from perch to perch through a flattened vertical laser projected through a cylindrical lens. Sound dangerous? Don’t worry; Obi had his own custommade pair of 3D-printed goggles as safety glasses, and the lasers themselves were harmless. Why lasers? Because the team needed a way to three-dimensionally observe the vortices—think miniature air tornadoes—birds create when they flap their wings. A total of 12 high-speed cameras surrounded the 1-meter-long flight path to capture Obi’s speed, wake flow, and path of the vortices.
The scientists’ most surprising finding, published online today in Bioinspiration & Biomimetics, was that the vortices chaotically break down in the blink of an eye—literally, both take about 100 milliseconds. What they saw on video did not match what the three equations calculated. Two equations consistently underestimated the lift values. The other kept producing a zero value, which would imply free fall, at times when the footage clearly showed the bird still flapping through the air. The findings could help researchers develop better flying robots. In the meantime, Obi deserves a thank you—or perhaps an extra serving of his favorite treat: fresh broccoli.