Technology has made hovering possible for years. Yet despite its widespread use – in the military, competitive racing, and mass-transit – there is still something wholly surreal about a still object that floats, somehow, in midair.
New research published in the Physical Review of Letters by a team of scientists at New York University now makes hovering seem even more counterintuitive. Inspired by hovering insects, their study suggests that objects tend to hover better when they are top-heavy.
Needless to say, these findings are wildly counterintuitive. Most modern vehicles are designed with the opposite idea in mind. After all, it would be strange, not to mention frightening, to be near, say, a top-heavy eighteen-wheeler. That the opposite is true for hovering, the research suggests, has to do with how insects and birds move their wings.
In fact, these animals tend to perplex engineers. Historical attempts at airplanes with flapping wings were laughably unsuccessful. The NYU team designed a simple experiment to figure out how various fauna manage to hover so well. They placed a series of paper pyramids in a wind tunnel that vented an oscillating column of air to mimic the flapping of wings. They changed the weight distribution – from bottom-heavy to top-heavy – by affixing weights to the bottom or top of the pyramids and captured this process on high-speed video to analyze the airflow.
It is perhaps not surprising that these results demonstrated the complex yet effective way bugs and birds hover. People have had only a few decades to develop and hone hovering technology. Nature has had millions.
Some news outlets have taken this research to suggest that we'll all be hovering to and fro, like Marty McFly on his hoverboard. For instance, the French Tribune's headline read, "Hovercraft to Be Made Reality" and the State Column's read "Study: Hovering aircraft could become commonplace."
Of course, hovering vehicles are already pervasive, from helicopters to hovercraft, both of which can support tons of weight. There's also the Harrier jump jet, which hovers by using its hot exhaust to lift itself vertically off the ground. And there are even more exotic – yet still widely used – hovering vehicles, such as the maglev train, which uses magnets to float the train cars a few inches above the rails.
If technology were ever developed from the new discovery at NYU, it would probably be unlike any of these, as this study is a result of biomimetics – a branch of science that looks directly to nature for its cues on engineering and design. Biomimetic research has been fruitful before. Scientists have studied the sonic navigation of fruit bats to enhance night-vision technology. Others have modeled versatile climbing robots after the gecko. On a more domestic level, the Swiss engineer George de Mestral was inspired by the ever-stubborn bur to design a material nearly all of us have used: velcro. These ideas, as well as this new study at NYU, express the humbling and awe-inspiring idea that human technology is still no match for the designs of nature.