Which would you think are more efficient in the air? Planes or such creatures as bats, insects, and birds? Believe it or not, the plane is no match for these small wonders of nature, who “have outstanding capabilities to remain airborne through wind gusts, rain, and snow,” says Wei Shyy, professor of aerospace engineering at the University of Michigan.* Their secret? Wings that flap—the envy of aviators since man’s attempts at flying first got off the ground.
Consider: While some birds and insects are in flight, their wings are constantly changing shape to adapt to the environment. This enables them to hover and to perform sharp maneuvers. The magazine Science News reports what has been observed in bats: “When flying at slow speeds, about 1.5 meters per second, the bats turned their wingtips upside down and quickly flicked them backward during an upstroke. Scientists [have] surmised that this trick . . . provides lift and thrust.”
To be sure, there is still much to learn about natural fliers. “Physically, what are they doing to the air to produce such efficient lift?” asks Peter Ifju, professor of mechanical and aerospace engineering at the University of Florida. He adds: “There are all kinds of flow physics we just don’t understand. We can see what [birds and insects are] doing, but we don’t understand how that interacts with the air.”
What do you think? Did the versatile wing of natural fliers come about by chance? Or was it designed?