It doesn't solve the mystery of why we're here or even explain "why do birds suddenly appear, every time you are near," but researchers say they have unlocked how "helicopter seeds" work.
Maple seeds, familiar in yards throughout Central New York, twirl as they fall.
That slows their descent, said scientists at California Institute of Technology who have published a paper explaining for the first time "the aerodynamic secret of the enchanting swirling seeds."
Caltech Prof. Michael H. Dickinson and David Lentink, a professor at Wageningen University in the Netherlands, found that the leading edge of a spinning seed creates a tornado-like vortex. That lowers the air pressure across the seed's "wing," drawing it upward against gravity's downward tug.
"The use of leading-edge vortex to increase lift is remarkably similar to the trick employed by insects, bats and hummingbirds when they sweep their wings back and forth to hover," Caltech said in a release.
The scientist found the vortex by creating a model of a maple seed, immersing it in a tank of clear oil to which they added tiny glass beads. Lasers were used to illuminate a layer of beads, creating a strobe-like effect that shows the tiny swirl of air that helps maple seeds twirl gently through the air, helping the trees spread more widely across the landscape.
On another matter, experts in Carpentry report the appearance of birds is because "just like me, they long to be close to you."
Contact Charles McChesney at firstname.lastname@example.org.