|
more articles like this
Helicopter Seeds
updated: May 19, 2012, 9:30 AM
By David Powdrell
As adolescent kids growing up in rustic Carson City, Nevada, my three brothers and I spent countless
hours tossing helicopter seeds into the air, marveling at their slow descent back to earth. Simple
pleasures on hot summer days.
On occasion, we'd put an ant onto the helicopter seed, lob skyward, then ponder and laugh at what the
flight might have been like for the ant. Do ants get dizzy and do their legs get wobbly when
scampering away post-flight?
Recently, my 23-year-old daughter and I came upon a lone maple tree loaded with helicopter seeds.
While waiting for her new "used" car to be detailed at the dealership, we tossed helicopter seeds and
laughed and marveled together.
I put a few of the seeds in my pocket with hopes of photographing them in flight and to do some
fundamental research on the aerodynamics of helicopter seeds. Here's a little of what I learned:
The maple tree seeds twirl and descend slowly so that they can be carried aloft by the wind and
dispersed over great distances. The mystery to scientists, however, is just how do the seeds manage to
fall so slowly?
Scientists at the California Institute of Technology and Wageningen University in the Netherlands
describe the secret in a research paper. In essence, the helicopter seeds generate a tornado-like vortex
that sits atop the front leading edge of the seeds as they spin slowly to the ground. This leading-edge
vortex lowers the air pressure over the upper surface of the seed, effectively sucking the wing upward to
oppose gravity, giving it a boost.
This use of a 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. The finding means that
plants and animals have converged evolutionarily on an identical aerodynamic solution for improving
their flight performance. Source: www.greenwavelength.com/maple-seeds-and-animals-exploit-the-
same-trick-to-fly/
Clearly, I'm no scientist but am wondering if there might be others that can expound on the subject.
I'm looking forward to seeing my brothers this summer. I'll bring along a pocketful of helicopter seeds
for a stroll down memory lane.
Send this picture as a postcard
# # # #
Send this picture as a postcard
# # # #
Send this picture as a postcard
# # # #
Send this picture as a postcard
# # # #
4 comments on this article. Read/Add
# # # #
|
