If you’re a person who exists, you’ve heard the urban legend
that bumblebees shouldn’t be able to fly. Ignore the empirical evidence
presented by thine eyes, plebe, for almighty Science declares that bumblebee
flight defies the laws of physics! Those scientists, always with their laws and
theories! When will they ever learn!
As you may have guessed, bumblebee flight does not defy the
laws of physics. No one is quite sure how this urban legend got started, but its
proponents insist that it was birthed
from the mind of either a mathematician or an engineer at a party in the 1930s.
That this unnamed but truly hard-hitting scientist was probably drunk at the
time is conveniently left out of the stories.
Seriously, though, some accounts do attempt to name the
scientists responsible for starting the rumor that bumblebee flight is a physical
impossibility. The rumor has been pinned on German aerodynamicist
Ludwig Prandtl, who lived from 1875 to 1953 and taught at the University of
Gottingen. Others blame Swiss aeronautical engineer Jakob Ackeret.
A perhaps more credible theory is that the assertion first
appeared in French
entomologist Antoine Magnan’s 1934 book, The Flight of Insects. Magnan referenced calculations supposedly
made by French mathematician André Sainte-Lague when he made the
assertion that the flight of insects – not just bumblebees, but insects in
general – should be scientifically impossible. No one knows how bumblebees,
specifically, got stuck with the burden of impossible flight, but perhaps it’s
just a natural consequence of being so fat and derpy and having such tiny, tiny
wings.
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| "Derp." Bumblebee in flight by Pahazzard from Wikimedia Commons. |
However, Saint-Lague made at least one crucial mistake on
the way to concluding that bees can’t fly – he based his calculations on the
principles of fixed-wing
aerodynamics, which you may recognize as the science of airplane flight.
Bumblebees are not planes. Of course, if bumblebees were planes – with rigid,
smooth, fixed wings – they wouldn’t be able to fly. Their bodies would be too
big and they wouldn’t be able to generate enough lift.
But bumblebees aren’t planes, and they don’t have rigid, fixed
wings. Their wings are flexible. Bumblebees don’t glide; they obviously flap
their wings. But how does a bumblebee generate enough lift to take flight and
stay aloft? Bumblebees’ wings aren’t long enough to generate adequate lift by
flapping up and down, the way birds’ wings do. Instead, bumblebees flap their
wings back and forth, in a
horizontal figure-of-eight motion. That motion creates vortices, described as tiny
hurricanes, above the bee’s wings. Because the air pressure is lower in
these vortices than in the surrounding air, the bee is able to stay aloft.
How did scientists figure this out? In one experiment,
Chinese researcher Lijang Zeng of Tsinghua University and his team strapped
tiny mirrors onto bumblebees and then fired lasers at them. I
am not even making this up. Somehow, this allowed the scientists to create
precise models of natural bee flight that were more accurate than those created
in previous experiments, for which scientists were forced to use tethered bees.
Tethered bees apparently don’t fly right, for some reason.
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| I'll leave it up to you to imagine how they attached the tethers to the bees. |
