ZIE Mc KEN IC MIN DO
Superheroes, Fact or Fiction? Mark Nicholson discovers how nature has turned fantasy into reality
Insect flight is far more agile than birds or aeroplanes
14 Superheroes, Fact or Fiction?
OakleyOriginals
what abilities spring to mind when someone says ‘superhero’? The ability to fly? Walking on walls? Or an uncanny talent for surviving against the odds? Although Marvel Comics have been writing far-fetched tales about characters with superhuman powers for decades, evolution has turned fiction into reality and provided us with living, breathing and indeed flying proof that it got there first. So how do animals effortlessly achieve these things that humans merely dream of? And can we replicate them? A huge number of species across the animal kingdom can fly, from buzzing midges to lumbering vultures. But not all fliers are created equal. Most birds are only able to fly forwards, and are often relatively ungainly in the air, at least as compared to their smaller brethren: the insects. Insects are often capable of flying backwards or hovering on the spot, more like a helicopter than an aeroplane, and possess a fine control over flight that many birds lack. This allows them to land on your skin without detection, or even land on water. But how do they accomplish their feats of aerial acrobatics? It turns out that insect flight is a complex phenomenon that is still poorly understood. According to some researchers, insects use at least three different
mechanisms to increase their lift beyond that predicted by simple fluid mechanics. Firstly, their wings beat at a sharp angle to horizontal, creating an effect known in aviation as stalling. In aircraft, this is disastrous, causing huge loss of lift due to separation of the air flow from the wing and often causes the plane to crash. In insects however, the act of stalling creates a vortex (think miniature whirlwind) immediately above the leading edge of the wing, which provides a large lifting force, almost as if the insect is being sucked upwards. Secondly, as their wings travel through the air, they rotate. This rotation creates an additional down-current, which helps to keep them aloft in a manner analogous to a tennis ball with backspin. Finally, in addition to creating the leading edge vortex, any wing beat will inevitably create smaller trailing edge vortices behind the wing. These usually sap energy from the flier, but insects have adapted to sweep their wings back through the turbulent air, recapturing energy that would otherwise be lost. All these mechanisms contribute to a system far more innovative than our brute-force methods of getting into the air. One complex enough that we’re unlikely to be replicating it any time soon. So perhaps insect-like flight is out of our reach, but walking on walls is a different story. Many species possess the ability to hang around obnoxiously on our ceilings and walls. Their methods may vary, but a couple of unifying themes emerge. Small insects, often flies, tend to take the rather obvious route of having sticky feet. They have tiny glands which slowly secrete an oily adhesive that literally glues them to the surface in question. Spiders have claws on their feet that hook into grooves too small for us to see (which, incidentally, is why they struggle to get out of very smooth containers such as baths and sinks). Yet clever as these two options are, the most ubiquitous and ingenious method is yet to come and proves that you don’t have to be an insect to have superhero qualities. This number is showcased by a friendly little creature: the gecko. Easter 2011