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Re: What is biomechanics? (or, The Truth About Flying Snakes - Was: Re: science and philosophy)
Jaime A. Headden wrote:
> It is a feather in action that does
> anything, and not just a single feather, but a arrangement.
What about the tip feathers in birds of intermediate aspect ratio, where
feathers act individually to increase the effective aspect ratio, modulate the
tip vortex, and provide thrust?
> And this is a parachuting animal, right? I mean, just because it's called a
> flying snake, surely
> no-one was seriously suggesting that it moved through the air by lift-based
> powered flight?
Doesn't that sort of depend upon the shape and path of the vortices above its
> I do not support *Longisquama* flying by any
> present data. Or even gliding. So far, no study shows what appear to be
> radiating slats could even produce a sustained drag
Is this a presumption about type of lift produced, if any?
> <And paragliders do the same thing. It's not gliding in the sense of a
> glider 'plane, or a soaring bird,
But is, in the sense of a gliding Concorde or other aircraft with low-aspect
> but surely most animals that get called
> 'gliders' - flying frogs, flying squirrels, sugargliders, for example -
> are really parachutists of some description (with varying ability to control
> their descent)?
I wouldn't say 'surely', unless I had looked at the shape of the vortices
produced during their flight. Has anyone done that yet for all three of these
> The only 'glider' that might be closer to a glider 'plane
> that I can think of offhand is _Draco_.>
> I know of some references that have drawn differences in animals that
> glad versus parachute, and the snake and frog are both considered
Gliding snakes remind me a lot of the fuselage lift mechanisms produced by
dirigibles. Do they you?
> The distinction has been to support with anatomy a direction-based
> definition, above or below 45 degrees.
I've not ever looked to see -- is this a distinction favored by biologists, or
defined by aerodynamicists? What specific and sudden change in airflow occurs
at a descent slope of 100%?
All the best,