Looking up something about analog computers, ran into this NASA publication on the history of fly-by-wire. The really interesting part of the book is NOT the computing part; it’s the basic history of flying with wings.
Each profession and skill has its own internal history and base assumptions, which are rarely understood by outsiders.
Sometimes this external ignorance is cultivated by the insiders who want to keep their priesthood intact. Tenure belongs to this category. Inside academia the failures and sins of tenure and grants and peer review have been well known for decades. Outsiders still believe the weird myth of “free debate and inquiry,” which academic insiders love to spread.
Sometimes the internal experience just isn’t taught or explained because the insiders don’t think it needs to be discussed. The basic concept of flying belongs in this category. Outsiders believe that airplanes go up because of Bernoulli and the airfoil effect. Insiders know that’s not true!
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Finally, in the early years of the 1800s, the Englishman George Cayley figured out that a rigid plane moving through the air generates lift, and the world changed. For the remainder of the century the problem shifted to the need to provide sufficient airflow over planar “wings” to generate enough lift to balance the weight of the aircraft. Even a flat surface gives the lifting effect if sufficient forward speed is applied. As some wags used to say about stocky jet fighters, “Even a brick can fly if you hang a big enough engine on it.”
As work progressed, researchers found out that making the wing flat on the bottom and curved on the top helped generate more lift with less thrust. This is the shape of airplane wings today. The differences in the thickness of the wing are a function of the forward thrust: more thrust, thinner wings. This is why jets have thinner wings than piston-driven airplanes.
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In speech science we constantly use airfoils as an analogy for the closing action of the larynx. Faster flow means less air molecules pushing on each surface at each moment, so the net outward force on the folds is less.
Applying this revelation, Bernoulli is also a secondary or even irrelevant factor for the larynx. Most of the push and pull happens because of the SHAPE of the folds and the component vectors of the air pressure, just like the wing that rises because of its ANGLE, not its curve. When the folds are closed, the pressure below builds up for a moment, and the force is pushing both up and out.. After this initial pulse pops the folds open, there’s no excess pressure pushing the folds both up and out, so the constant muscle tension can bring the folds back together. If Bernoulli is involved, it’s a small effect.
The rest of the NASA book is about control of the aircraft, with another inside revelation. Contrary to external belief, the Wright brothers weren’t solving the airfoil problem because it wasn’t a problem! They were solving the problem of controlling the aircraft for stable flight. As bike makers they started with the INTERNAL UNDERSTANDING that a naturally unstable device is more maneuverable, so their first planes relied on intensive control of all the moving parts by the pilot. Later efforts had to de-bike the concept to achieve longer and steadier flights without fatigue, and then to allow radio or mechanical autopilots.
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See also: Life works by altering the impedance on both sides of a boundary.
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