Richard Dawkins beautiful new book Flights and Fancy: Defying Gravity by Design and Evolution is claimed to describe:
- how nature and humans have learned to overcome the pull of gravity and take to the skies.
But Dawkins does not meet this goal since no real explanation of the physics of flight is presented. What is offered is a reference to Newton suggesting that air molecules hitting the lower surface of a wing generates upward pressure and lift, and most importantly to Bernoulli suggesting that faster air flow over the upper side of the wing generates low pressure adding to lift, but with the serious caveat:
- Exactly why the curved top of the wing causes the air to move faster is quite complicated.
- Nevertheless, the air molecules do hug the curved upper surface rather than flying off at a tangent, they do travel faster over the curved upper surface than the flatter lower surface, and the Bernoulli effect really does provide a certain amount of lift in consequence.
So Dawkins does not know how birds can fly, but he cannot be blamed because there is in the standard scientific literature no credible explanation. Only recently has the true functioning of a wing generating substantial lift at the expense of small drag been revealed, see Secret of Flight and take off to new insight!
PS Recall that the Secret of Flight is uncovered from a description of slightly viscous incompressible flow as potential flow modified by 3d rotational slip separation, which explains why the air flow hugs the upper wing surface under low pressure and separates at the trailing edge without high pressure destroying lift.
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