A test pilot reported that the craft waddled around in the air like “a pregnant duck.” Much later, in 1954, Einstein himself called his excursion into aeronautics a “youthful folly.” The individual who gave us radically new theories that penetrated both the smallest and the largest components of the universe nonetheless failed to make a positive contribution to the understanding of lift or to come up with a practical airfoil design. Make sure that what you’re providing is pure hair, without any rubber bands, and free of dirt, pins, leaves or anything else that could damage the machines that sort the hair for use, Gautier says. In 1916 Einstein published a short piece in the journal Die Naturwissenschaften entitled “Elementary Theory of Water Waves and of Flight,” which sought to explain what accounted for the carrying capacity of the wings of flying machines and soaring birds. In 1917, on the basis of his theory, Einstein designed an airfoil that later came to be known as a cat’s-back wing because of its resemblance to the humped back of a stretching cat.

The solutions of those equations and the output of the CFD simulations yield pressure-distribution predictions, airflow patterns and quantitative results that are the basis for today’s highly advanced aircraft designs. Air has mass, and from Newton’s third law it follows that the wing’s downward push results in an equal and opposite push back upward, which is lift. The forces at work are also familiar from ordinary experience-for example, when you stick your hand out of a moving car and tilt it upward, the air is deflected downward, and your hand rises. It might be natural to think that when a wing’s curvature displaces air upward, that air is compressed, resulting in increased pressure atop the wing. These assumptions also made the underlying mathematics simpler and more straightforward than they otherwise would have been, but that simplicity came at a price: however successful the accounts of airfoils moving in ideal gases might be mathematically, they remained defective empirically. Einstein then proceeded to give an explanation that assumed an incompressible, frictionless fluid-that is, an ideal fluid. Still, they do not by themselves give a physical, qualitative explanation of lift.

Virtually all jet-powered aircraft have an air brake or, in the case of most airliners, lift spoilers that also act as air brakes. Moreover, aircraft with symmetrical airfoils, with equal curvature on the top and bottom-or even with flat top and bottom surfaces-are also capable of flying inverted, so long as the airfoil meets the oncoming wind at an appropriate angle of attack. This seems to be a bar counter with a small, sunken basin in the top. It is only when an airplane lands and comes to a halt that the region of lower pressure atop the wing disappears, returns to ambient pressure, and becomes the same at both top and bottom. To take advantage of these pressure differences, Einstein proposed an airfoil with a bulge on top such that the shape would increase airflow velocity above the bulge and thus decrease pressure there as well. Without mentioning Bernoulli by name, he gave an account that is consistent with Bernoulli’s principle by saying that fluid pressure is greater where its velocity is slower, and vice versa.

The page rises, supposedly illustrating the Bernoulli effect. Neither Bernoulli nor Newton was consciously trying to explain what holds aircraft up, of course, because they lived long before the actual development of mechanical flight. He brought the design to aircraft manufacturer LVG (Luftverkehrsgesellschaft) in Berlin, which built a new flying machine around it. Contemporary scientific approaches to aircraft design are the province of computational fluid dynamics (CFD) simulations and the so-called Navier-Stokes equations, which take full account of the actual viscosity of real air. McLean, who spent most of his professional career as an engineer at Boeing Commercial Airplanes, where he specialized in CFD code development, published his new ideas in the 2012 text Understanding Aerodynamics: Arguing from the Real Physics. The professional firm always gets the permit after meeting all kinds of standards set by the state in which they are operating. On October 26, 1979, Ken Fraser set the ultimate benchmark in sport fishing by landing a world record bluefin tuna off the coast of Nova Scotia, Canada. Coast Guard has yet to suffer a fatality in the water, but swimmers have dealt with broken bones, damaged spines and other serious injuries.