Question

Hi Michi,
I feel a need to share with you something connected to physics, and also to something related to psychology and neuroscience.
Maybe I already told you that ever since I entered the halls of physics, and especially the wing of aerodynamics, I’ve been witnessing a puzzling phenomenon: airplanes have been flying for over 100 years, and yet there is still no consensus about the force that enables them to fly. Right now I’m focusing only on creatures and machines from the size of a small bird and up, because insects fly due to other physical phenomena!
My inexhaustible chutzpah led me to drive the scientists in the Faculty of Aeronautical Engineering at the Technion crazy already some 37 years ago.
I had certain theories about flight. And lo and behold—every few years the explanation for flight would change!
One of the explanations the scientists were fond of was the vortices created in certain regions around the wing, and that these are what produce lift.
In any case, most scientists argue that lift must be a reaction to downward vertical momentum. I must admit that it dawned on me too late to tell my interlocutors—people with whom I argued with fear and trembling, as befitted their elevated status as academics, while I was nothing but a farmer [pretty ignorant!]—that according to the law of conservation of energy, it cannot be that work is invested twice for the same action.
If I submerge an empty sealed bottle in water—whether in a small tank or in the ocean—by applying vertical pressure to the bottle, the moment I stop applying pressure, the bottle will leap upward, because I already invested the work beforehand in pushing the bottle under, and now it jumps up [according to Archimedes’ principle!]
In short—more than 30 years ago, I carried out countless experiments to prove my claim that lift is a result of Bernoulli’s law: I shaped a cardboard wing profile, and added to it at the back a flap that rises backward at a moderate angle. I would ride a bicycle with the model hanging by strings from a light rig I had built and held in my hand. This wing was held at an angle of attack of 0, and nevertheless the wing rose!
Are you familiar with the phenomenon that when you hold a spoon vertically alongside a stream of water, so that the curve of the spoon lightly touches the stream, the spoon is “sucked” into the stream? I attributed this phenomenon to Bernoulli’s law, but my opponents argued that the horizontal movement of the spoon into the water stream is the result of the reaction to the water flowing down along the spoon, and the moment it falls off it has a horizontal component in the opposite direction. I tried to refute their claim, and I fashioned from a thin sheet of metal a flat surface with a curve in the middle. When I held this sheet vertically, parallel to a vertical jet of water, and the water “kissed” the sheet, the sheet was “sucked” into the stream—even though the water flowed straight downward, clinging to the sheet, and provided no basis whatsoever for any horizontal momentum!…
It didn’t help me, and I couldn’t change the minds of those scientists [including some from abroad!], even though sometimes I would read an article in which a claim exactly like mine was raised.
Since the development of the propulsion method I’m working on is based solely on pressure differentials, I tend to present my idea to aeronautical engineers, and they do not dismiss the feasibility of my idea—even though it contains no mention of action-reaction.
When I demonstrated my claim by means of a tiny wing onto which I blew air from my lungs before my friend/partner Prof. Tanhum Weller, he reacted and said, what’s the wonder in that, and showed me the textbook he had studied from about 50 years ago, in which lift is indeed explained according to Bernoulli’s law.
But afterward I went and presented this phenomenon to Moti [who is a highly experienced engineer in flow dynamics], and he claimed that perhaps something was flawed in the experiment.
And he devoted a lot of time to explaining the matter of the vortices to me.
We both agreed that if a piece of wool were attached behind the wing, and it tilted backward and downward while the wing was rising, that would be an appropriate indication that the lift was created due to vertical momentum.
In short—I built a small wind tunnel in which I could easily prove my claims. It seems to me that I succeeded in doing so. Except that this tunnel, which I built with my meager abilities [with my two left hands…], is very far from meeting strict scientific criteria. In other words, my wind tunnel needs to be very precise in order to prevent some other side factor from influencing the tests. Well, that’s already a bit beyond me. And so I don’t dare rely on these experiments in my arguments with the aerodynamics people at the Technion. Maybe, maybe, maybe I’ll manage to scrounge up some small wind tunnel in civil engineering.
But one more thing—I mentioned the matter of vortices. Many times aerodynamicists tend to explain lift by the existence of vortices.
I would always nod politely and wonder to myself where on earth it is written that a vortex is supposed to create lift.
Until I watched several videos in which you can see an airplane taking off and there really are vortices around the wingtips. In other words, the vortices are a fact. Does this fact have the power to explain how the vortex causes lift?!
And then I remembered that in my youth I read a book describing the development of medical science, and it claimed that in the Middle Ages doctors believed that the healing of wounds had to be accompanied by the secretion of pus.
Why? Because that’s what they knew, and so they were pleased when pus appeared. There are probably more examples. True, in that period medicine was not yet based on orderly scientific thinking as is accepted today. Even so, I claim that not infrequently, thinking that pretends to be scientific can also lead us into absurd and completely illogical territory. In this context—yesterday I read a fascinating article about the study materials of the Nazi regime, which purported to be science-based… Chilling—to put it mildly!
To conclude—I hope I was careful not to draw the target around the point of impact.
So I wish you and all your family a good week