Why Does Your Foil Actually Fly
In 1997 I earned a degree in physics from the University at Buffalo. Since then I've spent 3 decades studying physics and biophysics recreationally. I'm not a scientist, but I am very curious, and I have a passion for learning about nature. Guys like Marks, Pollack, Peclet, Feynman, Kilmov, and Kelvin have been of particular interest to me with regard to foiling and wind sports.
As a physics student we learned that airplanes, and our hydrofoils, fly mostly because of Bernoulli's Principle and angle of attack. Bernoulli's basically says that when a fluid moves faster (or when an object moves through a fluid faster) the pressure is less. So, if a foil is curved on top and flat on the bottom then the water has to move faster on the curved top part of the foil and thus the pressure will be less on top of the foil than the bottom. The foil will rise because of this difference in pressure. Well, I think that's a bunch of bullshit. Airplanes fly upside down too. According to Bernoulli's principle they should plummet to the ground if upside down. Plus, it still doesn't give us any idea of what the actual force really is that is keeping the foil up. There are only four forces in the universe: the strong nuclear force, the weak nuclear force, the electromagnetic force, and the gravitational force. Bernoulli's principle doesn't give us any clue as to which of those forces is actually at play. Common sense would have us think that it's probably not gravity that makes a foil fly because gravity does the opposite....it pulls it down. It's also probably not the strong or weak nuclear force because those are forces acting within the nucleus of atoms, not between foils and water. So, maybe it has something to do with electricity or magnetism.
The angle of attack idea basically says that the lift equation is the result of the angle between a wing and the fluid through which it is travelling which pushes on atoms that repel each other due to the electromagnetic force. Again, I think this is bullshit. And so did Marks, Pollack, Peclet, Feynman, Kilmov, and Kelvin. Why? Because there is too much drag. The mathematical equations work fine to design macroscopic objects like airplanes, but the underlying physics is not wrong. Kind of like Newton's gravity which also worked fine for macroscopic objects but failed when Einstein and others challenged it. The fundamental physics was simply wrong.
As a physics student we learned that airplanes, and our hydrofoils, fly mostly because of Bernoulli's Principle and angle of attack. Bernoulli's basically says that when a fluid moves faster (or when an object moves through a fluid faster) the pressure is less. So, if a foil is curved on top and flat on the bottom then the water has to move faster on the curved top part of the foil and thus the pressure will be less on top of the foil than the bottom. The foil will rise because of this difference in pressure. Well, I think that's a bunch of bullshit. Airplanes fly upside down too. According to Bernoulli's principle they should plummet to the ground if upside down. Plus, it still doesn't give us any idea of what the actual force really is that is keeping the foil up. There are only four forces in the universe: the strong nuclear force, the weak nuclear force, the electromagnetic force, and the gravitational force. Bernoulli's principle doesn't give us any clue as to which of those forces is actually at play. Common sense would have us think that it's probably not gravity that makes a foil fly because gravity does the opposite....it pulls it down. It's also probably not the strong or weak nuclear force because those are forces acting within the nucleus of atoms, not between foils and water. So, maybe it has something to do with electricity or magnetism.
The angle of attack idea basically says that the lift equation is the result of the angle between a wing and the fluid through which it is travelling which pushes on atoms that repel each other due to the electromagnetic force. Again, I think this is bullshit. And so did Marks, Pollack, Peclet, Feynman, Kilmov, and Kelvin. Why? Because there is too much drag. The mathematical equations work fine to design macroscopic objects like airplanes, but the underlying physics is not wrong. Kind of like Newton's gravity which also worked fine for macroscopic objects but failed when Einstein and others challenged it. The fundamental physics was simply wrong.
It turns out that the real answer for flight is electricity. Yep, your foil flies electrically. Specifically, triboelectricity. What is triboelectricity? Some materials, like air and water, have a very high ability to acquire positive charge. Other materials, like metal and prepreg carbon, have a high ability to acquire negative charge. And the separation of these positive and negative charges happens through friction. You know the effect of rubbing a balloon on your head. Air has a very high ability to acquire positive charge, so when you rub a balloon on your head the friction separates charge, and the air gets the positive charge while the balloon gets the negative charge. Now think of the massive friction of a metal airplane wing moving through air at 400mph. The air acquires massive positive charge while the metal wing of the airplane acquires negative charge. Metal is good at acquiring negative charge, while air is good at acquiring positive charge. The Earth is also negatively charged, so the plane flies because the negative electric charge of the Earth is repelling the negative electric charge of the airplane wing. Remember from eighth science class that like charges repel each other. Water also has a very high ability to acquire positive charge, while your carbon foil wing has a high ability to acquire negative charge. The negative charge of your foil then repels the negative charge of Earth.
Now you might thinking that electric charge cannot be that powerful. Well you're wrong. Richard Feynman, arguably the greatest physicist of the 20th century, proved this. He proved it through a simple thought experiment that has been verified through real measurements. Imagine two people. You remove 1% of the electrons (negative charge) from each person. Just 1%. Now each person has a net positive charge since you removed electrons, so the two people will repel each. You lay one person on the ground, and you put the other person on top of them. They will repel each other. How much weight would you have to put on top of the top person to keep him 1 meter apart from the bottom person without him being pushed up into the air? The answer is a weight equal to the weight of Earth. That is the enormous strength of electrical repulsion. The electromagnetic force is 10^36 times stronger than the gravitational force. It's the second most powerful force in the universe. That's why your foil really flys. Electric force.
People will refute this by noting that the electric force is governed by the inverse square law meaning that an airplane at 30,000 feet has a very, very small repelling electric force from the Earth. But they fail to realize that the gravitational force equation is exactly the same as the electric force equation which means that as the electric force decreases with the inverse square of distance from the Earth's surface so does the gravitational force. Exactly the same amount of decrease. So it doesn't matter how far away an airplane is from Earth because the gravitational force decreases by the exact same amount.
Now think about how spiders can fly over the ocean, how electric lifters fly, how clouds fly (which weigh millions of pounds, even billions), why rain falls faster than gravity can pull it. It's electric repulsion/attraction. It this exists for objects without wings then it obviously exists for objects with wings.
People will refute this by noting that the electric force is governed by the inverse square law meaning that an airplane at 30,000 feet has a very, very small repelling electric force from the Earth. But they fail to realize that the gravitational force equation is exactly the same as the electric force equation which means that as the electric force decreases with the inverse square of distance from the Earth's surface so does the gravitational force. Exactly the same amount of decrease. So it doesn't matter how far away an airplane is from Earth because the gravitational force decreases by the exact same amount.
Now think about how spiders can fly over the ocean, how electric lifters fly, how clouds fly (which weigh millions of pounds, even billions), why rain falls faster than gravity can pull it. It's electric repulsion/attraction. It this exists for objects without wings then it obviously exists for objects with wings.
So your sail, or your hand-wing, or your kite, or a tow line from a boat, or your paddle, or a wave, or a Foil Drive motor, or your leg pumping action, is giving you enough friction between the foil and the water to generate enough negative charge on the foil wing to repel the negative electric field of the Earth and this gives you lift. That's the real reason your foil flies. Forget Bernoulli's principle. Forget angle of attack. Universities still teach Bernoulli's principle and angle of attack, but they never tell you what the actual force really is. It's electric force. The aerospace industry still uses the mathematical equations of Bernoulli's principle and angle of attack, which work just fine for practical macroscopic objects, but they are in denial that other forces are the real answer. They're making too much money to switch their thinking.
