What was a fact taught to you in school that has been proven false during your lifetime?

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How planes generate lift.
- What doesn't help is that plane pilots are basically taught a different version of physics to spare them from liquid dynamics and to see the forces on an aerofoil as independent ones which makes it all pretty confusing for a layperson trying to get a basic understanding of both and marry the two
- Did they finally find that out? Last time I checked even PhDs in aerospace engineering still added "we think" at the end of their explanations.
  
  It is known yeah. Another user commented it. If you take a wing and put it in a wind tunnel you can put sensors in its wake to measure the pressure. By manipulating the fluid flow you can change the pressure. So low pressure on top and high pressure on bottom. Multiply that by the surface area and you get a force. Smaller force on top of the wing, lower force on the bottom of the wing. So the wing goes up. Of course theres some physics going on in the fluid that explains the change in pressure, but this is just a quick and simply-put explanation because I took a fat amount of zquil and am tired.
  Source: Im getting a PhD in aerospace engineering
  Edit: I had to do this in a wind tunnel during one of my undergrad courses. It was fun playing with the wind tunnels, would recommend
  
  hm, I just read through a few publications pertaining the Navier–Stokes equations and the scientific community still didn't seem to find out why they're not 100% accurate even in lab conditions because of threedimensional interference, is that correct?
  
  The wing experiment with hundreds of pressure sensors shows lower pressure on top and more on bottom.
  
  NASA has a webpage on aeronautics that says lift is the mechanical force created by a solid object turning a flow of liquid or gas. They also have an equation for calculating lift for any solid object/fluid combo.

219 comments