Which is correct related to lift: Bernoulli's theory or Newton's theory? I was trying to find out how exactly is lift generated. I came across Bernoulli's theory and Newton's theory. But I no where found which one is correct. Can someone help me out with this?
 A: To enlarge slightly upon Ben51's comment (which serves as an answer in itself) there are several different mathematical formalisms which have been developed over the years to account for the generation of lift by a cambered wing moving through the air. There is the idea of integrating a pressure distribution over the top and bottom areas of a wing and expressing lift as the difference between them, the idea of tipping the momentum vector of a parcel of air downwards as it passes by the wing and expressing the lift as the vertical component of the reaction force exerted on the wing by the air parcels, the idea of circulation of airflow about the span axis, and vortex sheet-shedding at the trailing edge.
Physicists will use the method which yields the most elegant answer and furnishes the most useful insights into the process. Engineers will use whichever formalism yields the particular answer they seek in its most convenient form with the least amount of work.
A: Typically, the Bernoulli explanation is taught incorrectly. If taught correctly, it is just an alternative to the Newton explanation. The incorrect Bernoulli explanation says parcels of air separated at the leading edge are reunited at the trailing edge. Wrong. Air parcels along the upper part get to the trailing edge long before those on the lower part. The result is a vortex directing flow downward. The shape of the wing is only an optimization for aircraft that mostly fly upright.
Some aircraft have symmetrical wings because they are designed to fly inverted as well as upright.
Either way, they get lift by adjusting the angle of attack, by pitching the entire aircraft up or down.
