I don't know if you guys have seen the British comedy quiz show QI (brilliant show), but in episode 10 of series A (aptly called Aviation) Stephen Fry (the host) mentions that there are five leading theories of how lift is generated, but none are validated. he then goes on to say that this only affects out understanding of lift and not how we engineer wings.

Now I am aware of maybe two prevalent theories (Bernoulli's principle and Coanda Effect), what are the other three he is referring to? And would an approximate theory (or an empirically sound hypothesis) be enough to design aircrafts?

Edit: I am aware of the fact that our understanding of lift is pretty watertight. I just wanted know if there were other hypotheses that used to compete with our current theory. (They could have been proven wrong, I just wanted to know them)

  • $\begingroup$ QI is a great show but you can't believe everything on it. $\endgroup$
    – GdD
    Apr 28, 2017 at 8:25
  • 1
    $\begingroup$ At the end of the day it's entertainment, occasionally there's something said on the show that's fundamentally wrong but they get it right most of the time. $\endgroup$
    – GdD
    Apr 28, 2017 at 8:30
  • 1
    $\begingroup$ @MichaelThomas I've seen it, but personally I think that the other question contains a good brief summary of various descriptions of lift that basically are your "five theories of lift generation" $\endgroup$
    – Federico
    Apr 28, 2017 at 8:54
  • 1
    $\begingroup$ I can't find the button to accept Federico's comment as the answer. According to this question it might have gone after I edited my question. If a moderator could close this question for me that would be great! $\endgroup$ Apr 28, 2017 at 9:44
  • 2
    $\begingroup$ We leave duplicate questions up as guideposts to the duped answer. No need to delete. I don't know if the other answer says this, but more than one "theory" of lift can be true. For example, the Bernoulli concept of speed vs pressure is working at the same time as Newton's equal and opposite reaction. They're not mutually exclusive. NASA has a good series of pages on which theories are debunked. $\endgroup$
    – TomMcW
    Apr 28, 2017 at 18:55


Browse other questions tagged .