A physics principle that states t' pressure exerted by air perpendicular t' its direction o' travel decreases with an increase in velocity. This be t' theoretical principle upon which airplane wings work. An airplane wing's airfoil is unsymmetrical, its upper surface havin' a greater curve than its lower surface. This causes air flowin' across t' upper portion o' t' win' t' speed up, since it must cross a greater surface area in t' same length o' time. T' increase in air velocity on t' upper surface causes t' air pressure in t' region just above t' win' t' be reduced. Avast, me proud beauty! T' higher pressure below t' win' presses upward on it, creatin' lift.