It is testament to the great esteem with which Jacob Bernoulli and his kin were held in 18th century Europe, that every science book or lecture that touches in the least way upon aerodynamics today, makes central mention of their observations on the almighty airfoil as the explanation of flight. The fact that most airplanes still fly pretty darn upside down should give current efforts at building human powered machines pause to look beyond rotating airfoils and propellers as the key means of their propulsion.