My students wanted me to write a post explaining why penguins can’t fly (it was THE question on one of their course quizzes).  Although I’m giving it away for any future students that may read this (I can always change the quiz), as my Thanksgiving gift to them (and Christmas and all their birthdays and any other occasion upon which I wouldn’t give them a gift anyway), here goes…

Considering the four forces of flight (thrust, drag, lift, weight), Bernoulli’s Principle (an increase in the speed of the fluid occurs simultaneously with a decrease in pressure), and Newton’s Second Law of Motion (F=ma); it is intuitively obvious why penguins cannot fly.  Let us begin with the forces of flight.  Penguins weigh a lot.  Lift must be generated to overcome that weight.  Lift is generated via relative wind across properly and appropriately designed airfoils.  Bernoulli’s Principle requires an airfoil, in this case the penguin’s wings, designed to create a pressure differential (lower on top, higher on bottom) large enough to lift the penguin.  This requires that relative wind previously mentioned.  Relative wind is generated through thrust.  Thrust must first overcome drag.  Have I mentioned that penguins weigh a lot?  Since F=ma, and taking into account the mass of a penguin and the penguins wings not being designed in such a way as to create any real lift, a force great enough to overcome said mass and accelerate it to a speed swift enough to generate the required relative wind thereby creating the needed pressure differential, and thus lift, is impossible for a penguin to achieve.

Of great note to many of them – I did not ONCE mention water.

>>> The day is just beginning, the night and my cigar are a distant thought – but ’til next time… Happy Thanksgiving to all!