
This article appeared in the
"Editor's File"
in The Textbook Letter, Volume 12, Number 2.
The relevant principle for this event is called
Bernoulli's principle:
When air flows rapidly across a surface,
the air pressure on the surface is reduced.
This is the basic principle of flight.
Wrong! The flight of a balloon depends on the principle of buoyancy, and the flight of an insect, a bird, a bat or an airplane depends on the principle of action-and-reaction -- i.e., on Newton's third law. Pearson's writers have merely parroted a bogus notion that has appeared in schoolbooks for decades. (See "On Wings of Ignorance" in The Textbook Letter, Vol. 10, No. 5.)
The cover of Methods for Teaching Science as Inquiry has a picture of a dragonfly, and the same picture recurs in the body of the book. Have Pearson's writers ever seen a dragonfly in flight? If so, have these "inquiry" experts ever asked themselves why a dragonfly must beat its wings to stay aloft?
William J. Bennetta is a professional editor, a fellow of the California Academy of Sciences, the president of The Textbook League, and the editor of The Textbook Letter. He writes often about the propagation of quackery, false "science" and false "history" in schoolbooks.
