Here's Professor Painlevé lecturing the class on why rabbits don't grow to the size of elephants and why, despite some engineering calculations, bigger animals are faster than smaller ones.
It's one of at least three short films he did for the Palais de Decourverte at this time, so he's in his dry, lecture mode, with his sense of humor only occasionally and very drily evident, as in such issues as how to stick a rock to a dewdrop. Neither does he ever explain anything, but he never does in any of his movies I have seen; he just shows how and leaves the why to metaphysicians.
Even so, the lack is more evident here, because this is the real world he's discussing, a world of elephants and rabbits and steam engines and men and glasses being filled. It's not enough to know how. Why would be nice. Why, however, is not the subject of science. That's what metaphysicians are for, if they are for anything.
