JF Ptak Science Books Quick Post
- Source: Etienne Marey, "Des mouvements que certains animaux exeutent pour retomber sur leurs pieds, quand ils sont precipites d'un lieu eleve", in Comptes Rendus de l'Academie des Sciences, vol CXIX, 1894, p. 714. (This paper is reproduced a few weeks later in the more popular science journal La Nature on 10 November 1894.)
Aha!
This is the famous falling/dropped/thrown cat experiment in which Marey shows that when dropped with its back towards the ground a cat will respond and right itself via muscular reaction to land on its feet, all of the time. It was not a trick of “air pressure” or other such thing which Marey dismissed, as once the action of the fall is slowed so that the whole of the activity can be intelligently observed, and it was by the animal's movement alone that brings it to land on its feet. It is Marey's instrumentation that takes the day, using a camera capable of making 60 images per second, which was a huge advance over his chronophotographic gun of 1882 which made 12 images/second. Marey remarks that this animal action is true in other animals, giving the examples of rabbit and dog.
Marey is a rather stiff writer and takes his time to explain himself in extended detail—this isn't an entertaining story though the results are of course fantastic.
That piece of needling aside, Marey is one of my favorite 19th century science figures. He worked across numerous fields, though I think his great importance is in the invisible-to-visible part--that he was able to make was were essentially moving pictures of complex and/or fast action, displaying motion in shockingly easy manner. His work opened as much of a new and surprising world as that of Lippershey/Galileo and Co. with the telescope and Janssen/Leeuwenhoek/ and the others with the microscope.
For further reading see G. Gbur's Falling Felines and Fundamental Physics, Yale, 2009.
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