Falling cat problem

Several explanations have been proposed for this phenomenon since the late 19th century: The falling cat problem has elicited interest from scientists including George Gabriel Stokes, James Clerk Maxwell, and Étienne-Jules Marey.

[6] The article's summary in Nature appeared thus: M. Marey thinks that it is the inertia of its own mass that the cat uses to right itself.

The torsion couple which produces the action of the muscles of the vertebra acts at first on the forelegs which have a very small motion of inertia on account of the front feet being foreshortened and pressed against the neck.

The hind legs, however, being stretched out and almost perpendicular to the axis of the body, possesses a moment of inertia which opposes motion in the opposite direction to that which the torsion couple tends to produce.

In the second phase of the action, the attitude of the feet is reversed, and it is the inertia of the forepart that furnishes a fulcrum for the rotation of the rear.Despite the publication of the images, many physicists at the time maintained that the cat was still "cheating" by using the handler's hand from its starting position to right itself, as the cat's motion would otherwise seem to imply a rigid body acquiring angular momentum.

A falling cat modeled as two independently rotating parts turns around while maintaining zero net angular momentum
Falling Cat – images which appeared in the journal Nature in 1894, captured by a chronophotographic gun, a device of Marey's own invention. The editor of Nature wrote, "The expression of offended dignity shown by the cat at the end of the first series indicates a want of interest in scientific investigation."