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The tennis ball theorem was first published under this name by Vladimir Arnold in 1994, [2] [3] and is often attributed to Arnold, but a closely related result appears earlier in a 1968 paper by Beniamino Segre, and the tennis ball theorem itself is a special case of a theorem in a 1977 paper by Joel L. Weiner.
The theorem was first proved by Henri Poincaré for the 2-sphere in 1885, [4] and extended to higher even dimensions in 1912 by Luitzen Egbertus Jan Brouwer. [5] The theorem has been expressed colloquially as "you can't comb a hairy ball flat without creating a cowlick" or "you can't comb the hair on a coconut". [6]
The tennis racket theorem or intermediate axis theorem, is a kinetic phenomenon of classical mechanics which describes the movement of a rigid body with three distinct principal moments of inertia. It has also been dubbed the Dzhanibekov effect , after Soviet cosmonaut Vladimir Dzhanibekov , who noticed one of the theorem's logical consequences ...
A tennis ball. Curve shortening on a sphere can be used as part of a proof of the tennis ball theorem. This theorem states that every smooth simple closed curve on the sphere that divides the sphere's surface into two equal areas (like the seam of a tennis ball) must have at least four inflection points. The proof comes from the observation ...
Tennis ball theorem; Theorem of the three geodesics; U. Uniformization theorem; V. Vermeil's theorem; W. Weinstein's neighbourhood theorem; Willmore conjecture
Tennis ball theorem; This page was last edited on 29 September 2024, at 03:06 (UTC). Text is available under the Creative Commons Attribution-ShareAlike 4.0 License ...
In table tennis, the Magnus effect is easily observed, because of the small mass and low density of the ball. An experienced player can place a wide variety of spins on the ball. Table tennis rackets usually have a surface made of rubber to give the racket maximum grip on the ball to impart a spin.
A fact from Tennis ball theorem appeared on Wikipedia's Main Page in the Did you know column on 17 June 2018 (check views).The text of the entry was as follows: Did you know... that the tennis ball theorem concerns curves that, like the seam of a tennis ball, cut the surface of a sphere into two equal areas?