Ball

Although many types of balls are today made from rubber, this form was unknown outside the Americas until after the voyages of Columbus.

The Spanish were the first Europeans to see the bouncing rubber balls (although solid and not inflated) which were employed most notably in the Mesoamerican ballgame.

The word came from the Middle English bal (inflected as ball-e, -es), in turn from Old Norse böllr (pronounced [bɔlːr]; compare Old Swedish baller, and Swedish boll) from Proto-Germanic ballu-z (whence probably Middle High German bal, ball-es, Middle Dutch bal), a cognate with Old High German ballo, pallo, Middle High German balle from Proto-Germanic *ballon (weak masculine), and Old High German ballâ, pallâ, Middle High German balle, Proto-Germanic *ballôn (weak feminine).

If ball- was native in Germanic, it may have been a cognate with the Latin foll-is in sense of a "thing blown up or inflated."

[4] In Homer, Nausicaa was playing at ball with her maidens when Odysseus first saw her in the land of the Phaeacians (Od.

And Halios and Laodamas performed before Alcinous and Odysseus with ball play, accompanied with dancing (Od.

[6] Among the ancient Greeks, games with balls (σφαῖραι) were regarded as a useful subsidiary to the more violent athletic exercises, as a means of keeping the body supple, and rendering it graceful, but were generally left to boys and girls.

The names in Greek for various forms, which have come down to us in such works as the Ὀνομαστικόν of Julius Pollux, imply little or nothing of such; thus, ἀπόρραξις (aporraxis) only means the putting of the ball on the ground with the open hand, οὐρανία (ourania), the flinging of the ball in the air to be caught by two or more players; φαινίνδα (phaininda) would seem to be a game of catch played by two or more, where feinting is used as a test of quickness and skill.

Due to the ideal gas law, ball pressure is a function of temperature, generally tracking ambient conditions.

The action required to apply spin to a ball is governed by the physics of angular momentum.

Spinning balls travelling through air (technically a fluid) will experience the Magnus effect, which can produce lateral deflections in addition to the normal up-down curvature induced by a combination of wind resistance and gravity.