A ball is a round, usually spherical but sometimes ovoid, object with various uses. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used for simpler activities, such as catch, marbles and juggling. Balls made from hard-wearing materials are used in engineering applications to provide very low friction bearings, known as ball bearings. Black powder weapons use stone and metal balls as projectiles.
Read more about Ball.
Some articles on ball:
... it is possible to obtain k copies of a ball in the Euclidean n-space from one, for any integers n ≥ 3 and k ≥ 1, i.e ... a ball can be cut into k pieces so that each of them is equidecomposable to a ball of the same size as the original ... These results then extend to the unit ball deprived of the origin ...
... yields a paradoxical decomposition of the solid unit ball minus the point at the ball's centre (this center point needs a bit more care, see below) ... However, there are only countably many such points, and like the point at the centre of the ball, it is possible to patch the proof to account for them all ...
... is a theorem in set-theoretic geometry which states the following Given a solid ball in 3‑dimensional space, there exists a decomposition of the ball into a finite number of non-overlapping ... two identical copies of the original ball ... of the theorem implies that given any two "reasonable" solid objects (such as a small ball and a huge ball), either one can be reassembled into the other ...
... seam is the tiny seam which runs around a cricket ball at 90 degrees to the large, raised seam ... in order to create conventional swing when the ball is relatively new, more recently, an understanding has evolved that the quarter seam can be lifted on one side, presumably with the thumb or ... Lifting the quarter seam during an over alters the balance of air pressure surrounding the ball as it travels through the air and help it reverse ...
... Computed tomography of a football (soccer) (Video) Baoding balls Baseball Basketball Billiard balls Bowling ball (and pin) Lacrosse ball Cricket ball Golf ball next to a hole ...
More definitions of "ball":
- (noun): One of the two male reproductive glands that produce spermatozoa and secrete androgens.
Synonyms: testis, testicle, orchis, ballock, bollock, nut, egg
- (noun): A ball game played with a bat and ball between two teams of 9 players; teams take turns at bat trying to score run.
Example: "There was a desire for National League ball in the area"; "play ball!"
Synonyms: baseball, baseball game
- (noun): A solid ball shot by a musket.
Example: "They had to carry a ramrod as well as powder and ball"
Synonyms: musket ball
- (noun): A lavish formal dance.
- (noun): A pitch that is not in the strike zone.
Example: "He threw nine straight balls before the manager yanked him"
- (noun): A spherical object used as a plaything.
Example: "He played with his rubber ball in the bathtub"
- (noun): Round object that is hit or thrown or kicked in games.
Example: "The ball travelled 90 mph on his serve"; "the mayor threw out the first ball"; "the ball rolled into the corner pocket"
- (noun): A compact mass.
Example: "A ball of mud caught him on the shoulder"
Synonyms: clod, glob, lump, clump, chunk
- (verb): Form into a ball by winding or rolling.
Example: "Ball wool"
- (noun): A more or less rounded anatomical body or mass; ball of the human foot or ball at the base of the thumb.
Example: "He stood on the balls of his feet"
- (noun): The people assembled at a lavish formal dance.
Example: "The ball was already emptying out before the fire alarm sounded"
Famous quotes containing the word ball:
“Knowing what you can not do is more important than knowing what you can do. In fact, thats good taste.”
—Lucille Ball (19111989)
“Throw down the ball, ye Jews daughter,
Throw down the ball to me!
Never a bit, says the Jews daughter,
Till up to me come ye.”
—Unknown. Hugh of Lincoln (l. 1316)
“It may be possible to do without dancing entirely. Instances have been known of young people passing many, many months successively, without being at any ball of any description, and no material injury accrue either to body or mind; Mbut when a beginning is madewhen felicities of rapid motion have once been, though slightly, feltit must be a very heavy set that does not ask for more.”
—Jane Austen (17751817)