Бильярд доптары және олардың түрлері

Ball used in cue sports

A billiard ball is a small, hard ball used in cue sports, such as carom billiards, pool, and snooker. The number, type, diameter, color, and pattern of the balls differ depending upon the specific game being played. Various particular ball properties such as hardness, friction coefficient, and resilience are important to accuracy.

Various other games have their own variants of billiard balls. English billiards uses the same number of balls as carom billiards, but the same size as snooker balls, as the game is played on the same size table as snooker. Each player uses a separate cue ball, with modern English billiards sets using one white ball with red spots and the other being yellow with red spots. Russian pyramid uses a set of fifteen numbered white balls and a red or yellow cue ball that are even larger than carom billiards balls at Kaisa has the same pocket and ball dimensions but uses only five balls: one yellow, two red and two white cue balls, one for each player. Bumper pool requires four white and four red object balls, and two special balls, one red with a white spot and the other white with red spot; all are usually in diameter. Bar billiards uses six or seven white balls (depending on regional variations) and one red ball in diameter.

There is a market for specialty cue balls and even entire ball sets, featuring sports team logos, cartoon characters, animal pelt patterns, or other non standard decorations. Entrepreneurial inventors also supply a variety of novelty billiard games with unique rules and balls, some with playing card markings, others with stars and stripes, and yet others in sets of more than thirty balls in several suits. Marbled looking and glittery materials are also popular for home tables. There are even blacklight sets for playing in near dark. There are also practical joke cue and 8 balls, with off center weights in them that make their paths curve and wobble. Miniature sets in various sizes (typically 2/3 or 1/2 of normal size) are also commonly available, primarily intended for undersized toy tables. Even an egg shaped ball has been patented and marketed under such names as Bobble Ball and Tag Ball.

The 8 ball is frequently used in Western, especially American, culture as an element of T shirt designs, album covers and names, tattoos, household goods like paperweights and cigarette lighters, belt buckles, etc. A classic toy is the Magic 8 Ball "oracle". The term "8 ball" is also slang both for of cocaine or crystal meth, and for a bottle of Olde English 800 malt liquor. It has also been used to refer to African Americans, particularly those of darker skin tones, as in the film Full Metal Jacket. The expression "behind the eight [ball]" is used to indicate a dilemma from which it is difficult to extricate oneself. The term derives from the game kelly pool. Because the collisions between billiard balls are nearly elastic, and the balls roll on a surface that produces low rolling friction, their behavior is often used to illustrate Newton's laws of motion. Idealized, frictionless billiard balls are a staple of mathematical theorems and physics models, and figure in dynamical billiards, scattering theory, Lissajous knots, billiard ball computing, and reversible cellular automata, Polchinski's paradox, contact dynamics, collision detection, the illumination problem, atomic ultracooling, quantum mirages, and elsewhere in these fields. "Billiard balls" or "pool balls" is the name given to balls used in stage magic tricks, especially the classic "multiplying billiard balls". Though obviously derived from real billiard balls, today they are usually smaller, for easier manipulation and hiding, but not so small and light that they are difficult to juggle, as the magic and juggling disciplines have often overlapped since their successful combination by pioneers like Paul Vandy. The phrase "as smooth as a billiard ball" is sometimes applied to describe a bald person, and the term "cue ball" is also slang for someone who sports a shaved head. An urban legend received cultural attention to many saying, "If the Earth were the size of a billiard ball, it would be smoother". It was used by Discover magazine in 2008, stating no diameter variations measuring +/ should be detectable, but mistook the diameter tolerance for smoothness. If the Earth were reduced to the size of a billiard ball, its mountains and trenches would equal the texture of 320 grit sandpaper and the variation in diameter would be , which is near the maximum diameter tolerance.

—Billiard ball c. 1865
—Billiard ball c. 1868
—Billiard ball c. 1869
—Billiard ball c. 1871