Billiard ball

's celluloid ball patent (1871) Early balls were made of various materials, including wood and clay (the latter remaining in use well into the 20th century). Although affordable ox-bone balls were in common use in Europe, elephant ivory was favored since at least 1627 until the early 20th century; the earliest known written reference to ivory billiard balls is in the 1588 inventory of Thomas Howard, 4th Duke of Norfolk. Dyed and numbered balls appeared around the early 1770s. It is unclear if the cash prize was ever awarded, and there is no evidence suggesting he did in fact win it. However, Hyatt's composite had problems. One of the most relevant is cellulose nitrate flammability, not because of making the billiard balls explode, as is often claimed, but because of the dangers of handling it in its pure form during manufacturing. Another problem was related to camphor mass exploitation, leading to the devastation of Taiwan's forests and displacement of indigenous communities. Subsequently, the industry experimented with various other synthetic materials for billiard balls such as Bakelite, acrylic, and other plastic compounds. The exacting requirements of the billiard ball are met today with balls cast from plastic materials that are strongly resistant to cracking and chipping. Currently Saluc, under the brand name Aramith and other private labels, manufactures phenolic resin balls. Other plastics and resins such as polyester (similar to those used for bowling balls) and clear acrylic are also used. Ivory balls remained in use in artistic billiards competition until the late 20th century. ==Types==

Carom billiards In the realm of carom billiards games, three balls are used to play most games on pocketless billiards tables. Carom balls are not numbered, and are 61–61.5 mm (approximately in) in diameter, and a weight ranging between with a typical weight of . They are typically colored as follows: • White: for the first player • Yellow: cue ball for the second player (historically this was white with a distinguishing spot) • Red: the Four-ball billiards uses an extra object ball, usually blue. English billiards 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 and the other being yellow with red spots, with some versions sporting both balls red spots. The object ball used is red, with some versions sporting white spots. Pool Pool balls are used to play various pool games, such as eight-ball, nine-ball, and straight pool. These balls, the most widely used throughout the world, are smaller than carom billiards balls, and larger than those for snooker. According to World Pool-Billiard Association equipment specifications, the diameter is , plus or minus with between with a. The balls are numbered and colored as in the table show here. Balls 1 through 7 are the of and 9 through 15 are the . The 8 ball is not considered part of either suit. Striped balls were introduced around 1889. The yellow-and-red sets are sometimes referred to as "casino sets" as they were developed to make identification of suits easier for spectators at eight-ball championships often held in casinos. Snooker sets are also available with considerably smaller-than-regulation balls (and even with ten instead of fifteen reds) for play on smaller tables (down to half-size), and are sanctioned for use in some amateur leagues. Sets for American snooker are typically , with numbered colour balls. The set of eight colours used for snooker balls (including white) are thought to be derived from croquet, which uses the same set of colors. Snooker was invented in 1884 by British Army officers stationed in India. Croquet reached its peak popularity at the same time, particularly among people in the same social context. There are many other similarities between croquet and snooker, which when taken together, suggest that the derivation of the latter owes much to the existence of the former. Some snooker variations use extra balls: • Snooker plus - uses an orange ball with a value of 8 points and a purple ball with a value of 10 points. • Power Snooker - uses a white ball with red stripe (similar to the 11 ball in Pool) which doubles all the ball values for 30 seconds. • Tenball - uses a yellow ball with black cross with a value of 10 points. • Riyadh Season snooker - uses a gold ball with a value of 20 points. Other games Various other games have their own variants of billiard balls. Russian pyramid uses a set of fifteen numbered white balls and a maroon, 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 circle and the other white with a red circle; all are usually in diameter. Bar billiards uses six or seven white balls (depending on regional variations) and one red ball in diameter. Novelty balls 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 or 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. ==In popular culture==

displays a billiard motif on her missile hatches 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 films Show Boat and 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 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. ==References==