Billiard ball: Difference between revisions

[[File:Billiard ball comparison.jpg|thumb|upright=1.35|{{Cuegloss|Cue ball|Cue balls}}s from (left to right): {{bulleted list

| [[Russian pyramid]] and [[Kaisa (billiards)|kaisa]]—68 mm ({{frac|2|11|16}} in)

| [[Carom billiards|Carom]]—61.5 mm ({{frac|2|7|16}} in)

| International [[pool (cue sports)|pool]]—57.15 mm ({{frac|2|1|4}} in)

| [[Snooker]]—52.5 mm ({{frac|2|1|16}} in)

| [[Blackball (pool)|British-style]] pool—51 mm (2 in)

A '''billiard ball''' is a small, hard [[ball]] used in [[cue sports]], such as [[carom billiards]], [[poolPool (cue sports)|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 [[resilienceResilience (materials science)|resilience]] are important to accuracy.

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;<ref name="Shamos 1999">{{Shamos 1999}}</ref>{{rp|17}} the earliest known written reference to ivory billiard balls is in the 1588 inventory of the [[Duke of Norfolk]].<ref name="Everton 1986">{{cite book |title=The History of Snooker and Billiards |last=Everton |first=Clive |author-link=Clive Everton |location=Haywards Heath, England |publisher=[[Transworld (company)|Partridge Press]] |page=8 |date=1986 |isbn=1-85225-013-5 |quote=11 balls of {{sic|hide=y|yvery}} }} This is a revised version of ''The Story of Billiards and Snooker'', 1979.</ref> Dyed and numbered balls appeared around the early 1770s.<ref name="Shamos 1999" />{{rp|17}} By the mid-19th century, elephants were being slaughtered for their ivory at an alarming rate, just to keep up with the demand for high-end billiard balls – no more than eight balls could be made from a single elephant's tusks.{{citation needed|date=February 2010|reason=When sourced, this should probably be added to the article on elephants.}} The billiard industry realized that the supply of elephants (their primary source of ivory) was [[Endangered species|endangered]], as well as dangerous to obtain (the latter an issue of notable public concern at the turn of the 19th century).<ref name="Shamos 1999" />{{rp|17}} Inventors were challenged to come up with an alternative material that could be [[Manufacturing|manufactured]], with a [[United States dollar|US$]]10,000 (worth approximately ${{formatnum:{{Inflation|US|10000|1869|r=1}}}} in {{CURRENTYEAR}}{{Inflation/fn|US}}) prize being offered by a New York supplier.<ref name="Shamos 1999" />{{rp|17}}

Although not the first artificial substance to be used for the balls (e.g. [[Sorel cement]], invented in 1867, was marketed as an artificial ivory), [[John Wesley Hyatt]] inventedpatented aan composition"ivory materialimitation" incomposite 1869made calledof [[nitrocellulose]], for[[camphor]], billiardand ballsground cattle bone in May 4, 1869 (US patent 5035989582, the first AmericanUS billiard ball patent). The material was a success, and was sold as Bonzoline, Crystalate, Ivorylene until the 1960s, and was used by prominent professional players such as [[John Roberts Jr (billiards player)|John Roberts Jr]] (1847–1919), [[Charles Dawson (billiards player)|Charles Dawson]] (1866–1921), and [[Walter Lindrum]] (1898–1960). The ivory substitute was one the most significant early [[reinforced plastics]]; induced the global growth of billiards, pool, and snooker; and helped create a modern idea that the artificial can surpass the natural.<ref name=":0">{{Cite journal |last1=Neves |first1=Artur |last2=Friedel |first2=Robert |last3=Melo |first3=Maria J. |last4=Callapez |first4=Maria Elvira |last5=Vicenzi |first5=Edward P. |last6=Lam |first6=Thomas |date=1 November 2023 |title=Best billiard ball in the 19th century: Composite materials made of celluloid and bone as substitutes for ivory |url=https://doi.org/10.1093/pnasnexus/pgad360 |journal=PNAS Nexus |volume=2 |issue=11 |doi=10.1093/pnasnexus/pgad360 |issn=2752-6542 |pmc=10651075}}</ref><ref>{{Cite web |last=Neves |first=Artur |title=First successful substitutes for ivory billiard balls) were made with celluloid reinforced with ground cattle bone |url=https://phys.org/news/2023-11-successful-substitutes-ivory-billiard-balls.html |access-date=27 November 2023 |website=Phys.org}}</ref> It is unclear if the cash prize was ever awarded<!--to anyone, that is-->, and there is no evidence suggesting he did in fact win it.<ref name="Shamos 1999" />{{rp|17}}<ref name="Plastiquarian">{{cite web |url=http://www.plastiquarian.com/hyatt.htm |title=Hyatt |yeardate=2002 |work=Plastiquarian.com |location=London |publisher=[[Plastics Historical Society]] |access-date=26 February 2008 |url-status=dead |archive-url=https://web.archive.org/web/20071221114457/http://www.plastiquarian.com/hyatt.htm |archive-date=21 December 2007}}</ref> By 1870 it was commercially branded [[Celluloid]], the first industrial plastic. However, the nature of celluloid made it volatile in production, occasionally exploding, which ultimately made this early plastic impractical.<ref name="Shamos 1999" />{{rp|17}} Subsequently, to avoid the problem of celluloid instability, the industry experimented with various other synthetic materials for billiard balls such as [[Bakelite]], [[poly(methyl methacrylate)|acrylic]], and other plastic compounds.

In the realm of [[carom billiards]] games, three balls are used to play most games on pocketless [[billiards table]]s. Carom balls are not numbered, and are 61–61.5&nbsp;mm (approximately {{frac|2|13|32}} in) in diameter, and a weight ranging between {{convert|205|and|220|g}} with a typical weight of {{convert|7.5|oz|g|order=flip|abbr=on}}.<ref name="UMB-II-12-2">{{cite web |url=http https://wwwfiles.umb-carom.org/Public/Rules/Carom_Rules.pdf |title=World Rules of Carom Billiard |at=Chapter II ("Equipment"), Article 12 ("Balls, Chalk"), Section 2 |work=UMB.org |publisher=[[Union Mondiale de Billard]] |location=Sint-Martens-Latem, Belgium |date=1 January 1989 |access-date=5 March 2007 |url-status=usurped |archive-url=https://web.archive.org/web/20070928031638/http://www.umb.org/Rules/Carom_Rules.pdf |archive-date=2827 SeptemberNovember 20072023}} Officially but somewhat poorly translated version, from the French original.</ref> They are typically colored as follows:

* White: {{Cuegloss|cue ball}} for playerthe 1first player

* Yellow: cue ball for playerthe 2second player (historically this was white with a distinguishing spot)

* Red: the {{Cuegloss|object ball}} ([[Four-ball billiards|four-ball]] uses an extra object ball, usually blue).

{{Clearclear|right}}

|align=center|•||bgcolor="white" colspan=3| ||{{Cuegloss|Cue ball|cue ball}}, white or off-white <br /><small>(sometimes with one or more spots)</small>

The balls are numbered and colored as in the table show here. Balls 1 through 7 are the {{Cuegloss|Suit|suit}} of {{Cuegloss|Solids|solids}} and 9 through 15 are the {{Cuegloss|Stripes|stripes}}. The 8 ball is not considered part of either suit. Striped balls were introduced around 1889.<ref name="Shamos 1999" />{{rp|246}}

[[Rotation (pool)|Rotation]] games do not distinguish between solids and stripes, but rather use the numbering on the balls to determine which {{Cuegloss|Object ball|object ball}} must be pocketed. In other games such as [[straight pool]] neither type of marking is of any consequence.

Some balls used in televised pool games are colored differently in order to make them more distinguishable on television monitors. Most commonly, the dark purple used on the 4 and 12 balls is replaced by pink to make it easier to distinguish the 4 from the black 8 ball, and similarly the 7 and 15 balls use a lighter brown color instead of a deep maroon. Other, less common color substitutions are also found, dependent on manufacturer. These sets often have a cue ball with multiple spots on its surface so that {{Cuegloss|Spin|spin}} placed on it is evident to viewers.

Coin-operated pool tables, such as those found at [[bowling alley]]s, [[amusementAmusement arcade|arcades]], or [[barBar (establishment)|bars]]/[[pub]]s, may use a slightly different-sized cue ball, so that the cue ball can be separated from object balls by the table's ball return mechanism and delivered into its own ball return. Such different sized cue balls are considered less than ideal because they change the dynamics of the equipment. Other tables use a system where a magnet pulls a cue ball with a thin layer of metal embedded inside away from the object ball collection chamber and into the cue ball return, allowing the cue ball to more closely match the object balls in size and weight. More recently, optical systems that recognize the cue ball, which is more translucent than the other balls due to its solid white color, and separate it mechanically have been developed.

{{Clearclear|left}}

===Blackball and British-style eight-ball pool===

In [[blackballEight-ball (pool (British variation)|blackballBritish-style eight-ball pool and its blackball variant]], fifteen object balls are used, but fall into two unnumbered {{Cuegloss|Group|groupsgroup}}s, the {{Cuegloss|Redred ball|reds}} (or less commonly {{Cuegloss|Blueblue ball|blues}}) and {{Cuegloss|Yellowyellow ball|yellows}}, with a white cue ball, and black 8 ball.
[[File:British Style Pool Balls.jpg|left|thumb|145px|Setup for blackball]]
Aside from the 8, shots are not {{Cuegloss|Callcall-shot|called}} since there is no reliable way to identify particular balls to be pocketed. Because they are unnumbered, they are wholly unsuited to certain pool games, such as nine-ball, in which ball order is important. They are typically smaller than the American-style balls; the most common object ball diameters are {{cvt|2|in|mm|0}} and {{cvt|2+1/16|in|mm|0}}.<ref>{{cite web |url= https://www.wepf.org/adm_byelaws.php |title=Section 5: Table and Equipment Specification |websitework=WEPF.org |publisher=[[World Eight-ball Pool Federation]] |access-date=18 January 2022}}</ref> 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.<ref name="Shamos 1999" />{{rp|45}} Such sets were sold by the [[Brunswick Corporation|Brunswick–Balke–Collender Co.]] as early as 1908.<ref name="Shamos 1999" />{{rp|24}} Similar to standard pool balls, there are also special sets designed for televised games; these sets have a black-striped 8 ball, and a spotted cue ball.

| [[File:Snooker_ball_red.png|14px]] {{Cuegloss|Redred ball|Red}} || 1 point

| [[File:Snooker_ball_yellow.png|14px]] {{Cuegloss|Yellowyellow ball|Yellow}} || 2 points

| [[File:Snooker_ball_green.png|14px]] {{Cuegloss|Greengreen ball|Green}} || 3 points

| [[File:Snooker_ball_brown.png|14px]] {{Cuegloss|Brownbrown ball|Brown}} || 4 points

| [[File:Snooker_ball_blue.png|14px]] {{Cuegloss|Blueblue ball|Blue}} || 5 points

| [[File:Snooker_ball_pink.png|14px]] {{Cuegloss|Pinkpink ball|Pink}} || 6 points

| [[File:Snooker_ball_black.png|14px]] {{Cuegloss|Blackblack ball|Black}} || 7 points

Ball sets for [[snooker]] consist of twenty-two balls in total, arranged as a rack of 15 unmarked red balls, six {{Cuegloss|Colourcolour ball|colour balls}}s placed at various predetermined spots on the table, and a white cue ball. The colour balls are sometimes numbered with their point values in the style of pool balls for the home market.

Snooker balls are standardized at {{cvt|52.5|mm|in|frac=16|2}} in diameter within a tolerance of plus or minus {{cvt|0.05|mm|in|3}}. No standard weight is defined, but all balls in the set must be the same weight within a tolerance of {{cvt|3|g|oz|2}}.<ref name="WSAequipspec">[{{cite web |url= http://www.worldsnooker.com/equipment.htm "|title=Equipment"] {{webarchive|archive-url= https://web.archive.org/web/20080801105033/http://www.worldsnooker.com/equipment.htm |archive-date=1 August 2008}}, |work=WorldSnooker.com |publisher=[[World SnookerProfessional Association,Billiards publicationand dateSnooker unknown (RetrievedAssociation]] |access-date=28 January 2007), |location=London, UK.}}</ref> 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 {{cvt|2+1/8|in|mm|1}}, 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.<ref>{{cite web |title=An Introduction to Croquet: A Brief History |url= https://www.croquet.org.uk/?p=games/CroquetIntro#history |publisher=The [[Croquet Association]] (of England and Wales)|work=Croquet.org.uk |access-date=13 May 2017}}</ref>

{{Clear|both}}

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 {{convert|68|mm|in|frac=16}}. [[Kaisa (cue sport)|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.<ref name="BVRP">{{cite web |url= https://cuesup.com/russian-pyramid-pool-a-game-bearing-more-games/ |title=Russian Billiards |work=CuesUp.com |author=<!--Staff writer; no byline.--> |yeardate=2016 |access-date=2016-12-28 December 2016}}</ref>

The term "8-ball" is also [[slang]] both for {{convert|1/8|oz|g}} of [[cocaine]] or [[crystalCrystal methamphetamine|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]].<ref name="IEOB">{{cite book |last=Shamos |first=Michael Ian |yearauthor-link=Michael Ian Shamos |date=1993 |title=The Illustrated Encyclopedia of Billiards |publisher=Lyons & Burford |location=New York City |pages=[https://archive.org/details/illustratedencyc0000sham/page/85 85, 128, and 168] |isbn=1-55821-219-1 |url= https://archive.org/details/illustratedencyc0000sham/page/85 |via=Internet Archive}}</ref><ref>{{cite journal |last=Jewett |first=Bob |date=February 2002 |title=8-Ball Rules: The many different versions of one of today's most common games |journal=Billiards Digest Magazine |pages=22–23}}</ref><ref>{{cite web |first=Ralph |last=Hickok (|date=2001). [|url= http://www.hickoksports.com/history/billiard.shtml |title=Sports History: Pocket Billiards] {{webarchive|work=HickokSports.com |archive-url= http://webarchive.loc.gov/all/20020223060649/http://www.hickoksports.com/history/billiard.shtml |archive-date=23 February 2002}}. Retrieved |access-date=22 February 2007.}}</ref><ref>{{cite web |publisher=Billiard Congress America (1995–2005)|date=2019 [http|orig-date=2001 |url= https://www.bca-pool.com/aboutuspage/history/start.shtml39 |title=About the Industry: A Brief History of the Noble Game of Billiards] {{webarchive|urlfirst=https://web.archive.org/web/20070127151057/http://www.bcaMike |last=Shamos |author-pool.com/aboutus/history/start.shtmllink=Michael Ian Shamos |access-date=27 JanuaryNovember 2007}} by Mike Shamos. Retrieved 22 February 2007.</ref><ref name="Mizerak">{{cite book |authorfirst1=Steve |last1=Mizerak and|author1-link=Steve Mizerak |first2=Michael E. |last2=Panozzo |title=Steve Mizerak's Complete Book of Pool |publisher=Contemporary Books |location=[[Chicago|Chicago, Ill]] |pages=[https://archive.org/details/stevemizerakscom00mize/page/127127–128 127–8]|via=Internet Archive |yeardate=1990 |isbn=0-8092-4255-9 |url= https://archive.org/details/stevemizerakscom00mize/page/127}}</ref>

Because the [[collisionCollision#Billiards|collisions between billiard balls]] are nearly [[elasticElastic collision|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 [[mathematicsMathematics|mathematical]] theorems and [[physics]] models, and figure in [[dynamical billiards]], [[scattering theory]], [[Lissajous knots]], [[billiard ball computing]], and [[reversibleReversible cellular automaton|reversible cellular automata]], [[Polchinski's paradox]], [[contact dynamics]], [[collision detection]], the [[illumination problem]], [[ultracoldUltracold atom|atomic ultracooling]], [[quantum mirage]]s, and elsewhere in these fields.

The phrase "as smooth as a billiard ball" is sometimes applied to describe a [[baldnessBaldness|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 inby 2008's'[[Discover (magazine)|Discover]]'' Magazinemagazine in 2008,<ref>{{cite web |last=Plait |first=Phil |url= https://www.discovermagazine.com/the-sciences/ten-things-you-dont-know-about-the-earth |title=Ten things you don't know about the Earth |work=[[Discover (magazine)|Discover]] |publisher=Bad[[Kalmbach AstronomyPublishing]] |date=8 September 2008 |access-date=8 September 2008}}</ref> stating no diameter variations measuring +/- {{convert|0.005"|in|mm}} should be madedetectable, 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 {{convert|0.0049"|in|mm}}, which is near the maximum diameter tolerance.<ref>{{cite web |first=M. Özgür |last=Nevres |url= https://ourplnt.com/earth-smooth-billiard-ball/ |title=Is Earth as smooth as a billiard ball? No, here's why |publisherwork=Our Planet |date=17 August 2017 |access-date=17 August 2017}}</ref> {{crossref|(seeSee also: [[{{section link|Earth#Size and shape|Earth's shape]]}}.)}}