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FOUR IS THE MOST EPIC NUMBER THERE IS! GO FOR TEH EPIX! THE BEST NUMBER IS FOUR! DON'T FORGET IT!
{| class="infobox" style="width: 20em;"
|-
| colspan="2" align="center" | <div style="align:center;font-size:1000%;font-family:times;padding: 0.5em 0">4</div>
|-
| colspan="2" | {{numbers (digits)}}
|-
| [[Cardinal number|Cardinal]]
| 4 <br> four
|-
| [[Ordinal numbers (linguistics)|Ordinal]]
| 4th <br> fourth
|-
| [[Numeral system]]
| [[Quaternary numeral system|quaternary]]
|-
| [[Factorization]]
| <math> 2^2 </math>
|-
| [[Divisor]]s
| 1, 2, 4
|-
| [[Roman numeral]]
| IV ''or'' IIII
|-
| Roman numeral (Unicode)
| Ⅳ, ⅳ
|-
| [[Arabic language|Arabic]] || <font style="font-size:150%;">٤</font>
|-
| Arabic ([[Urdu]]) || <font style="font-size:150%;">۴</font>
|-
| [[Ge'ez alphabet|Ge'ez]] || <font style="font-size:100%;">፬</font>
|-
| [[Bengali language|Bengali]] || <font style="font-size:150%;">৪</font>
|-
| [[Chinese numeral]] || 四
|-
| [[Devanāgarī|Devanagari]] || <font style="font-size:150%;">४</font>
|-
| [[Hebrew (language)|Hebrew]] || ארבע (Arba, pronounced are-buh) or <font style="font-size:150%;">ד</font> ([[Dalet]], 4th letter of the Hebrew alphabet)
|-
| [[Khmer numerals|Khmer]] || ៤
|-
| [[Thai numerals|Thai ]] || ๔
|-
| [[numerical prefix|prefix]]es
| [[Wiktionary:tetra-|tetra-]] (from [[Greek language|Greek]])
[[Wiktionary:quadri-|quadri-]]/[[Wiktionary:quadr-|quadr-]] (from [[Latin]])
|-
| [[Binary numeral system|Binary]]
| 100
|-
| [[Octal]]
| 4
|-
| [[Duodecimal]]
| 4
|-
| [[Hexadecimal]]
| 4
|-
| [[Vigesimal]]
| 4
|}
{{wiktionary|four}}
<center>''This article discusses the number '''Four'''. For the year 4 AD, see [[4]]. For other uses of 4, see [[4 (disambiguation)]]''</center>


<math>4+4*44=444</math>
'''4''' ('''four''') is a [[number]], [[numeral]], and [[glyph]]. It is the [[natural number]] following [[3 (number)|3]] and preceding [[5 (number)|5]]. Four is the only number in the [[English language]] for which the number of [[letter]]s in its name is [[Equality (mathematics)|equal]] to the number itself. This is also true in several other languages, such as German, Afrikaans, Dutch, and Flemish, as "vier".{{Fact|date=March 2008}}

==In mathematics==
Four is the smallest [[composite number]], its proper [[divisor]]s being {{num|1}} and {{num|2}}.
Four is also a [[highly composite number]]. The next highly composite number is {{num|6}}.

Four is the second [[square number]], the second [[centered triangular number]].

4 is the smallest squared prime (<math> p^2 </math>). It has an [[aliquot sum]] of [[3]] which is itself prime. The [[aliquot sequence]] of 4 has 4 members (4,[[3 (number)|3]],1,0).

The prime factorization of four is two times two.

Four is the smallest composite number that is equal to the sum of its prime factors. (As a consequence of this, it is the smallest [[Smith number]]). However, it is the largest (and only) composite number <math>n</math> for which <math>(n - 1)!\ \equiv\ 0 \ ({\rm mod}\ n)</math> is false.

It is also a [[Motzkin number]].

In addition, <math> 2 + 2 = 2 \times 2 = 2^2 = 4 </math>. Continuing the pattern in [[Knuth's up-arrow notation]], <math> 2 \uparrow\uparrow 2 = 2 \uparrow\uparrow\uparrow 2 = 4</math>, and so on, for any number of up arrows.

A four-sided plane figure is a [[quadrilateral]] (quadrangle) or [[square (geometry)|square]], sometimes also called a ''tetragon''. A [[circle]] divided by 4 makes [[right angle]]s. Because of it, four (4) is the base number of [[plane (mathematics)]]. Four [[cardinal directions]], [[four seasons]], [[duodecimal]] system, and [[vigesimal]] system are based on four.

A solid figure with four faces is a [[tetrahedron]]. The regular tetrahedron is the simplest [[Platonic solid]]. A [[tetrahedron]], which can also be called a 3-[[simplex]], has four triangular faces and four vertices. It is the only self-dual [[regular polyhedron]].

[[Fourth dimension|Four-dimensional]] space has the largest number of dimensions used by more than three convex regular figures. There are infinitely many convex [[regular polygon]]s (two-dimensional); five convex [[Regular polyhedron|regular polyhedra]] (three-dimensional, the five [[Platonic Solid]]s); six [[Convex regular 4-polytope|convex regular polychora]] (four-dimensional); and three regular convex [[polytope]]s occupying each higher-dimensional space.

The smallest non-[[cyclic group|cyclic]] [[group (mathematics)|group]] has four elements; it is the [[Klein four-group]]. Four is also the order of the smallest non-trivial groups that are not [[simple group|simple]].

Four is the maximum number of dimensions of a real [[division algebra]] (the [[quaternions]]), by a theorem of [[Ferdinand Georg Frobenius]].

The [[four-color theorem]] states that a [[planar graph]] (or, equivalently, a flat [[map]] of two-dimensional regions such as countries) can be colored using four colors, so that adjacent vertices (or regions) are always different colors. Three colors are not, in general, sufficient to guarantee this. The largest planar [[complete graph]] has four vertices.

[[Lagrange's four-square theorem]] states that every positive integer can be written as the sum of at most four [[square number]]s. Three are not always sufficient; [[seven|7]] for instance cannot be written as the sum of three squares.

Four is the first positive non-[[Fibonacci number]].

Each natural number divisible by 4 is a difference of squares of two natural numbers, i.e. <math> 4x = y^2 - z^2. </math>

Four is an [[Harshad number|all-Harshad number]] and a [[semi-meandric number]].

===List of basic calculations===

{|class="wikitable" style="text-align: center; background: white"
|-
!width="105px"|[[Multiplication]]
!1
!2
!3
!4
!5
!6
!7
!8
!9
!10
!width="5px"|
!11
!12
!13
!14
!15
!16
!17
!18
!19
!20
!width="5px"|
!21
!22
!23
!24
!25
!width="5px"|
!50
!100
!1000
|-
|<math>4 \times x</math>
|'''4'''
|[[8 (number)|8]]
|[[12 (number)|12]]
|[[16 (number)|16]]
|[[20 (number)|20]]
|[[24 (number)|24]]
|[[28 (number)|28]]
|[[32 (number)|32]]
|[[36 (number)|36]]
|[[40 (number)|40]]
!
|[[44 (number)|44]]
|[[48 (number)|48]]
|[[52 (number)|52]]
|[[56 (number)|56]]
|[[60 (number)|60]]
|[[64 (number)|64]]
|[[68 (number)|68]]
|[[72 (number)|72]]
|[[76 (number)|76]]
|[[80 (number)|80]]
!
|[[84 (number)|84]]
|[[88 (number)|88]]
|[[92 (number)|92]]
|[[96 (number)|96]]
|[[100 (number)|100]]
!
|[[200 (number)|200]]
|[[400 (number)|400]]
|[[4000 (number)|4000]]
|}

{|class="wikitable" style="text-align: center; background: white"
|-
!width="105px"|[[Division (mathematics)|Division]]
!1
!2
!3
!4
!5
!6
!7
!8
!9
!10
!width="5px"|
!11
!12
!13
!14
!15
|-
|<math>4 \div x</math>
|'''4'''
|2
|<math>1.\overline{3}</math>
|1
|[[0 (number)|0]].8
|<math>0.\overline{6}</math>
|<math>0.\overline{5}7142\overline{8}</math>
|0.5
|<math>0.\overline{4}</math>
|0.4
!
|<math>0.\overline{3}\overline{6}</math>
|<math>0.\overline{3}</math>
|<math>0.\overline{3}0769\overline{2}</math>
|<math>0.\overline{2}8571\overline{4}</math>
|<math>0.2\overline{6}</math>
|-
|<math>x \div 4</math>
|0.[[25 (number)|25]]
|0.5
|0.[[75 (number)|75]]
|1
|1.25
|1.5
|1.75
|2
|2.25
|2.5
!
|2.75
|3
|3.25
|3.5
|3.75
|}

{|class="wikitable" style="text-align: center; background: white"
|-
!width="105px"|[[Exponentiation]]
!1
!2
!3
!4
!5
!6
!7
!8
!9
!10
!width="5px"|
!11
!12
!13
|-
|<math>4 ^ x\,</math>
|4
|16
|64
|[[256 (number)|256]]
|1024
|4096
|16384
|65536
|262144
|1048576
!
|4194304
|16777216
|67108864
|-
|<math>x ^ 4\,</math>
|1
|16
|[[81 (number)|81]]
|256
|625
|1296
|2401
|4096
|6561
|[[10000 (number)|10000]]
!
|14641
|20736
|28561
|}

== Evolution of the glyph ==
[[Image:Evolution4glyph.png]]

Representing 1, 2 and 3 in as many lines as the number represents worked well enough, but writing four lines proved tiresome. The [[Brahmin]] Indians simplified 4 by joining its four lines into a cross that looks like our modern plus sign. The [[Sunga empire|Sunga]] and other Indians would add a horizontal line on top of the numeral, and the Kshatrapa and Pallava evolved the numeral to a point where speed of writing was at best a secondary concern. The [[Arab]]s didn't have time for cursive fancy: their 4 still had the early concept of the cross, but for the sake of efficiency, was made in one stroke by connecting the "western" end to the "northern" end; the "eastern" end was finished off with a curve. The Europeans dropped off the finishing curve and gradually made the numeral less cursive, ending up with a glyph very close to the original Brahmin cross.<ref>Georges Ifrah, ''The Universal History of Numbers: From Prehistory to the Invention of the Computer'' transl. David Bellos et al. London: The Harvill Press (1998): 394, Fig. 24.64</ref>

While the shape of the 4 character has an [[ascender]] in most modern [[typeface]]s, in typefaces with [[text figures]] the character usually has a [[descender]], as, for example, in [[Image:TextFigs148.png]].

[[Image:Seven-segment 4.svg|25px|left]]On the [[seven-segment display]]s of pocket calculators and digital watches, 4 is seen with an open top.
&nbsp;

==In religion==
*The [[Tetragrammaton]] is the four-letter name of [[God]].
*The four Matriarchs (foremothers) of [[Judaism]] are [[Sarah]], [[Rebeccah]], [[Leah]], and [[Rachel]].
*The Four Arch Angels in Islam are: Jibraeel (Gabriel), Mikaeel (Michael), Izraeel (Azrael), and Israfil (Raphael)
*The [[Four Species]] ([[lulav]], [[hadass]], [[Aravah (Sukkot)|aravah]] and [[etrog]]) are taken as one of the [[mitzvah|mitzvot]] on the [[Jewish]] holiday of [[Sukkot]]. ([[Judaism]])
*The Four Cups of Wine to drink on the [[Jewish]] holiday of [[Passover]]. ([[Judaism]])
*The Four Questions to be asked on the [[Jewish]] holiday of [[Passover]]. ([[Judaism]])
*The Four Sons to be dealt with on the [[Jewish]] holiday of [[Passover]]. ([[Judaism]])
*The Four Expressions of Redemption to be said on the [[Jewish]] holiday of [[Passover]]. ([[Judaism]])
*The [[Four Horsemen of the Apocalypse]] ride in the [[Book of Revelation]].
*Four is the sacred number of the [[Zia]], an indigenous tribe located in the [[United States]] State of [[New Mexico]].
*The Chinese and the Japanese are superstitious about the number four because it is a homonym for "Death" in their languages
*The [[Four Noble Truths]] of [[Buddhism]].
*The four [[Gospel]]s: [[Gospel of Matthew|Matthew]], [[Gospel of Mark|Mark]], [[Gospel of Luke|Luke]], and [[Gospel of John|John]].

==In science==
===In astronomy===
* The orbits of four planets in the [[solar system]] lie within that of the [[asteroid belt]].
* Four terrestrial (or rocky) planets in the [[Solar system]]: [[Mercury (planet)|Mercury]], [[Venus (planet)|Venus]], [[Earth]], [[Mars (planet)|Mars]].
* Four giant gas planets in the [[Solar system]]: [[Jupiter (planet)|Jupiter]], [[Saturn (planet)|Saturn]], [[Uranus (planet)|Uranus]], [[Neptune (planet)|Neptune]].
* Four of Jupiter's moons (the [[Galilean moons]]) are readily visible from Earth.
* [[Messier object]] [[Messier 4|M4]], a magnitude 7.5 [[globular cluster]] in the constellation [[Scorpius]].
* The [[New General Catalogue]] [http://www.ngcic.org/ object] [[NGC 4]], a faint [[galaxy]] in the [[constellation]] [[Pisces (constellation)|Pisces]]
* The [[Saros]] [http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1-175.html number] of the [[solar eclipse]] series which began on [[-2731]] [[May 6]] and ended on [[-1451]] [[June 13]]. The duration of Saros series 4 was 1280.1 years, and it contained 72 solar eclipses.
* The Saros [http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html number] of the [[lunar eclipse]] series which began on [[-2700]] [[September 3]] and ended on [[-1131]] [[April 2]]. The duration of Saros series 4 was 1568.6 years, and it contained 88 lunar eclipses.
* The Roman numeral IV stands for [[subgiant]] in the [[stellar classification|Yerkes spectral classification scheme]].
* The Roman numeral IV (usually) stands for the fourth-discovered satellite of a planet or minor planet (e.g. [[Jupiter IV]])

===In biology===
* Four is the number of [[nucleobase]] types in [[DNA]] and [[RNA]] - [[adenine]], [[guanine]], [[cytosine]], [[thymine]] ([[uracil]] in [[RNA]]).
* Many [[chordate]]s have four feet, legs or leglike appendages ([[Tetrapods]]).
* The [[mammal]]ian [[heart]] consists of four chambers.
* Many [[mammal]]s ([[Carnivora]], [[Ungulata]]) use four fingers for movement.
* The fourth finger of a human hand (on the left hand - ring-finger) is moved when the little finger moves.
* [[butterfly|Butterflies]] and [[dragonfly|dragonflies]] have four [[wing]]s.
* There are four human [[blood]] groups (A, B, O, AB).
* People have four [[Canine tooth|canines]], four [[incisor]] and four [[Wisdom teeth|wisdom]] [[Tooth|teeth]].

===In chemistry===
*Valency of [[carbon]] (that is basis of life on the Earth) is four. Thanks to its tetrahedral crystal bond structure [[diamond]] (one of the natural allotropes of carbon) is the hardest known naturally occurring material. It is also the valence of [[silicon]], whose compounds form the majority of the mass of the Earth's crust.
*The [[atomic number]] of [[beryllium]]
* There are four basic states of [[matter]]: [[solid]], [[liquid]], [[gas]], and [[plasma (physics)|plasma]].

===In physics===
* [[Special relativity]] and [[general relativity]] treats nature as four-[[dimension]]al &mdash; [[time]] and three-dimensional [[space]] are treated together and called [[spacetime]].
* An [[alpha particle]] (helium nucleus, also called a helion) consists of four [[hadron]]s.
* There are four [[fundamental forces]] ([[electromagnetism]], [[gravity]], the [[weak nuclear force]], and the [[strong nuclear force]]).

==In logic and philosophy==
*The symbolic meanings of the number four are linked to those of the cross and the square. 'almost from prehistoric times, the number four was employed to signify what was solid, what could be touched and felt. its relationship to the cross (four points) made it an outstanding symbol of wholeness and universality, a symbol which drew all to itself'. where lines of latitude and longitude intersect, they divide the earth into four proportions. throughout the world kings and chieftains have been called 'lord of the four suns'...'lord of the four quarters of the earth'... by which is understood to the extent of their powers both territorially and in terms of total control of their subjects' doings.
*The [[Square of Opposition]], in both its [[Square of Opposition|Aristotelian version]] and its [[Square of Opposition#The modern square of opposition|Boolean version]], consists of four forms: A ("All ''S'' is ''R''"), I ("Some ''S'' is ''R''"), E ("No ''S'' is ''R''"), and O ("Some ''S'' is not ''R''").
*[[Aristotle]] held that there are basically [[Aristotle#Causality|four causes]] in nature: the [[efficient cause]], the [[Material cause|matter]], the [[Final cause|end]], and the [[Formal cause|form]].
*[[Immanuel Kant]] expounded a [[Category (Kant)#The table of judgments|table of judgments]] involving four three-way alternatives, in regard to 1. Quantity, 2. Quality, 3. Relation, 4. Modality, and, based thereupon, a [[Category (Kant)#The table of categories|table of four categories]], named by the terms just listed, and each with three subcategories.
*[[Arthur Schopenhauer]]'s doctoral thesis was ''[[On the Fourfold Root of the Principle of Sufficient Reason]]''.
*[[Charles Sanders Peirce|C.S. Peirce]], usually a trichotomist, discussed four basic methods of seeking to settle questions and arrive at firm beliefs: the method of tenacity (sticking to that which one is inclined to think), the method of authority, the ''a priori'' method, and the method of science. (See "The Fixation of Belief," 1877, [http://www.peirce.org/writings/p107.html Eprint].)
*[[Jonathan Lowe]] (E.J. Lowe) argues in ''The Four-Category Ontology,'' 2006, for four categories: objects, attributes, kinds, and modes (by "modes" he means property-particulars, also known as "[[Trope (philosophy)|tropes]]"). (See Lowe's "Recent Advances in Metaphysics," 2001, [http://www.cs.vassar.edu/~weltyc/fois/fois-2001/keynote/ Eprint])

==In technology==
[[Image:U+2676 DejaVu Sans.svg|50px|right|4 as a resin identification code, used in recycling.]]
* The [[resin identification code]] used in recycling to identify [[low-density polyethylene]].
*Most [[vehicle]]s have four [[wheel]]s.

*Most [[furniture]] has four legs - tables, chairs, etc.

*Four [[horse]]s (quadriga) is the maximal number of horses in one row for carriage.

*The [[four color process]] ([[CMYK]]) is used for [[printing]].

*Wide use of [[rectangle]]s (with four angles and four sides) because they have effective form and capability for close adjacency to each other (houses, rooms, tables, bricks, sheets of paper, screens, film frames).

*In the [[Rich Text Format]] specification, language code 4 is for the [[Chinese language]]. Codes for regional variants of Chinese are congruent to 4 mod 256.

*[[Credit card]] machines have four-twelve function keys.

*On most phones, the 4 key is associated with the letters [[G]], [[H]], and [[I]], but on the [[BlackBerry]] it is the key for [[D]] and [[F]].

*On many [[computer keyboard]]s, the "4" key may also be used to type the [[dollar sign]] ($) if the [[shift key]] is held down.

*It is the number of [[bit]]s in a [[nibble]], equivalent to half a [[byte]]

*In [[internet slang]], "4" can replace the word "for" (as "four" and "for" are pronounced similarly). For example, typing "4u" instead of "for you".

*In [[Leet]]speak, "4" may be used to replace the letter "A".

*In Expressing love, "4" may be used to replace the word "Love" (143).

==In sports==
In the [[sport]] of [[cricket]], a [[boundary (cricket)|four]] is a specific type of scoring event, scoring four runs.

In [[rugby union]], the number of the [[Rugby union positions#4. & 5. Lock|lock forward]], who usually jumps at number 2 in the [[line-out]].

In [[rugby league]], the number of one of the two [[Rugby league positions#Centre|centres]]. It is also the number of points awarded for a [[try]].

In [[baseball]], 4 represents the [[second baseman]]'s position. It was also the jersey number of [[Lou Gehrig]], [[Mel Ott]], [[Joe Cronin]], and [[Paul Molitor]]. It was the jersey number of [[Earl Weaver]], long-time manager of the Baltimore Orioles.

In [[basketball]], 4 represents the [[power forward (basketball)|power forward]] position. Also, The term [[Final Four]] refers to the last four teams remaining in the NCAA playoff tournament. If a player completes a [[three-point field goal|three-pointer]] while being fouled, the player is awarded one free-throw for a possible 4-point-play. The number for the Toronto Raptors forward [[Chris Bosh]].

In [[ice hockey]], 4 was the jersey number worn by Hall of Famers [[Jean Beliveau]], [[Bobby Orr]], [[Scott Stevens]] and [[Rob Blake]].

In [[American football]], 4 is today most commonly identified with the jersey number of former [[Green Bay Packers]] quarterback [[Brett Favre]].

In [[Rowing (sport)|rowing]], a four refers to a [[boat]] for four rowers, with or without [[coxswain]]. In rowing nomenclature 4- reprsents a coxless four and 4+ represents a coxed four.

In [[football (soccer)|soccer football]], number 4 is often assigned to a [[centre back]].and a number of luck.

==In other fields==
[[Image:ICS Four.svg|right|thumb|100px|[[International maritime signal flag]] for 4]]
''See also '''[[4 (disambiguation)]]'''.
*Four is the universal number for women, as symbolically suggested in literature throughout history{{Fact|date=April 2008}}
*Four can be used as an [[obscenity]] in some technologically adept circles, replacing the common word for fornication. This usage derives from the fact that when counting in binary on ones fingers, 4, whose binary representation is 00100<sub>2</sub> is represented by raising the [[middle finger]] of one hand, yielding a vulgar gesture. A stronger variation uses the number [[132 (number)|132]], whose binary representation 0010000100 replicates this gesture on both hands.
*A [[four-letter word]] is used to describe most [[swear]] words in the [[English language]], as most such terms do indeed possess four letters.
*Four (四, formal writing: 肆, [[pinyin]] sì) is considered an [[unlucky number]] in [[Chinese culture|Chinese]], [[Korean culture|Korean]], and [[Culture of Japan|Japanese]] cultures because it sounds like the word "death" (死, [[pinyin]] sǐ). Due to that, many numbered product lines skip the "four": e.g. [[Nokia]] [[cell phones]] (there is no series beginning with a 4), [[PalmOne, Inc.|Palm]] [[Personal digital assistant|PDAs]], the [[Leisure Suit Larry]] games, etc. Some buildings skip floor 4 or replace the number with the letter "F", particularly in heavily Asian areas. ''See [[tetraphobia]]'' and ''[[Numbers in Chinese culture]]''.
*In the [[NATO phonetic alphabet]], the digit 4 is called "fower".
*The number of characters in a canonical [[four-character idiom]].
*The number of strings on a [[violin]], a [[viola]], a [[cello]], [[double bass]], a [[cuatro (instrument)|cuatro]] and a [[ukulele]], and the number of string pairs on a [[mandolin]].
*The designation of [[Interstate 4]], a freeway in [[Florida]].
*The number of arms possessed by video game villain [[Goro (Mortal Kombat)|Goro]].
*The number of fingers that people have in many [[animated cartoon]]s.
*'''''[[Four (album)|Four]]''''', an album by [[Blues Traveler]]
*'''''[[4 (Foreigner album)|4]]''''', an album by [[Foreigner (band)|Foreigner]]
*The number of completed, numbered symphonies by [[Johannes Brahms]]
*In [[Astrology]], [[Cancer (constellation)|Cancer]] is the 4th [[astrological sign]] of the [[Zodiac]].
*4 is one of the "[[Mythology of Lost#The_Numbers|Lost Numbers]]" on the television show, ''[[Lost (TV series)|Lost]]'', along with [[8 (number)|8]], [[15 (number)|15]], [[16 (number)|16]], [[23 (number)|23]], and [[42 (number)|42]].
*[[Arthur Conan Doyle]] wrote a book titled "[[The Sign of Four]]"
*In Tetris, every shape in the game is formed of 4 blocks each. Also the game was named after "tetra" the Greek word for 4.

==In Music==
In [[Western Music]], [[common time]] is constructed of four beats.

== Groups of four ==
* Four rules : [[addition]], [[subtraction]], [[multiplication]], [[division (mathematics)|division]].
* [[Classical element#Classical Elements in Greece|Greek classical elements]] ([[fire]], [[air]], [[water]], [[earth]]).
* [[Season|Four seasons]] : [[Spring (season)|spring]], [[summer]], [[autumn]], [[winter]].
* Four parts of a [[day]] : [[night]], [[morning]], [[afternoon]], [[evening]].
* Four [[cardinal directions]] : [[north]], [[south]], [[east]], [[west]].
* [[Four Temperaments]] : [[sanguine]], [[choleric]], [[melancholic]], [[phlegmatic]].
* [[Humorism| Four Humors]] : [[blood]], [[yellow bile]], [[black bile]], [[phlegm]].
* [[Four Great Ancient Capitals of China]]
* [[Four corner method]]
* [[Four cardinal principles|cardinal principles]]
* Four canonical [[Christianity|Christian]] [[Gospels]], attributed to the [[Four Evangelists]] ([[Matthew the Evangelist|Matthew]], [[Mark the Evangelist|Mark]], [[Luke the Evangelist|Luke]], and [[John the Evangelist|John]])
* [[Four horsemen of the Apocalypse]] : [[war]], [[famine]], [[pestilence]], [[death]].
* Four [[suit (cards)|suits]] of [[playing card]]s : hearts, diamonds, clubs, spades.
* Four US time zones: Pacific, Mountain, Central, and Eastern.
* The number of tines of most [[fork]]s.
* Four [[nation]]s of the [[United Kingdom]]: [[England]], [[Wales]], [[Scotland]], [[Northern Ireland]].
* [[Four Noble Truths]] in the [[Buddhist]] religion.
* Four estates : [[politics]], [[Public administration|administration]], [[judiciary]], [[journalism]]. Especially in the expression "[[Fourth Estate]]", which means journalism.
* [[Four Corners Monument|Four Corners]] is the only location in the [[United States]] where four [[U.S. state|states]] come together at a single point: [[Colorado]], [[Utah]], [[New Mexico]], and [[Arizona]].
* The [[Fantastic Four]]: Mr. Fantastic, The Invisible Woman, The Human Torch, and The Thing.
* The [[Teenage Mutant Ninja Turtles]]: Leonardo, Donatello, Rafael, and Michelangelo.
* Typically there are four movements in a classical [[symphony]] or [[string quartet]].
* [[The Beatles]] were also known as the 'Fab Four': John Lennon, Ringo Starr, George Harrison, and Paul McCartney.
* The [[Gang of Four]] was a group of [[Communist Party]] leaders in the [[People's Republic of China]] who were blamed for the [[Cultural Revolution]].
* [[Gang of Four (band)|Gang of Four]] is a British [[post-punk]] [[rock and roll|rock]] band formed in the late 1970s.
* There are also four members in a [[quartet]]. See also [[List of musical quartets]].
* The arcade game [[Pac-Man]], the main character is constantly on the run from four ghosts named Inky, Blinky, Pinky and Clyde.
* Similarly, in the sequel to [[Pac-Man]], [[Ms. Pac-Man]], there are four ghosts named Inky, Blinky, Pinky and Sue.
* Four food groups (Meat products, dairy products, grain products, and fruits/vegetables). Note that this traditional model is falling out of favour, as fruits and vegetables became separate groups in the 1992 USDA [[food guide pyramid]]. Also, refined fats and sugars constitute another group (traditionally considered non-essential).
* Four rivers in the [[Garden of Eden]] ([[Book of Genesis|Genesis]] 2:10&ndash;14): [[Pishon]] (perhaps the Jaxartes or [[Syr Darya]]), [[Gihon]] (perhaps the Oxus or [[Amu Darya]]), Hiddekel ([[Tigris]]), and P'rat ([[Euphrates]])
* Number of protruding limbs on the Human Body
*[[Teletubbies]]

==References==

{{reflist}}

* Wells, D. ''The Penguin Dictionary of Curious and Interesting Numbers'' London: Penguin Group. (1987): 55 - 58

==External links==
* [http://www.marijn.org/everything-is-4 Marijn.Org on Why is everything four?]
* [http://www.samuel-beckett.net/Penelope/four_symbolism.html A few thoughts on the number four], by Penelope Merritt at samuel-beckett.net

[[Category:Integers|04]]
[[Category:Superstitions]]

[[ar:4 (عدد)]]
[[arc:4 (ܡܢܝܢܐ)]]
[[gn:Irundy]]
[[ay:Pusi]]
[[ca:Quatre]]
[[cv:4 (хисеп)]]
[[ceb:4 (numero)]]
[[cs:4 (číslo)]]
[[co:4 (numeru)]]
[[cy:Pedwar]]
[[da:4 (tal)]]
[[pdc:Vier]]
[[de:Vier]]
[[myv:4 (ниле)]]
[[es:Cuatro]]
[[eo:Kvar]]
[[eu:Lau]]
[[fa:۴ (عدد)]]
[[fr:4 (nombre)]]
[[gan:4]]
[[ko:4]]
[[ig:Anọ]]
[[id:4 (angka)]]
[[ia:4 (numero)]]
[[xh:Zine]]
[[it:4 (numero)]]
[[he:4 (מספר)]]
[[rw:Kane]]
[[kg:4 (ntalu)]]
[[ht:4 (nonm)]]
[[ku:Çar (hejmar)]]
[[la:Quattuor]]
[[lb:Véier]]
[[lt:4 (skaičius)]]
[[lmo:Nümar 4]]
[[hu:4 (szám)]]
[[nah:Nāhui]]
[[nl:4 (getal)]]
[[ja:4]]
[[no:4 (tall)]]
[[nn:Talet 4]]
[[pl:4 (liczba)]]
[[pt:Quatro]]
[[qu:Tawa]]
[[ru:4 (число)]]
[[scn:Quattru]]
[[simple:Four]]
[[sl:4 (število)]]
[[sr:4 (број)]]
[[fi:4 (luku)]]
[[sv:4 (tal)]]
[[tl:4 (bilang)]]
[[th:4]]
[[vi:4 (số)]]
[[tr:4 (sayı)]]
[[uk:4 (число)]]
[[vls:4 (getal)]]
[[yi:4 (נומער)]]
[[zh-yue:4]]
[[zh:4]]

Revision as of 08:03, 10 June 2008

FOUR IS THE MOST EPIC NUMBER THERE IS! GO FOR TEH EPIX! THE BEST NUMBER IS FOUR! DON'T FORGET IT!

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