8 (eight) is the

natural number In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country"). Numbers used for counting are called ''cardinal ...

following 7 and preceding 9.

In mathematics

8 is: * a

composite number A composite number is a positive integer that can be formed by multiplying two smaller positive integers. Equivalently, it is a positive integer that has at least one divisor other than 1 and itself. Every positive integer is composite, prime, ...

, its

proper divisor In mathematics, a divisor of an integer n, also called a factor of n, is an integer m that may be multiplied by some integer to produce n. In this case, one also says that n is a multiple of m. An integer n is divisible or evenly divisible by ...

s being , , and . It is twice 4 or four times 2. * a

power of two A power of two is a number of the form where is an integer, that is, the result of exponentiation with number two as the base and integer as the exponent. In a context where only integers are considered, is restricted to non-negativ ...

, being 2 (two cubed), and is the first number of the form , being an integer greater than 1. * the first number which is neither

prime A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways ...

nor

semiprime In mathematics, a semiprime is a natural number that is the product of exactly two prime numbers. The two primes in the product may equal each other, so the semiprimes include the squares of prime numbers. Because there are infinitely many prime ...

. * the base of the

octal The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. This is to say that 10octal represents eight and 100octal represents sixty-four. However, English, like most languages, uses a base-10 number ...

number system, which is mostly used with computers. In octal, one digit represents three

bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...

s. In modern computers, a

byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...

is a grouping of eight bits, also called an

octet Octet may refer to: Music * Octet (music), ensemble consisting of eight instruments or voices, or composition written for such an ensemble ** String octet, a piece of music written for eight string instruments *** Octet (Mendelssohn), 1825 compos ...

. * a

Fibonacci number In mathematics, the Fibonacci numbers, commonly denoted , form a sequence, the Fibonacci sequence, in which each number is the sum of the two preceding ones. The sequence commonly starts from 0 and 1, although some authors start the sequence from ...

, being plus . The next Fibonacci number is . 8 is the only positive Fibonacci number, aside from 1, that is a perfect cube. * the only nonzero

perfect power In mathematics, a perfect power is a natural number that is a product of equal natural factors, or, in other words, an integer that can be expressed as a square or a higher integer power of another integer greater than one. More formally, ''n'' ...

that is one less than another perfect power, by

Mihăilescu's Theorem Catalan's conjecture (or Mihăilescu's theorem) is a theorem in number theory that was conjectured by the mathematician Eugène Charles Catalan in 1844 and proven in 2002 by Preda Mihăilescu at Paderborn University. The integers 23 and 32 are ...

. * the order of the smallest non-abelian group all of whose subgroups are normal. * the dimension of the

octonion In mathematics, the octonions are a normed division algebra over the real numbers, a kind of hypercomplex number system. The octonions are usually represented by the capital letter O, using boldface or blackboard bold \mathbb O. Octonions hav ...

s and is the highest possible dimension of a

normed division algebra In mathematics, Hurwitz's theorem is a theorem of Adolf Hurwitz (1859–1919), published posthumously in 1923, solving the Hurwitz problem for finite-dimensional unital real non-associative algebras endowed with a positive-definite quadratic f ...

. * the first number to be the aliquot sum of two numbers other than itself; the discrete biprime , and the square number . A number is divisible by 8 if its last three digits, when written in decimal, are also divisible by 8, or its last three digits are 0 when written in

binary Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that ta ...

. A

polygon In geometry, a polygon () is a plane figure that is described by a finite number of straight line segments connected to form a closed ''polygonal chain'' (or ''polygonal circuit''). The bounded plane region, the bounding circuit, or the two to ...

with eight sides is an octagon. The sides and

span Span may refer to: Science, technology and engineering * Span (unit), the width of a human hand * Span (engineering), a section between two intermediate supports * Wingspan, the distance between the wingtips of a bird or aircraft * Sorbitan ester ...

of a

regular octagon In geometry, an octagon (from the Greek ὀκτάγωνον ''oktágōnon'', "eight angles") is an eight-sided polygon or 8-gon. A '' regular octagon'' has Schläfli symbol and can also be constructed as a quasiregular truncated square, t, whi ...

, or truncated

square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...

, are in

silver ratio In mathematics, two quantities are in the silver ratio (or silver mean) if the ratio of the smaller of those two quantities to the larger quantity is the same as the ratio of the larger quantity to the sum of the smaller quantity and twice t ...

, and its circumscribing

has a side and diagonal length ratio of ; with both the silver ratio and the

square root of two The square root of 2 (approximately 1.4142) is a positive real number that, when multiplied by itself, equals the number 2. It may be written in mathematics as \sqrt or 2^, and is an algebraic number. Technically, it should be called the princi ...

intimately interconnected through

Pell number In mathematics, the Pell numbers are an infinite sequence of integers, known since ancient times, that comprise the denominators of the closest rational approximations to the square root of 2. This sequence of approximations begins , , , , an ...

s, where in particular the quotient of successive Pell numbers generates rational approximations for coordinates of a

. With a

central angle A central angle is an angle whose apex (vertex) is the center O of a circle and whose legs (sides) are radii intersecting the circle in two distinct points A and B. Central angles are subtended by an arc between those two points, and the arc le ...

of 45 degrees and an

internal angle In geometry, an angle of a polygon is formed by two sides of the polygon that share an endpoint. For a simple (non-self-intersecting) polygon, regardless of whether it is convex or non-convex, this angle is called an interior angle (or ) if ...

of 135 degrees, regular octagons are able to

tessellate A tessellation or tiling is the covering of a surface, often a plane, using one or more geometric shapes, called ''tiles'', with no overlaps and no gaps. In mathematics, tessellation can be generalized to higher dimensions and a variety of ...

two-dimensional space alongside squares in the

truncated square tiling In geometry, the truncated square tiling is a semiregular tiling, semiregular tiling by regular polygons of the Euclidean plane with one square (geometry), square and two octagons on each vertex (geometry), vertex. This is the only edge-to-edge ti ...

, as well as fill a plane-vertex with a regular

triangle A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry. A triangle with vertices ''A'', ''B'', and ''C'' is denoted \triangle ABC. In Euclidean geometry, any three points, when non- colline ...

and a regular

icositetragon In geometry, an icositetragon (or icosikaitetragon) or 24-gon is a twenty-four-sided polygon. The sum of any icositetragon's interior angles is 3960 degrees. Regular icositetragon The '' regular icositetragon'' is represented by Schläfli symbol ...

. The

Ammann–Beenker tiling In geometry, an Ammann–Beenker tiling is a nonperiodic tiling which can be generated either by an aperiodic set of prototiles as done by Robert Ammann in the 1970s, or by the cut-and-project method as done independently by F. P. M. Beenker. Th ...

is a nonperiodic tesselation of

prototile In the mathematical theory of tessellations, a prototile is one of the shapes of a tile in a tessellation. Definition A tessellation of the plane or of any other space is a cover of the space by closed shapes, called tiles, that have disjoint in ...

s that feature prominent octagonal ''silver'' eightfold symmetry, and is the two-dimensional

orthogonal projection In linear algebra and functional analysis, a projection is a linear transformation P from a vector space to itself (an endomorphism) such that P\circ P=P. That is, whenever P is applied twice to any vector, it gives the same result as if it wer ...

of the 8-8 duoprism. In number theory,

figurate number The term figurate number is used by different writers for members of different sets of numbers, generalizing from triangular numbers to different shapes (polygonal numbers) and different dimensions (polyhedral numbers). The term can mean * polyg ...

s representing octagons are called

octagonal number An octagonal number is a figurate number that represents an octagon. The octagonal number for ''n'' is given by the formula 3''n''2 - 2''n'', with ''n'' > 0. The first few octagonal numbers are : 1, 8, 21, 40, 65, 96, 133, 176, 225, 280, 34 ...

s. A cube is a

regular polyhedron A regular polyhedron is a polyhedron whose symmetry group acts transitively on its flags. A regular polyhedron is highly symmetrical, being all of edge-transitive, vertex-transitive and face-transitive. In classical contexts, many different equival ...

with eight vertices that also forms the

cubic honeycomb The cubic honeycomb or cubic cellulation is the only proper regular space-filling tessellation (or honeycomb) in Euclidean 3-space made up of cubic cells. It has 4 cubes around every edge, and 8 cubes around each vertex. Its vertex figure is a r ...

, the only regular honeycomb in three-dimensional space. Through various truncation operations, the

generates eight other convex uniform honeycombs under the group

_3

. The

octahedron In geometry, an octahedron (plural: octahedra, octahedrons) is a polyhedron with eight faces. The term is most commonly used to refer to the regular octahedron, a Platonic solid composed of eight equilateral triangles, four of which meet at ea ...

, with eight

equilateral triangle In geometry, an equilateral triangle is a triangle in which all three sides have the same length. In the familiar Euclidean geometry, an equilateral triangle is also equiangular; that is, all three internal angles are also congruent to each oth ...

s as

faces The face is the front of an animal's head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may affe ...

, is the

dual polyhedron In geometry, every polyhedron is associated with a second dual structure, where the vertices of one correspond to the faces of the other, and the edges between pairs of vertices of one correspond to the edges between pairs of faces of the other. ...

to the cube and one of eight convex deltahedra. The

stella octangula The stellated octahedron is the only stellation of the octahedron. It is also called the stella octangula (Latin for "eight-pointed star"), a name given to it by Johannes Kepler in 1609, though it was known to earlier geometers. It was depict ...

, or ''eight-pointed star'', is the only stellation with

octahedral symmetry A regular octahedron has 24 rotational (or orientation-preserving) symmetries, and 48 symmetries altogether. These include transformations that combine a reflection and a rotation. A cube has the same set of symmetries, since it is the polyhedr ...

. It has eight triangular faces alongside eight vertices that form a cubic

faceting Stella octangula as a faceting of the cube In geometry, faceting (also spelled facetting) is the process of removing parts of a polygon, polyhedron or polytope, without creating any new vertices. New edges of a faceted polyhedron may be cre ...

, composed of two self-dual

tetrahedra In geometry, a tetrahedron (plural: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular faces, six straight edges, and four vertex corners. The tetrahedron is the simplest of all the o ...

that makes it the simplest of five regular compound polyhedra. The

cuboctahedron A cuboctahedron is a polyhedron with 8 triangular faces and 6 square faces. A cuboctahedron has 12 identical vertices, with 2 triangles and 2 squares meeting at each, and 24 identical edges, each separating a triangle from a square. As such, it ...

, on the other hand, is a rectified cube or rectified octahedron, and one of only two convex quasiregular polyhedra. It contains eight equilateral triangular faces alongside six squares, whose first stellation is the cube-octahedron compound. The

hexagonal prism In geometry, the hexagonal prism is a prism with hexagonal base. Prisms are polyhedrons; this polyhedron has 8 faces, 18 edges, and 12 vertices.. Since it has 8 faces, it is an octahedron. However, the term ''octahedron'' is primarily used ...

, which classifies as an irregular octahedron that is a

parallelohedron In geometry, a parallelohedron is a polyhedron that can be translated without rotations in 3-dimensional Euclidean space to fill space with a honeycomb in which all copies of the polyhedron meet face-to-face. There are five types of parallelohedr ...

, like the cube, is able to

space as a three-dimensional analogue of the

hexagon In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A '' regular hexagon'' has ...

. The

gyrobifastigium In geometry, the gyrobifastigium is the 26th Johnson solid (). It can be constructed by joining two face-regular triangular prisms along corresponding square faces, giving a quarter-turn to one prism. It is the only Johnson solid that can tile ...

, with four square faces and four triangular faces, is the only Johnson solid that is able to tessellate space, while the

truncated octahedron In geometry, the truncated octahedron is the Archimedean solid that arises from a regular octahedron by removing six pyramids, one at each of the octahedron's vertices. The truncated octahedron has 14 faces (8 regular hexagons and 6 squares), 36 ...

, also a parallelohedron, is the

permutohedron In mathematics, the permutohedron of order ''n'' is an (''n'' − 1)-dimensional polytope embedded in an ''n''-dimensional space. Its vertex coordinates (labels) are the permutations of the first ''n'' natural numbers. The edges ident ...

of order four, with eight hexagonal faces alongside six squares that is likewise the only Archimedean solid that can generate a

honeycomb A honeycomb is a mass of hexagonal prismatic wax cells built by honey bees in their nests to contain their larvae and stores of honey and pollen. Beekeepers may remove the entire honeycomb to harvest honey. Honey bees consume about of honey ...

on its own.

Vertex-transitive In geometry, a polytope (e.g. a polygon or polyhedron) or a tiling is isogonal or vertex-transitive if all its vertices are equivalent under the symmetries of the figure. This implies that each vertex is surrounded by the same kinds of face in ...

semiregular polytope In geometry, by Thorold Gosset's definition a semiregular polytope is usually taken to be a polytope that is vertex-transitive and has all its facets being regular polytopes. E.L. Elte compiled a longer list in 1912 as ''The Semiregular Polyt ...

s whose

facets A facet is a flat surface of a geometric shape, e.g., of a cut gemstone. Facet may also refer to: Arts, entertainment, and media * ''Facets'' (album), an album by Jim Croce * ''Facets'', a 1980 album by jazz pianist Monty Alexander and his tri ...

are ''finite'' exist up through the 8th dimension. In the third dimension, they include the

Archimedean solids In geometry, an Archimedean solid is one of the 13 solids first enumerated by Archimedes. They are the convex uniform polyhedra composed of regular polygons meeting in identical vertices, excluding the five Platonic solids (which are compose ...

and the infinite family of uniform prisms and

antiprism In geometry, an antiprism or is a polyhedron composed of two parallel direct copies (not mirror images) of an polygon, connected by an alternating band of triangles. They are represented by the Conway notation . Antiprisms are a subclass o ...

s, while in the fourth dimension, only the

rectified 5-cell In four-dimensional geometry, the rectified 5-cell is a uniform 4-polytope composed of 5 regular tetrahedral and 5 regular octahedral cells. Each edge has one tetrahedron and two octahedra. Each vertex has two tetrahedra and three octahedra. In t ...

, the

rectified 600-cell In geometry, the rectified 600-cell or rectified hexacosichoron is a convex uniform 4-polytope composed of 600 regular octahedra and 120 icosahedra cells. Each edge has two octahedra and one icosahedron. Each vertex has five octahedra and two icos ...

, and the

snub 24-cell In geometry, the snub 24-cell or snub disicositetrachoron is a convex uniform 4-polytope composed of 120 regular tetrahedral and 24 icosahedral cells. Five tetrahedra and three icosahedra meet at each vertex. In total it has 480 triangular faces ...

are semiregular polytopes. For dimensions

five 5 is a number, numeral, and glyph. 5, five or number 5 may also refer to: * AD 5, the fifth year of the AD era * 5 BC, the fifth year before the AD era Literature * ''5'' (visual novel), a 2008 visual novel by Ram * ''5'' (comics), an awa ...

through eight, the

demipenteract In five-dimensional geometry, a demipenteract or 5-demicube is a semiregular 5-polytope, constructed from a ''5-hypercube'' ( penteract) with alternated vertices removed. It was discovered by Thorold Gosset. Since it was the only semiregular 5 ...

and the k₂₁ polytopes 2₂₁, 3₂₁, and 4₂₁ are the only semiregular ( Gosset) polytopes. Collectively, the k₂₁ family of polytopes contains eight figures that are rooted in the

triangular prism In geometry, a triangular prism is a three-sided prism; it is a polyhedron made of a triangular base, a translated copy, and 3 faces joining corresponding sides. A right triangular prism has rectangular sides, otherwise it is ''oblique''. A ...

, which is the simplest semiregular polytope that is made of three cubes and two equilateral triangles. It also includes one of only three semiregular Euclidean honeycombs: the

affine Affine may describe any of various topics concerned with connections or affinities. It may refer to: * Affine, a relative by marriage in law and anthropology * Affine cipher, a special case of the more general substitution cipher * Affine comb ...

5₂₁ honeycomb that represents the arrangement of vertices of the eight-dimensional

\mathrm E_

lattice, and made of 4₂₁

. The culminating figure is the ninth-dimensional 6₂₁ honeycomb, which is the only affine semiregular

paracompact In mathematics, a paracompact space is a topological space in which every open cover has an open refinement that is locally finite. These spaces were introduced by . Every compact space is paracompact. Every paracompact Hausdorff space is normal ...

hyperbolic Hyperbolic is an adjective describing something that resembles or pertains to a hyperbola (a curve), to hyperbole (an overstatement or exaggeration), or to hyperbolic geometry. The following phenomena are described as ''hyperbolic'' because they ...

honeycomb with infinite facets and

vertex figure In geometry, a vertex figure, broadly speaking, is the figure exposed when a corner of a polyhedron or polytope is sliced off. Definitions Take some corner or vertex of a polyhedron. Mark a point somewhere along each connected edge. Draw line ...

s in the k₂₁ family. There are no other finite semiregular polytopes or honeycombs in dimensions ''n'' > 8.

Sphenic number In number theory, a sphenic number (from grc, σφήνα, 'wedge') is a positive integer that is the product of three distinct prime numbers. Because there are infinitely many prime numbers, there are also infinitely many sphenic numbers. Definit ...

s always have exactly eight divisors. The number 8 is involved with a number of interesting mathematical phenomena related to the notion of

Bott periodicity In mathematics, the Bott periodicity theorem describes a periodicity in the homotopy groups of classical groups, discovered by , which proved to be of foundational significance for much further research, in particular in K-theory of stable comp ...

. If

O(\infty)

is the direct limit of the inclusions of real orthogonal groups

O(1)\hookrightarrow O(2)\hookrightarrow\ldots\hookrightarrow O(k)\hookrightarrow\ldots

, the following holds: :

\pi_(O(\infty))\cong\pi_(O(\infty))

. Clifford algebras also display a periodicity of 8. For example, the algebra ''Cl''(''p'' + 8,''q'') is isomorphic to the algebra of 16 by 16 matrices with entries in ''Cl''(''p'',''q''). We also see a period of 8 in the

K-theory In mathematics, K-theory is, roughly speaking, the study of a ring generated by vector bundles over a topological space or scheme. In algebraic topology, it is a cohomology theory known as topological K-theory. In algebra and algebraic geometr ...

of spheres and in the

representation theory Representation theory is a branch of mathematics that studies abstract algebraic structures by ''representing'' their elements as linear transformations of vector spaces, and studies modules over these abstract algebraic structures. In essen ...

of the rotation groups, the latter giving rise to the 8 by 8

spinor In geometry and physics, spinors are elements of a complex vector space that can be associated with Euclidean space. Like geometric vectors and more general tensors, spinors transform linearly when the Euclidean space is subjected to a sligh ...

ial chessboard. All of these properties are closely related to the properties of the

s. The

spin group In mathematics the spin group Spin(''n'') page 15 is the double cover of the special orthogonal group , such that there exists a short exact sequence of Lie groups (when ) :1 \to \mathrm_2 \to \operatorname(n) \to \operatorname(n) \to 1. As a ...

Spin(8) is the unique such group that exhibits the phenomenon of

triality In mathematics, triality is a relationship among three vector spaces, analogous to the duality relation between dual vector spaces. Most commonly, it describes those special features of the Dynkin diagram D4 and the associated Lie group Spin( ...

. The lowest-dimensional even

unimodular lattice In geometry and mathematical group theory, a unimodular lattice is an integral lattice of determinant 1 or −1. For a lattice in ''n''-dimensional Euclidean space, this is equivalent to requiring that the volume of any fundamen ...

is the 8-dimensional

\mathrm E_

lattice. Even positive definite unimodular lattices exist only in dimensions divisible by 8. A figure 8 is the common name of a geometric

shape A shape or figure is a graphical representation of an object or its external boundary, outline, or external surface, as opposed to other properties such as color, texture, or material type. A plane shape or plane figure is constrained to lie ...

, often used in the context of sports, such as skating. Figure-eight turns of a rope or cable around a cleat, pin, or bitt are used to belay something.

List of basic calculations

Etymology

English ''eight'', from Old English ''eahta, æhta'',

Proto-Germanic Proto-Germanic (abbreviated PGmc; also called Common Germanic) is the reconstructed proto-language of the Germanic branch of the Indo-European languages. Proto-Germanic eventually developed from pre-Proto-Germanic into three Germanic bran ...

''*ahto'' is a direct continuation of

Proto-Indo-European Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. Its proposed features have been derived by linguistic reconstruction from documented Indo-European languages. No direct record of Proto-Indo- ...

'' *oḱtṓ(w)-'', and as such cognate with Greek and Latin ''octo-'', both of which stems are reflected by the English prefix oct(o)-, as in the ordinal adjective ''octaval'' or ''octavary'', the distributive adjective is ''

octonary : ''For the base-8 numeral system, see octal.'' An octonary is an eight-line section in a poem, song or psalm. The most notable example is found in Psalm 119Calvin ''Bible Commentaries: Psalms, Part IV'' p287 "Some call this the octonary psalm, bec ...

''. The adjective ''octuple'' (Latin ''octu-plus'') may also be used as a noun, meaning "a set of eight items"; the diminutive ''

octuplet A multiple birth is the culmination of one multiple pregnancy, wherein the mother gives birth to two or more babies. A term most applicable to vertebrate species, multiple births occur in most kinds of mammals, with varying frequencies. Such bir ...

'' is mostly used to refer to eight siblings delivered in one birth. The Semitic numeral is based on a root ''*θmn-'', whence Akkadian ''smn-'', Arabic ''ṯmn-'', Hebrew ''šmn-'' etc. The

Chinese numeral Chinese numerals are words and characters used to denote numbers in Chinese. Today, speakers of Chinese use three written numeral systems: the system of Arabic numerals used worldwide, and two indigenous systems. The more familiar indigenous ...

, written (

Mandarin Mandarin or The Mandarin may refer to: Language * Mandarin Chinese, branch of Chinese originally spoken in northern parts of the country ** Standard Chinese or Modern Standard Mandarin, the official language of China ** Taiwanese Mandarin, Stand ...

: ''bā'';

Cantonese Cantonese ( zh, t=廣東話, s=广东话, first=t, cy=Gwóngdūng wá) is a language within the Chinese (Sinitic) branch of the Sino-Tibetan languages originating from the city of Guangzhou (historically known as Canton) and its surrounding ar ...

: ''baat''), is from

Old Chinese Old Chinese, also called Archaic Chinese in older works, is the oldest attested stage of Chinese, and the ancestor of all modern varieties of Chinese. The earliest examples of Chinese are divinatory inscriptions on oracle bones from around 1250 ...

''*priāt-'', ultimately from Sino-Tibetan ''b-r-gyat'' or ''b-g-ryat'' which also yielded Tibetan '' brgyat''. It has been argued that, as the

cardinal number In mathematics, cardinal numbers, or cardinals for short, are a generalization of the natural numbers used to measure the cardinality (size) of sets. The cardinality of a finite set is a natural number: the number of elements in the set. T ...

is the highest number of items that can universally be cognitively processed as a single set, the etymology of the numeral ''eight'' might be the first to be considered composite, either as "twice four" or as "two short of ten", or similar. The Turkic words for "eight" are from a

Proto-Turkic Proto-Turkic is the linguistic reconstruction of the common ancestor of the Turkic languages that was spoken by the Proto-Turks before their divergence into the various Turkic peoples. Proto-Turkic separated into Oghur (western) and Common Turk ...

stem ''*sekiz'', which has been suggested as originating as a negation of ''eki'' "two", as in "without two fingers" (i.e., "two short of ten; two fingers are not being held up"); this same principle is found in Finnic '' *kakte-ksa'', which conveys a meaning of "two before (ten)". The Proto-Indo-European reconstruction '' *oḱtṓ(w)-'' itself has been argued as representing an old dual, which would correspond to an original meaning of "twice four". Proponents of this "quaternary hypothesis" adduce the numeral ', which might be built on the stem ''new-'', meaning "new" (indicating the beginning of a "new set of numerals" after having counted to eight).

Evolution of the Arabic digit

The modern digit 8, like all modern Arabic numerals other than zero, originates with the

Brahmi numerals The Brahmi numerals are a numeral system attested from the 3rd century BCE (somewhat later in the case of most of the tens). They are a non positional decimal system. They are the direct graphic ancestors of the modern Hindu–Arabic numeral s ...

. The Brahmi digit for ''eight'' by the 1st century was written in one stroke as a curve └┐ looking like an uppercase H with the bottom half of the left line and the upper half of the right line removed. However, the digit for eight used in India in the early centuries of the Common Era developed considerable graphic variation, and in some cases took the shape of a single wedge, which was adopted into the Perso-Arabic tradition as ٨ (and also gave rise to the later Devanagari form ८); the alternative curved glyph also existed as a variant in Perso-Arabic tradition, where it came to look similar to our digit 5. The digits as used in

Al-Andalus Al-Andalus translit. ; an, al-Andalus; ast, al-Ándalus; eu, al-Andalus; ber, ⴰⵏⴷⴰⵍⵓⵙ, label= Berber, translit=Andalus; ca, al-Àndalus; gl, al-Andalus; oc, Al Andalús; pt, al-Ândalus; es, al-Ándalus () was the M ...

by the 10th century were a distinctive western variant of the glyphs used in the Arabic-speaking world, known as ''ghubār'' numerals (''ghubār'' translating to "

sand table A sand table uses constrained sand for modelling or educational purposes. The original version of a sand table may be the abax used by early Greek students. In the modern era, one common use for a sand table is to make terrain models for milit ...

"). In these digits, the line of the ''5''-like glyph used in Indian manuscripts for eight came to be formed in ghubār as a closed loop, which was the ''8''-shape that became adopted into European use in the 10th century. Just as in most modern

typeface A typeface (or font family) is the design of lettering that can include variations in size, weight (e.g. bold), slope (e.g. italic), width (e.g. condensed), and so on. Each of these variations of the typeface is a font. There are thousands o ...

s, in typefaces with

text figures Text figures (also known as non-lining, lowercase, old style, ranging, hanging, medieval, billing, or antique figures or numerals) are numerals designed with varying heights in a fashion that resembles a typical line of running text, hence the ...

the character for the digit 8 usually has an ascender, as, for example, in . The

infinity symbol The infinity symbol (\infty) is a mathematical symbol representing the concept of infinity. This symbol is also called a lemniscate, after the lemniscate curves of a similar shape studied in algebraic geometry, or "lazy eight", in the terminol ...

∞, described as a "sideways figure eight", is unrelated to the digit 8 in origin; it is first used (in the mathematical meaning "infinity") in the 17th century, and it may be derived from the

Roman numeral Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, ea ...

for "one thousand" CIƆ, or alternatively from the final Greek letter, ω.

In science

Physics

* In nuclear physics, the second magic number. * In

particle physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) an ...

, the eightfold way is used to classify sub-atomic particles. * In statistical mechanics, the

eight-vertex model In statistical mechanics, the eight-vertex model is a generalisation of the ice-type (six-vertex) models; it was discussed by Sutherland, and Fan & Wu, and solved by Baxter in the zero-field case. Description As with the ice-type models, the ei ...

has 8 possible configurations of arrows at each vertex.

Astronomy

Messier object The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his ''Catalogue des Nébuleuses et des Amas d'Étoiles'' (''Catalogue of Nebulae and Star Clusters''). Because Messier was only in ...

M8, a magnitude 5.0 nebula in the constellation of Sagittarius. * The New General Cataloguebr>object

NGC 8 NGC 8 is an asterism of two completely unrelated stars (spectral types K6I and G4) in the constellation Pegasus, discovered on 29 September 1865 by Otto Wilhelm von Struve. It is approximately 2.7 arc minutes away from NGC 9. The two sta ...

, a double star in the constellation Pegasus. * Since the demotion of

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest ...

to a

dwarf planet A dwarf planet is a small planetary-mass object that is in direct orbit of the Sun, smaller than any of the eight classical planets but still a world in its own right. The prototypical dwarf planet is Pluto. The interest of dwarf planets to ...

on 24 August 2006, in our

Solar System The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...

, eight of the bodies orbiting the Sun are considered to be

planet A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a you ...

Chemistry

* The

atomic number The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei, this is equal to the proton number (''n''p) or the number of protons found in the nucleus of every ...

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

. * The most stable allotrope of a sulfur molecule is made of eight sulfur atoms arranged in a rhombic form. * The maximum number of electrons that can occupy a

valence shell In chemistry and physics, a valence electron is an electron in the outer shell associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed. In a single covalent bond, a shared pair forms ...

. * The red pigment

lycopene Lycopene is an organic compound classified as a tetraterpene and a carotene. Lycopene (from the neo-Latin '' Lycopersicum'', the tomato species) is a bright red carotenoid hydrocarbon found in tomatoes and other red fruits and vegetables. Occu ...

consists of eight isoprene units.

Geology

* A

disphenoid In geometry, a disphenoid () is a tetrahedron whose four faces are congruent acute-angled triangles. It can also be described as a tetrahedron in which every two edges that are opposite each other have equal lengths. Other names for the same sh ...

crystal is bounded by eight scalene triangles arranged in pairs. A ditetragonal prism in the

tetragonal crystal system In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a squa ...

has eight similar faces whose alternate interfacial angles only are equal.

Biology

* All

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

s, and more generally all

arachnid Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegar ...

s, have eight legs.

Orb-weaver spider Orb-weaver spiders are members of the spider family (biology), family Araneidae. They are the most common group of builders of spiral wheel-shaped spider web, webs often found in gardens, fields, and forests. The English word "orb" can mean "circ ...

s of the cosmopolitan family Areneidae have eight similar eyes. * The octopus and its cephalopod relatives in genus ''Argonauta'' have eight arms (tentacles). * Compound coelenterates of the subclass or order Alcyonaria have polyps with eight-branched tentacles and eight septa. * Sea anemones of genus ''

Edwardsia ''Edwardsia'' is a genus of sea anemones, the type of the family Edwardsiidae. They have eight mesenteries and live in tubes in the sand. The name, in New Latin, commemorates the French zoologist Henri Milne-Edwards Henri Milne-Edwards (23 O ...

'' have eight

mesenteries In zoology, a mesentery is a membrane inside the body cavity of an animal. The term identifies different structures in different phyla: in vertebrates it is a double fold of the peritoneum enclosing the intestines; in other organisms it forms com ...

. * Animals of phylum

Ctenophora Ctenophora (; ctenophore ; ) comprise a phylum of marine invertebrates, commonly known as comb jellies, that inhabit sea waters worldwide. They are notable for the groups of cilia they use for swimming (commonly referred to as "combs"), and ...

swim by means of eight meridional bands of transverse ciliated plates, each plate representing a row of large modified cilia. * The eight-spotted forester (genus ''Alypia'', family

Zygaenidae The Zygaenidae moths are a family of Lepidoptera. The majority of zygaenids are tropical, but they are nevertheless quite well represented in temperate regions. Some of the 1000 or so species are commonly known as burnet or forester moths, oft ...

) is a diurnal moth having black wings with brilliant white spots. * The ascus in fungi of the class Ascomycetes, following nuclear fusion, bears within it typically eight ascospores. * Herbs of genus ''

Coreopsis ''Coreopsis'' () is a genus of flowering plants in the family Asteraceae. Common names include calliopsis and tickseed, a name shared with various other plants. Description These plants range from in height. The flowers are usually yellow wi ...

'' (tickseed) have showy flower heads with involucral bracts in two distinct series of eight each. * In human

adult dentition Permanent teeth or adult teeth are the second set of teeth formed in diphyodont mammals. In humans and old world simians, there are thirty-two permanent teeth, consisting of six maxillary and six mandibular molars, four maxillary and four mandibu ...

there are eight teeth in each quadrant. The eighth tooth is the so-called

wisdom tooth A third molar, commonly called wisdom tooth, is one of the three molars per quadrant of the human dentition. It is the most posterior of the three. The age at which wisdom teeth come through ( erupt) is variable, but this generally occurs betw ...

. * There are eight

cervical nerves A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the ...

on each side in man and most mammals.

Psychology

* There are eight

Jungian cognitive functions Cognitive functions, also referred to as psychological functions, as described by Carl Jung in his book '' Psychological Types'', are particular mental processes within a person's psyche that are present regardless of common circumstance. This is a ...

, according to the MBTI models by

John Beebe John Beebe (born June 24, 1939) is an American psychiatrist and Jungian analyst in practice in San Francisco. Beebe was born in Washington, D.C. He received degrees from Harvard College and the University of Chicago medical school. He is a pas ...

and

Linda Berens Linda may refer to: As a name * Linda (given name), a female given name (including a list of people and fictional characters so named) * Linda (singer) (born 1977), stage name of Svetlana Geiman, a Russian singer * Anita Linda (born Alice Lake ...

. *

Timothy Leary Timothy Francis Leary (October 22, 1920 – May 31, 1996) was an American psychologist and author known for his strong advocacy of psychedelic drugs. Evaluations of Leary are polarized, ranging from bold oracle to publicity hound. He was "a her ...

identified a hierarchy of eight levels of consciousness.

In technology

* A

is eight

s. * Many (mostly historic) computer architectures are eight-bit, among them the Nintendo Entertainment System. * Standard-8 and Super-8 are 8 mm

film formats A film format is a technical definition of a set of standard characteristics regarding image capture on photographic film for still images or film stock for filmmaking. It can also apply to projected film, either slides or movies. The primary ...

. * Video8, Hi8 and Digital8 are related 8 mm video formats. * On most phones, the 8 key is associated with the letters T, U, and V, but on the BlackBerry Pearl it is the key for B and N. * An eight may refer to an eight-cylinder engine or automobile. A

V8 engine A V8 engine is an eight-cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration. The first V8 engine was produced by the French Antoinette company in 1904, developed and u ...

is an

internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal c ...

with eight cylinders configured in two banks (rows) of four forming a "V" when seen from the end. * A

figure-eight knot The figure-eight knot or figure-of-eight knot is a type of stopper knot. It is very important in both sailing and rock climbing as a method of stopping ropes from running out of retaining devices. Like the overhand knot, which will jam under st ...

(so named for its configuration) is a kind of

stopper knot Stopper may refer to: * Bung, a plug used to stop the opening of a container ** Laboratory rubber stopper, a specific type of bung * Plug (sanitation), used to stop a drainage outlet * Defender (association football), in soccer (association foo ...

. * The number eight written in parentheses is the code for the musical note in

Windows Live Messenger MSN Messenger (also known colloquially simply as "Messenger"), later rebranded as Windows Live Messenger, was a cross-platform instant-messaging client developed by Microsoft. It connected to the Microsoft Messenger service and, in later versio ...

. * In a

seven-segment display A seven-segment display is a form of electronic display device for displaying decimal numerals that is an alternative to the more complex dot matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, basic ...

, when an 8 is illuminated, all the display bulbs are on.

In measurement

* The SI prefix for 1000⁸ is yotta (Y), and for its reciprocal, yocto (y). * In liquid measurement ( United States customary units), there are eight

fluid ounce A fluid ounce (abbreviated fl oz, fl. oz. or oz. fl., old forms ℥, fl ℥, f℥, ƒ ℥) is a unit of volume (also called ''capacity'') typically used for measuring liquids. The British Imperial, the United States customary, and the United ...

s in a

cup A cup is an open-top used to hold hot or cold liquids for pouring or drinking; while mainly used for drinking, it also can be used to store solids for pouring (e.g., sugar, flour, grains, salt). Cups may be made of glass, metal, china, clay, ...

, eight

pint The pint (, ; symbol pt, sometimes abbreviated as ''p'') is a unit of volume or capacity in both the imperial and United States customary measurement systems. In both of those systems it is traditionally one eighth of a gallon. The British impe ...

s in a

gallon The gallon is a unit of volume in imperial units and United States customary units. Three different versions are in current use: *the imperial gallon (imp gal), defined as , which is or was used in the United Kingdom, Ireland, Canada, Austr ...

and eight

tablespoon A tablespoon (tbsp. , Tbsp. , Tb. , or T.) is a large spoon. In many English-speaking regions, the term now refers to a large spoon used for serving; however, in some regions, it is the largest type of spoon used for eating. By extension, the ter ...

fuls in a

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

. * There are eight

furlong A furlong is a measure of distance in imperial units and United States customary units equal to one eighth of a mile, equivalent to 660 feet, 220 yards, 40 rods, 10 chains or approximately 201 metres. It is now mostly confined to use in hor ...

s in a mile. * The clove, an old

English unit English units are the units of measurement used in England up to 1826 (when they were replaced by Imperial units), which evolved as a combination of the Anglo-Saxon and Roman systems of units. Various standards have applied to English units at d ...

of weight, was equal to eight pounds when measuring cheese. * An eight may be an article of clothing of the eighth

size Size in general is the magnitude or dimensions of a thing. More specifically, ''geometrical size'' (or ''spatial size'') can refer to linear dimensions ( length, width, height, diameter, perimeter), area, or volume. Size can also be m ...

. * Force eight is the first

wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ho ...

strength attributed to a

gale A gale is a strong wind; the word is typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as sustained surface winds moving at a speed of between 34 and 47 knots (, or ).Beaufort scale when announced on a

Shipping Forecast The Shipping Forecast is a BBC Radio broadcast of weather reports and forecasts for the seas around the coasts of the British Isles. It is produced by the Met Office and broadcast by BBC Radio 4 on behalf of the Maritime and Coastguard Agency. ...

In culture

Currency

* Sailors and civilians alike from the 1500s onward referred to evenly divided parts of the

Spanish dollar The Spanish dollar, also known as the piece of eight ( es, Real de a ocho, , , or ), is a silver coin of approximately diameter worth eight Spanish reales. It was minted in the Spanish Empire following a monetary reform in 1497 with content ...

as "pieces of eight", or "bits".

Architecture

* Various types of buildings are usually eight-sided (octagonal), such as single-roomed

gazebo A gazebo is a pavilion structure, sometimes octagonal or turret-shaped, often built in a park, garden or spacious public area. Some are used on occasions as bandstands. Etymology The etymology given by Oxford Dictionaries is "Mid 18th c ...

s and multi-roomed

pagoda A pagoda is an Asian tiered tower with multiple eaves common to Nepal, India, China, Japan, Korea, Myanmar, Vietnam, and other parts of Asia. Most pagodas were built to have a religious function, most often Buddhist but sometimes Taoist, ...

s (descended from stupas; see religion section below). * Eight caulicoles rise out of the leafage in a

Corinthian capital The Corinthian order (Greek: Κορινθιακός ρυθμός, Latin: ''Ordo Corinthius'') is the last developed of the three principal classical orders of Ancient Greek architecture and Roman architecture. The other two are the Doric order w ...

, ending in leaves that support the

volutes A volute is a spiral, scroll-like ornament that forms the basis of the Ionic order, found in the capital of the Ionic column. It was later incorporated into Corinthian order and Composite column capitals. Four are normally to be found on an ...

In religion, folk belief and divination

Hinduism

* Also known as Ashtha, Aṣṭa, or Ashta in

Sanskrit Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...

, it is the number of wealth and abundance. * The goddess of wealth and prosperity,

Lakshmi Lakshmi (; , sometimes spelled Laxmi, ), also known as Shri (, ), is one of the principal goddesses in Hinduism. She is the goddess of wealth, fortune, power, beauty, fertility and prosperity, and associated with ''Maya'' ("Illusion"). Alo ...

, has eight forms known as

Ashta Lakshmi Ashta Lakshmi ( Sanskrit: अष्टलक्ष्मी, IAST: Aṣṭalakṣmī; lit. "Octet of Lakshmi") or Ashtalakshmi, is a group of the eight manifestations of Lakshmi, the Hindu goddess of prosperity. She presides over eight sources o ...

and worshipped as:
"''Maha-lakshmi, Dhana-lakshmi, Dhanya-lakshmi, Gaja-lakshmi,
Santana-lakshmi, Veera-lakshmi, Vijaya-lakshmi and Vidhya-lakshmi''" *There are eight ''nidhi'', or seats of wealth, according to

Hinduism Hinduism () is an Indian religion or '' dharma'', a religious and universal order or way of life by which followers abide. As a religion, it is the world's third-largest, with over 1.2–1.35 billion followers, or 15–16% of the global p ...

. *There are eight

guardians of the directions The Guardians of the Directions (Sanskrit: दिक्पाल, Dikpāla) are the deities who rule the specific directions of space according to Hinduism, Jainism and '' '' Buddhism—especially . As a group of eight deities, they are called ( ...

known as ''Astha-dikpalas''. *There are eight

Hindu Hindus (; ) are people who religiously adhere to Hinduism. Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pages 35–37 Historically, the term has also been used as a geographical, cultural, and later religious identifier for ...

monasteries established by the saint

Madhvacharya Madhvacharya (; ; CE 1199-1278 or CE 1238–1317), sometimes anglicised as Madhva Acharya, and also known as Purna Prajna () and Ānanda Tīrtha, was an Indian philosopher, theologian and the chief proponent of the '' Dvaita'' (dualism) sch ...

Udupi Udupi (alternate spelling Udipi; also known as Odipu) is a city in the Indian state of Karnataka. Udupi is situated about north of the educational, commercial and industrial hub of Mangalore and about west of state capital Bangalore by road. ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

popularly known as the ''

Ashta Mathas of Udupi The Tulu Ashta Mathas of Udupi ( kn, ಉಡುಪಿಯ ತುಳು ಅಷ್ಟ ಮಠಗಳು) are a group of eight ''mathas'' or Hindu monasteries established by Madhvacharya, the preceptor of the Dvaita school of Hindu thought with his d ...

''.

Buddhism

* The

Dharmacakra The dharmachakra (Sanskrit: धर्मचक्र; Pali: ''dhammacakka'') or wheel of dharma is a widespread symbol used in Indian religions such as Hinduism, Jainism, and especially Buddhism.John C. Huntington, Dina Bangdel, ''The Circle o ...

, a

Buddhist Buddhism ( , ), also known as Buddha Dharma and Dharmavinaya (), is an Indian religion or philosophical tradition based on teachings attributed to the Buddha. It originated in northern India as a -movement in the 5th century BCE, and ...

symbol, has eight spokes. The Buddha's principal teaching—the Four Noble Truths—ramifies as the

Noble Eightfold Path The Noble Eightfold Path (Pali: ; Sanskrit: ) is an early summary of the path of Buddhist practices leading to liberation from samsara, the painful cycle of rebirth, in the form of nirvana. The Eightfold Path consists of eight practices: ...

and the Buddha emphasizes the importance of the eight attainments or jhanas. * In

Mahayana ''Mahāyāna'' (; "Great Vehicle") is a term for a broad group of Buddhist traditions, texts, philosophies, and practices. Mahāyāna Buddhism developed in India (c. 1st century BCE onwards) and is considered one of the three main existing br ...

Buddhism, the branches of the Eightfold Path are embodied by the Eight Great Bodhisattvas: (

Manjusri Mañjuśrī (Sanskrit: मञ्जुश्री) is a ''bodhisattva'' associated with '' prajñā'' (wisdom) in Mahāyāna Buddhism. His name means "Gentle Glory" in Sanskrit. Mañjuśrī is also known by the fuller name of Mañjuśrīkumāra ...

Vajrapani (Sanskrit; Pali: Vajirapāṇi, meaning, " Vajra in ishand") is one of the earliest-appearing bodhisattvas in Mahayana Buddhism. He is the protector and guide of Gautama Buddha and rose to symbolize the Buddha's power. Vajrapāni is also ...

Avalokiteśvara In Buddhism, Avalokiteśvara (Sanskrit: अवलोकितेश्वर, IPA: ) is a bodhisattva who embodies the compassion of all Buddhas. He has 108 avatars, one notable avatar being Padmapāṇi (lotus bearer). He is variably depicted, ...

, Maitreya, Ksitigarbha, Nivaranavishkambhi, Akasagarbha, and Samantabhadra). These are later (controversially) associated with the Eight Consciousnesses according to the

Yogacara Yogachara ( sa, योगाचार, IAST: '; literally "yoga practice"; "one whose practice is yoga") is an influential tradition of Buddhist philosophy and psychology emphasizing the study of cognition, perception, and consciousness through ...

school of thought: consciousness in the five senses, thought-consciousness, self-consciousness, and unconsciousness-"consciousness" or "store-house consciousness" (alaya-vijñana). The "irreversible" state of enlightenment, at which point a Bodhisattva goes on "autopilot", is the Eight Ground or ''bhūmi''. In general, "eight" seems to be an auspicious number for Buddhists, e.g., the "eight auspicious symbols" (the jewel-encrusted parasol; the goldfish (always shown as a pair, e.g., the glyph of Pisces); the self-replenishing amphora; the white ''kamala'' lotus-flower; the white conch; the eternal (Celtic-style, infinitely looping) knot; the banner of imperial victory; the eight-spoked wheel that guides the ship of state, or that symbolizes the Buddha's teaching). Similarly,

Buddha's birthday Buddha's Birthday (also known as Buddha Jayanti, also known as his day of enlightenment – Buddha Purnima, Buddha Pournami) is a Buddhist festival that is celebrated in most of East Asia and South Asia commemorating the birth of the Prince ...

falls on the 8th day of the 4th month of the Chinese calendar.

Judaism

* The religious rite of brit milah (commonly known as

circumcision Circumcision is a procedure that removes the foreskin from the human penis. In the most common form of the operation, the foreskin is extended with forceps, then a circumcision device may be placed, after which the foreskin is excised. Top ...

) is held on a baby boy's eighth day of life. *

Hanukkah or English translation: 'Establishing' or 'Dedication' (of the Temple in Jerusalem) , nickname = , observedby = Jews , begins = 25 Kislev , ends = 2 Tevet or 3 Tevet , celebrations = Lighting candles each night. ...

is an eight-day Jewish holiday that starts on the 25th day of

Kislev Kislev or Chislev (Hebrew: כִּסְלֵו, Standard ''Kīslev'' Tiberian ''Kīslēw''), also 'Chisleu' in the King James (authorized English) Bible, is the third month of the civil year and the ninth month of the ecclesiastical year on the H ...

. *

Shemini Atzeret Shemini Atzeret (—"Eighth ay ofAssembly") is a Jewish holiday. It is celebrated on the 22nd day of the Hebrew month of Tishrei in the Land of Israel, and on the 22nd and 23rd outside the Land, usually coinciding with late September or earl ...

(

Hebrew Hebrew (; ; ) is a Northwest Semitic language of the Afroasiatic language family. Historically, it is one of the spoken languages of the Israelites and their longest-surviving descendants, the Jews and Samaritans. It was largely preserved ...

: "Eighth Day of Assembly") is a one-day Jewish holiday immediately following the seven-day holiday of Sukkot.

Christianity

* The spiritual Eighth Day, because the number 7 refers to the days of the week (which repeat themselves). * The number of Beatitudes. * 1 Peter 3:20 states that there were eight people on

Noah's Ark Noah's Ark ( he, תיבת נח; Biblical Hebrew: ''Tevat Noaḥ'')The word "ark" in modern English comes from Old English ''aerca'', meaning a chest or box. (See Cresswell 2010, p.22) The Hebrew word for the vessel, ''teva'', occurs twice in ...

. * The

Antichrist In Christian eschatology, the Antichrist refers to people prophesied by the Bible to oppose Jesus Christ and substitute themselves in Christ's place before the Second Coming. The term Antichrist (including one plural form)1 John ; . 2 John . ...

is the eighth king in the

Book of Revelation The Book of Revelation is the final book of the New Testament (and consequently the final book of the Christian Bible). Its title is derived from the first word of the Koine Greek text: , meaning "unveiling" or "revelation". The Book of ...

Islam

* In Islam, eight is the number of

angel In various theistic religious traditions an angel is a supernatural spiritual being who serves God. Abrahamic religions often depict angels as benevolent celestial intermediaries between God (or Heaven) and humanity. Other roles inclu ...

s carrying the

throne A throne is the seat of state of a potentate or dignitary, especially the seat occupied by a sovereign on state occasions; or the seat occupied by a pope or bishop on ceremonial occasions. "Throne" in an abstract sense can also refer to the mona ...

of Allah in heaven. * The number of gates of heaven

Taoism

* Ba Gua *

Ba Xian The Eight Immortals () are a group of legendary '' xian'' ("immortals") in Chinese mythology. Each immortal's power can be transferred to a vessel () that can bestow life or destroy evil. Together, these eight vessels are called the "Covert Eight ...

* Ba Duan Jin

Other

* In

Wicca Wicca () is a modern Pagan religion. Scholars of religion categorise it as both a new religious movement and as part of the occultist stream of Western esotericism. It was developed in England during the first half of the 20th century and w ...

, there are eight Sabbats, festivals, seasons, or spokes in the

Wheel of the Year The Wheel of the Year is an annual cycle of seasonal festivals, observed by many modern pagans, consisting of the year's chief solar events (solstices and equinoxes) and the midpoints between them. While names for each festival vary among dive ...

. * In

Ancient Egyptian mythology Egyptian mythology is the collection of myths from ancient Egypt, which describe the actions of the Egyptian gods as a means of understanding the world around them. The beliefs that these myths express are an important part of ancient Egyptia ...

, the Ogdoad represents the eight primordial deities of creation. * In

Scientology Scientology is a set of beliefs and practices invented by American author L. Ron Hubbard, and an associated movement. It has been variously defined as a cult, a Scientology as a business, business, or a new religious movement. The most recent ...

there are eight dynamics of existence. * There is also the Ogdoad in

Gnosticism Gnosticism (from grc, γνωστικός, gnōstikós, , 'having knowledge') is a collection of religious ideas and systems which coalesced in the late 1st century AD among Jewish and early Christian sects. These various groups emphasized pe ...

As a lucky number

* The number eight is considered to be a lucky number in Chinese and other Asian cultures. Eight (; accounting ;

pinyin Hanyu Pinyin (), often shortened to just pinyin, is the official romanization system for Standard Chinese, Standard Mandarin Chinese in China, and to some extent, in Singapore and Malaysia. It is often used to teach Mandarin, normally writte ...

''bā'') is considered a lucky number in Chinese culture because it sounds like the word meaning to generate wealth (;

Pinyin Hanyu Pinyin (), often shortened to just pinyin, is the official romanization system for Standard Chinese, Standard Mandarin Chinese in China, and to some extent, in Singapore and Malaysia. It is often used to teach Mandarin, normally writte ...

: ''fā''). Property with the number 8 may be valued greatly by Chinese. For example, a Hong Kong

number plate A vehicle registration plate, also known as a number plate (British English), license plate (American English), or licence plate (Canadian English), is a metal or plastic plate attached to a motor vehicle or trailer for official identificatio ...

with the number 8 was sold for $640,000. The opening ceremony of the Summer Olympics in Beijing started at 8 seconds and 8 minutes past 8 pm (local time) on 8 August 2008. * In Pythagorean numerology (a

pseudoscience Pseudoscience consists of statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method. Pseudoscience is often characterized by contradictory, exaggerated or unfalsifiable clai ...

) the number 8 represents victory, prosperity and overcoming. * is also considered a lucky number in Japan, but the reason is different from that in Chinese culture. Eight gives an idea of growing prosperous, because the letter () broadens gradually. * The Japanese thought of as a holy number in the ancient times. The reason is less well-understood, but it is thought that it is related to the fact they used eight to express large numbers vaguely such as (literally, eightfold and twentyfold), (literally, eight clouds), (literally, eight millions of Gods), etc. It is also guessed that the ancient Japanese gave importance to pairs, so some researchers guess twice as , which is also guessed to be a holy number in those times because it indicates the world (north, south, east, and west) might be considered a very holy number. * In numerology, 8 is the number of building, and in some theories, also the number of destruction.

In astrology

* In

astrology Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of celestial objects. Di ...

, Scorpio is the 8th

astrological sign In Western astrology, astrological signs are the twelve 30-degree sectors that make up Earth's 360-degree orbit around the Sun. The signs enumerate from the first day of spring, known as the First Point of Aries, which is the vernal equinox. ...

of the

Zodiac The zodiac is a belt-shaped region of the sky that extends approximately 8° north or south (as measured in celestial latitude) of the ecliptic, the apparent path of the Sun across the celestial sphere over the course of the year. The pat ...

. * In the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...

, 8 was the number of "unmoving" stars in the sky, and symbolized the perfection of incoming planetary energy.

In music and dance

* A note played for one-eighth the duration of a whole note is called an

eighth note 180px, Figure 1. An eighth note with stem extending up, an eighth note with stem extending down, and an eighth rest. 180px, Figure 2. Four eighth notes beamed together. An eighth note (American) or a quaver ( British) is a musical note pla ...

, or quaver. * An octave, the interval between two

musical note In music, a note is the representation of a musical sound. Notes can represent the pitch and duration of a sound in musical notation. A note can also represent a pitch class. Notes are the building blocks of much written music: discretizatio ...

s with the same letter name (where one has double the frequency of the other), is so called because there are eight notes between the two on a standard major or minor diatonic scale, including the notes themselves and without chromatic deviation. The ecclesiastical

modes Mode ( la, modus meaning "manner, tune, measure, due measure, rhythm, melody") may refer to: Arts and entertainment * '' MO''D''E (magazine)'', a defunct U.S. women's fashion magazine * ''Mode'' magazine, a fictional fashion magazine which is ...

are ascending diatonic musical scales of eight notes or tones comprising an octave. * There are eight notes in the

octatonic scale An octatonic scale is any eight- note musical scale. However, the term most often refers to the symmetric scale composed of alternating whole and half steps, as shown at right. In classical theory (in contrast to jazz theory), this symmetric ...

. * There are eight musicians in a double quartet or an

. Both terms may also refer to a musical composition for eight voices or instruments. * Caledonians is a square dance for eight, resembling the

quadrille The quadrille is a dance that was fashionable in late 18th- and 19th-century Europe and its colonies. The quadrille consists of a chain of four to six '' contredanses''. Latterly the quadrille was frequently danced to a medley of opera melodie ...

. *

Album An album is a collection of audio recordings issued on compact disc (CD), vinyl, audio tape, or another medium such as digital distribution. Albums of recorded sound were developed in the early 20th century as individual 78 rpm records co ...

s with the number eight in their title include ''8'' by the Swedish band

Arvingarna Arvingarna is a Swedish dansband formed in Gothenburg in 1989. The group consists of Casper Janebrink (vocals and bass guitar), Lars Larsson (guitars, vocals and keyboards), Kim Carlsson (vocals and guitars) and Tommy Carlsson (drums and vocals). ...

, '' 8'' by the American rock band

Incubus An incubus is a demon in male form in folklore that seeks to have sexual intercourse with sleeping women; the corresponding spirit in female form is called a succubus. In medieval Europe, union with an incubus was supposed by some to result in t ...

, ''

The Meaning of 8 ''The Meaning of 8'' is the seventh studio album by the experimental indie rock band Cloud Cult Cloud Cult is an experimental indie rock band from St. Cloud, Minnesota, United States, led by singer-songwriter Craig Minowa. The name originated ...

'' by Minnesota indie rock band

Cloud Cult Cloud Cult is an experimental indie rock band from St. Cloud, Minnesota, United States, led by singer-songwriter Craig Minowa. The name originated from the ancient prophecies of indigenous North Americans. History Cloud Cult developed in 1995 ...

and ''8ight'' by Anglo-American singer-songwriter

Beatie Wolfe Beatie Wolfe is an Anglo-American award-winning, multimedia artist and musician described as a "musical weirdo and visionary" known for seeing music differently and creating new formats for music and art in the digital era. These projects inclu ...

. * Dream Theater's eighth album ''

Octavarium ''Octavarium'' is the eighth studio album by American progressive metal band Dream Theater. Released on June 7, 2005, it was the band's final release with Atlantic Records. Recorded between September 2004 and February 2005, it was the last albu ...

'' contains many different references to the number 8, including the number of songs and various aspects of the music and cover artwork. * "Eight maids a-milking" is the gift on the eighth day of Christmas in the carol "

The Twelve Days of Christmas The Twelve Days of Christmas, also known as Twelvetide, is a festive Christian season celebrating the Nativity of Jesus. In some Western ecclesiastical traditions, "Christmas Day" is considered the "First Day of Christmas" and the Twelve Days a ...

". * The

8-track cartridge The 8-track tape (formally Stereo 8; commonly called eight-track cartridge, eight-track tape, and eight-track) is a magnetic tape sound recording technology that was popular from the mid-1960s to the early 1980s, when the compact cassette, wh ...

is a musical recording format. * "#8" is the stage name of Slipknot vocalist Corey Taylor. * "Too Many Eights" is a song by Athens, Georgia's Supercluster. *

Eight Seconds Eight Seconds was a Canadian synthpop/progressive rock band formed in 1982 in Ottawa. They are perhaps best known for their 1986 single "Kiss You (When It's Dangerous)" which peaked at #14 in 1987 and was on the charts for 28 weeks in Canada from ...

, a Canadian musical group popular in the 1980s with their most notable song "Kiss You (When It's Dangerous)". * "

Eight Days a Week "Eight Days a Week" is a song by the English rock band the Beatles. It was written by Paul McCartney and John Lennon based on McCartney's original idea. The song was released in the United Kingdom in December 1964 on the album ''Beatles for Sale ...

" is a #1 single for the music group

The Beatles The Beatles were an English rock band, formed in Liverpool in 1960, that comprised John Lennon, Paul McCartney, George Harrison and Ringo Starr. They are regarded as the most influential band of all time and were integral to the developmen ...

. * ''Figure 8'' is the fifth studio album by singer-songwriter Elliott Smith, released in the year 2000, an album released by Julia Darling in 1999, and an album released by

Outasight Richard Andrew (born February 17, 1983), better known by his stage name Outasight, is an American singer-songwriter, rapper, and record producer born and raised in Yonkers, New York. Though he is considered a pop artist, he is influenced by oth ...

in 2011. * Ming Hao from the k-pop group Seventeen goes by the name "The8". * "8 (circle)" is the eighth song on the album ''

22, A Million ''22, A Million'' is the third studio album by American indie folk band Bon Iver, released on September 30, 2016. Recorded in lead member Justin Vernon's April Base studio in Eau Claire, Wisconsin, the album marks a major shift in the band's sou ...

'' by the American band

Bon Iver Bon Iver ( ) is an American indie folk band founded in 2006 by singer-songwriter Justin Vernon. Vernon released Bon Iver's debut album, ''For Emma, Forever Ago,'' independently in July 2007. The majority of the album was recorded while Vernon ...

. * "8" is the eighth song on the album ''

When We All Fall Asleep, Where Do We Go? ''When We All Fall Asleep, Where Do We Go?'' (stylized in all caps) is the debut studio album by American singer and songwriter Billie Eilish. It was released on March 29, 2019, by Darkroom and Interscope Records in the US and Polydor Records ...

'' by

Billie Eilish Billie Eilish Pirate Baird O'Connell ( ; born December 18, 2001) is an American singer-songwriter. She first gained public attention in 2015 with her debut single " Ocean Eyes", written and produced by her brother Finneas O'Connell, with whom ...

In film and television

* ''

8 Guys ''8 Guys'' is a short film written and directed by American comedian Dane Cook. It was released in 2003, and was produced by Barry Katz and Brian Volk-Weiss. In addition to Cook, the film features Alonzo Bodden, Jay Davis, John DiResta, Rusty D ...

'' is a 2003 short film written and directed by

Dane Cook Dane Jeffrey Cook (born March 18, 1972) is an American stand-up comedian and film actor. He has released six comedy albums: '' Harmful If Swallowed''; ''Retaliation''; ''Vicious Circle''; '' Rough Around the Edges: Live from Madison Square Garde ...

. * ''

8 Man or or is a manga and superhero anime created in 1963 by science fiction writer Kazumasa Hirai and manga artist Jiro Kuwata. 8 Man is considered Japan's earliest cyborg superhero, pre-dating ''Kamen Rider.'' The manga was published ...

'' (or ''Eightman''): 1963 Japanese manga and anime superhero. * ''8 Mile'' is a 2002 film directed by

Curtis Hanson Curtis Lee Hanson (March 24, 1945 – September 20, 2016) was an American film director, screenwriter, and producer. His directing work included the psychological thriller '' The Hand That Rocks the Cradle'' (1992), the neo-noir crime film ''L. ...

. * ''8 mm'' is a 1999 film directed by

Joel Schumacher Joel T. Schumacher (; August 29, 1939June 22, 2020) was an American film director, producer and screenwriter. Raised in New York City by his mother, Schumacher graduated from Parsons School of Design and originally became a fashion designer. H ...

. * '' 8 Women'' (Original French title: ) is a 2001 film directed by

François Ozon François Ozon (; born 15 November 1967) is a French film director and screenwriter. Ozon is considered one of the most important modern French filmmakers. His films are characterized by aesthetic beauty, sharp satirical humor and a free-wheeli ...

. * ''

Eight Below ''Eight Below'' is a 2006 American survival drama film, a remake based on the 1983 Japanese film ''Antarctica'' by Toshirô Ishidô, Koreyoshi Kurahara, Tatsuo Nogami and Susumu Saji. It was produced by Patrick Crowley and David Hoberman, direc ...

'' is a 2006 film directed by Frank Marshall. * ''

Eight Legged Freaks ''Eight Legged Freaks'' (originally titled ''Arach Attack'', under which it was released in some parts of Europe and other countries around the world) is a 2002 monster comedy film directed by Ellory Elkayem and starring David Arquette, Kari Wu ...

'' is a 2002 film directed by

Ellory Elkayem Ellory Elkayem (born 12 August 1970) is a New Zealand film director. Born in Christchurch, Elkayem began making films at a young age. He later attended a film school designed to give students practical experience and preparation for a career in ...

. * ''

Eight Men Out ''Eight Men Out'' is a 1988 American sports drama film based on Eliot Asinof's 1963 book ''Eight Men Out: The Black Sox and the 1919 World Series''. It was written and directed by John Sayles. The film is a dramatization of Major League Baseball' ...

'' is a 1988 film directed by

John Sayles John Thomas Sayles (born September 28, 1950) is an American independent film director, screenwriter, editor, actor, and novelist. He has twice been nominated for the Academy Award for Best Original Screenplay, for ''Passion Fish'' (1992) and '' ...

. * ''

Jennifer Eight ''Jennifer 8'' is a 1992 American thriller film written and directed by Bruce Robinson and starring Andy García, Uma Thurman, and John Malkovich. Plot Former Los Angeles policeman John Berlin is teetering toward burnout after the collapse of hi ...

'', also known as ''Jennifer 8'', is a 1992 film written and directed by

Bruce Robinson Bruce Robinson (born 2 May 1946) is an English actor, director, screenwriter and novelist. He wrote and directed the cult classic ''Withnail and I'' (1987), a film with comic and tragic elements set in London in the late 1960s, which drew on hi ...

. * ''

Eight Is Enough ''Eight Is Enough'' is an American television comedy-drama series that ran on ABC from March 15, 1977, until May 23, 1981. The show was modeled on the life of syndicated newspaper columnist Tom Braden, a real-life parent with eight children, who ...

'' is an American television comedy-drama series. * In ''

Stargate SG-1 ''Stargate SG-1'' (often stylized in all caps, or abbreviated ''SG-1'') is a military science fiction adventure television series within Metro-Goldwyn-Mayer's ''Stargate'' franchise. The show, created by Brad Wright and Jonathan Glassner, ...

'' and ''

Stargate Atlantis ''Stargate Atlantis'' (usually stylized in all caps and often abbreviated ''SGA'') is an adventure and military science fiction television series and part of MGM's ''Stargate'' franchise. The show was created by Brad Wright and Robert C. Coop ...

'', dialing an 8-chevron address will open a

wormhole A wormhole ( Einstein-Rosen bridge) is a hypothetical structure connecting disparate points in spacetime, and is based on a special solution of the Einstein field equations. A wormhole can be visualized as a tunnel with two ends at separate p ...

to another galaxy. * ''

The Hateful Eight ''The Hateful Eight'' (sometimes marketed as ''The H8ful Eight'' or ''The Hateful 8'') is a 2015 American Western mystery thriller film written and directed by Quentin Tarantino. It stars Samuel L. Jackson, Kurt Russell, Jennifer Jason Leig ...

'' is a 2015 American western mystery film written and directed by

Quentin Tarantino Quentin Jerome Tarantino (; born March 27, 1963) is an American film director, writer, producer, and actor. His films are characterized by stylized violence, extended dialogue, profanity, dark humor, non-linear storylines, cameos, ensembl ...

. * ''

Kate Plus 8 ''Jon & Kate Plus 8'', later known as ''Kate Plus 8'', is an American reality television series starring Kate Gosselin, Jon Gosselin, and their eight children, which ran from April 4, 2007 to July 24, 2017. History After the success of two on ...

'' is an American reality television show.

In sports and other games

* Eight-ball

pool Pool may refer to: Water pool * Swimming pool, usually an artificial structure containing a large body of water intended for swimming * Reflecting pool, a shallow pool designed to reflect a structure and its surroundings * Tide pool, a rocky po ...

is played with a cue ball and 15 numbered balls, the black ball numbered 8 being the middle and most important one, as the winner is the player or side that legally pockets it after first pocketing its numerical group of 7 object balls (for other meanings see ''

Eight ball (disambiguation) Eight-ball is a pool game played with a solids-and-stripes ball set. Eight-ball, 8-ball, or variants may also refer to: Games * Blackball (pool), or 8-ball pool, a British game played with a yellows-and-reds ball set * 8 ball, the black ball mar ...

''). * In

chess Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to dist ...

, each side has eight pawns and the board is made of 64 squares arranged in an eight by eight lattice. The

eight queens puzzle The eight queens puzzle is the problem of placing eight chess queens on an 8×8 chessboard so that no two queens threaten each other; thus, a solution requires that no two queens share the same row, column, or diagonal. There are 92 solutions. ...

is a challenge to arrange eight queens on the board so that none can capture any of the others. * In the game of eights or

Crazy Eights Crazy Eights is a shedding-type card game for two to seven players and the best known American member of the Eights Group which also includes Pig and Spoons. The object of the game is to be the first player to discard all of their cards. The ga ...

, each successive player must play a card either of the same suit or of the same rank as that played by the preceding player, or may play an eight and call for any suit. The object is to get rid of all one's cards first. * In

association football Association football, more commonly known as football or soccer, is a team sport played between two teams of 11 players who primarily use their feet to propel the ball around a rectangular field called a pitch. The objective of the game is ...

, the number 8 has historically been the number of the Central Midfielder. * In Australian rules football, the top eight teams at the end of the Australian Football League regular season qualify for the

finals series Final, Finals or The Final may refer to: *Final (competition), the last or championship round of a sporting competition, match, game, or other contest which decides a winner for an event ** Another term for playoffs, describing a sequence of cont ...

(i.e. playoffs). * In

baseball Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play generally beginning when a player on the fielding t ...

: ** The center fielder is designated as number 8 for scorekeeping purposes. ** The

College World Series The College World Series (CWS), officially the NCAA Men's College World Series (MCWS), is an annual baseball tournament held in June in Omaha, Nebraska. The MCWS is the culmination of the National Collegiate Athletic Association (NCAA) Divisi ...

, the final phase of the NCAA Division I tournament, features eight teams. * In

rugby union Rugby union, commonly known simply as rugby, is a close-contact team sport that originated at Rugby School in the first half of the 19th century. One of the two codes of rugby football, it is based on running with the ball in hand. In it ...

, the only position without a proper name is the Number 8, a forward position. * In

rugby league Rugby league football, commonly known as just rugby league and sometimes football, footy, rugby or league, is a full-contact sport played by two teams of thirteen players on a rectangular field measuring 68 metres (75 yards) wide and 11 ...

: ** Most competitions (though not the Super League, which uses static squad numbering) use a position-based player numbering system in which one of the two starting props wears the number 8. ** The Australia-based

National Rugby League The National Rugby League (NRL) is an Australasian rugby league club competition which contains clubs from New South Wales, Queensland, Victoria, the Australian Capital Territory and New Zealand. The NRL formed in 1998 as a joint partnership ...

has its own 8-team finals series, similar but not identical in structure to that of the Australian Football League. * In

rowing Rowing is the act of propelling a human-powered watercraft using the sweeping motions of oars to displace water and generate reactional propulsion. Rowing is functionally similar to paddling, but rowing requires oars to be mechanically ...

, an "eight" refers to a sweep-oar racing boat with a crew of eight rowers plus a

coxswain The coxswain ( , or ) is the person in charge of a boat, particularly its navigation and steering. The etymology of the word gives a literal meaning of "boat servant" since it comes from ''cock'', referring to the cockboat, a type of ship's boa ...

. * In the 2008 Games of the XXIX Olympiad held in

Beijing } Beijing ( ; ; ), alternatively romanized as Peking ( ), is the capital of the People's Republic of China. It is the center of power and development of the country. Beijing is the world's most populous national capital city, with over 21 ...

, the official opening was on 08/08/08 at 8:08:08 p.m. CST. * In Rock Climbing, climbers frequently use the Figure Eight knot to tie into their harnesses.

In foods

Nestlé Nestlé S.A. (; ; ) is a Swiss multinational food and drink processing conglomerate corporation headquartered in Vevey, Vaud, Switzerland. It is the largest publicly held food company in the world, measured by revenue and other metrics, since ...

sells a brand of chocolates filled with peppermint-flavoured cream called

After Eight After Eight Mint Chocolate Thins, often referred to as simply "After Eights", are a brand of mint chocolate covered sugar confectionery. They were created by Rowntree Company Limited in the UK in 1962 and have been manufactured by Nestlé sin ...

, referring to the time 8 p.m. * There are eight vegetables in V8 juice.

In literature

* Eights may refer to octosyllabic, usually iambic,

lines Line most often refers to: * Line (geometry), object with zero thickness and curvature that stretches to infinity * Telephone line, a single-user circuit on a telephone communication system Line, lines, The Line, or LINE may also refer to: Arts ...

of verse. * The drott-kvaett, an Old Icelandic verse, consisted of a stanza of eight regular lines. * In

Terry Pratchett Sir Terence David John Pratchett (28 April 1948 – 12 March 2015) was an English humourist, satirist, and author of fantasy novels, especially comical works. He is best known for his '' Discworld'' series of 41 novels. Pratchett's first no ...

's ''

Discworld ''Discworld'' is a comic fantasy"Humorous Fantasy" in David Pringle, ed., ''The Ultimate Encyclopedia of Fantasy'' (pp.31-33). London, Carlton,2006. book series written by the English author Terry Pratchett, set on the Discworld, a flat ...

'' series, eight is a magical number and is considered taboo. Eight is not safe to be said by wizards on the

and is the number of Bel-Shamharoth. Also, there are eight days in a Disc week and eight colours in a Disc spectrum, the eighth one being

octarine The Discworld is the fictional setting for all of Terry Pratchett's ''Discworld'' fantasy novels. It consists of a large disc (complete with edge-of-the-world drop-off and consequent waterfall) resting on the backs of four huge elephants which ar ...

. *

Lewis Carroll Charles Lutwidge Dodgson (; 27 January 1832 – 14 January 1898), better known by his pen name Lewis Carroll, was an English author, poet and mathematician. His most notable works are '' Alice's Adventures in Wonderland'' (1865) and its sequ ...

's poem ''

The Hunting of the Snark ''The Hunting of the Snark'', subtitled ''An Agony in 8 Fits'', is a poem by the English writer Lewis Carroll. It is typically categorised as a nonsense poem. Written between 1874 and 1876, it borrows the setting, some creatures, and eight por ...

'' has 8 "fits" (cantos), which is noted in the full name "The Hunting of the Snark – ''An Agony, in Eight Fits''." * Eight apparitions appear to Macbeth in Act 4 scene 1 of Shakespeare's '' Macbeth'' as representations of the eight descendants of

Banquo Lord Banquo , the Thane of Lochaber, is a semi-historical character in William Shakespeare's 1606 play '' Macbeth''. In the play, he is at first an ally of Macbeth (both are generals in the King's army) and they meet the Three Witches togethe ...

In slang

* An "eighth" is a common measurement of marijuana, meaning an eighth of an

ounce The ounce () is any of several different units of mass, weight or volume and is derived almost unchanged from the , an Ancient Roman unit of measurement. The avoirdupois ounce (exactly ) is avoirdupois pound; this is the United States customa ...

. It is also a common unit of sale for

psilocybin mushrooms Psilocybin mushrooms, commonly known as magic mushrooms, are a polyphyletic informal group of fungi that contain psilocybin which turns into psilocin upon ingestion. Biological genera containing psilocybin mushrooms include ''Psilocybe'', ''Pa ...

. * Avril Lavigne's song "

Sk8er Boi "Sk8er Boi" (pronounced "skater boy") is a song by Canadian singer-songwriter Avril Lavigne, released as the second single from her debut album, '' Let Go'' (2002). It was written by Lavigne and the Matrix (Scott Spock, Lauren Christy, and Graham ...

" uses this convention in the title. * "Section 8" is common U.S. slang for "crazy", based on the U.S. military's Section 8 discharge for mentally unfit personnel. * The

Housing Choice Voucher Program Section 8 of the Housing Act of 1937 (), often called Section 8, as repeatedly amended, authorizes the payment of rental housing assistance to private landlords on behalf of low-income households in the United States. Fort Lauderdale, Florida Ho ...

, operated by the

United States Department of Housing and Urban Development The United States Department of Housing and Urban Development (HUD) is one of the executive departments of the U.S. federal government. It administers federal housing and urban development laws. It is headed by the Secretary of Housing and Ur ...

, is commonly referred to as the Section 8 program, as this was the original section of the Act which instituted the program. * In Colombia and

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

, "volverse un ocho" (meaning to tie oneself in a figure 8) refers to getting in trouble or contradicting oneself. * In China, "8" is used in chat speak as a term for parting. This is due to the closeness in pronunciation of "8" (bā) and the English word "bye".

References

External links

The Octonions
John C. Baez {{DEFAULTSORT:8 (Number) Integers 8 (number)

In mathematics

List of basic calculations

Etymology

Evolution of the Arabic digit

In science

Physics

Astronomy

Chemistry

Geology

Biology

Psychology

In technology

In measurement

In culture

Currency

Architecture

In religion, folk belief and divination

Hinduism

Buddhism

Judaism

Christianity

Islam

Taoism

Other

As a lucky number

In astrology

In music and dance

In film and television

In sports and other games

In foods

In literature

In slang

See also

References

External links