8 Explained

Number:8
Numeral:octal
Divisor:1, 2, 4, 8
Roman:VIII, viii
Greek Prefix:octa-/oct-
Latin Prefix:octo-/oct-
Lang1:Greek
Lang1 Symbol:η (or Η)
Lang2:Arabic, Kurdish, Persian, Sindhi, Urdu
Lang3:Amharic
Lang3 Symbol:
Lang4:Bengali
Lang5:Chinese numeral
Lang5 Symbol:八,捌
Lang6:Devanāgarī
Lang7:Kannada
Lang8:Malayalam
Lang9:Telugu
Lang10:Tamil
Lang11:Hebrew
Lang12:Khmer
Lang12 Symbol:
Lang14:Thai
Lang14 Symbol:
Lang15:Armenian
Lang15 Symbol:Ը ը
Lang16:Babylonian numeral
Lang17:Egyptian hieroglyph
Lang19:Morse code
Cardinal:eight

8 (eight) is the natural number following 7 and preceding 9.

Etymology

English eight, from Old English , æhta, Proto-Germanic *ahto is a direct continuation of Proto-Indo-European

-, and as such cognate with Greek Greek, Ancient (to 1453);: ὀκτώ and Latin, 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.The adjective octuple (Latin) may also be used as a noun, meaning "a set of eight items"; the diminutive octuplet 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, written Chinese: (Mandarin: ; Cantonese: baat), is from Old Chinese *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 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 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");[1] this same principle is found in Finnic

, which conveys a meaning of "two before (ten)". The Proto-Indo-European reconstruction - 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).[2]

Evolution of the Arabic digit

The modern digit 8, like all modern Arabic numerals other than zero, originates with the Brahmi numerals.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 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"). 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.[3]

Just as in most modern typefaces, in typefaces with text figures the character for the digit 8 usually has an ascender, as, for example, in .

The infinity symbol ∞, 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 for "one thousand" CIƆ, or alternatively from the final Greek letter, ω.

In mathematics

8 is a composite number and the first number which is neither prime nor semiprime. By Mihăilescu's Theorem, it is the only nonzero perfect power that is one less than another perfect power. 8 is the first proper Leyland number of the form, where in its case and both equal 2. 8 is a Fibonacci number and the only nontrivial Fibonacci number that is a perfect cube.[4] Sphenic numbers always have exactly eight divisors.[5] 8 is the base of the octal number system.[6]

Geometry

A polygon with eight sides is an octagon.[7] A regular octagon can fill a plane-vertex with a regular triangle and a regular icositetragon, as well as tessellate two-dimensional space alongside squares in the truncated square tiling. This tiling is one of eight Archimedean tilings that are semi-regular, or made of more than one type of regular polygon, and the only tiling that can admit a regular octagon.[8] The Ammann–Beenker tiling is a nonperiodic tesselation of prototiles that feature prominent octagonal silver eightfold symmetry, that is the two-dimensional orthographic projection of the four-dimensional 8-8 duoprism.[9]

An octahedron is a regular polyhedron with eight equilateral triangles as faces. is the dual polyhedron to the cube and one of eight convex deltahedra.[10] The stella octangula, or eight-pointed star, is the only stellation with octahedral symmetry. It has eight triangular faces alongside eight vertices that forms a cubic faceting, composed of two self-dual tetrahedra that makes it the simplest of five regular compounds. The cuboctahedron, 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, whose first stellation is the cube-octahedron compound.[11] [12]

Vector spaces

The octonions are a hypercomplex normed division algebra that are an extension of the complex numbers. They are a double cover of special orthogonal group SO(8). The special unitary group SO(3) has an eight-dimensional adjoint representation whose colors are ascribed gauge symmetries that represent the vectors of the eight gluons in the Standard Model. Clifford algebras display a periodicity of 8.[13]

Group theory

The lie group E8 is one of 5 exceptional lie groups.[14] [15] The order of the smallest non-abelian group whose subgroups are all normal is 8.

List of basic calculations

Division123456789101112131415
8 ÷ x842.21.61.1.10.0.80.0.0.0.0.5
x ÷ 80.1250.250.3750.50.6250.750.87511.1251.251.3751.51.6251.751.875
Exponentiation12345678910111213
88645124096327682621442097152167772161342177281073741824858993459268719476736549755813888
x1256656165536390625167961657648011677721643046721100000000214358881429981696815730721

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

Other uses

See also

External links

Notes and References

  1. Etymological Dictionary of Turkic Languages: Common Turkic and Interturkic stems starting with letters «L», «M», «N», «P», «S», Vostochnaja Literatura RAS, 2003, 241f. (altaica.ru)
  2. the hypothesis is discussed critically (and rejected as "without sufficient support") byWerner Winter, 'Some thought about Indo-European numerals' in: Jadranka Gvozdanović (ed.),Indo-European Numerals, Walter de Gruyter, 1992, 14f.
  3. 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): 395, Fig. 24.68.
  4. Bryan Bunch, The Kingdom of Infinite Number. New York: W. H. Freeman & Company (2000): 88
  5. Web site: Weisstein . Eric W. . Sphenic Number . 2020-08-07 . mathworld.wolfram.com . en . ...then every sphenic number n=pqr has precisely eight positive divisors.
  6. Web site: Weisstein . Eric W. . Octal . 2020-08-07 . mathworld.wolfram.com . en.
  7. Web site: Weisstein . Eric W. . Octagon . 2020-08-07 . mathworld.wolfram.com . en.
  8. Web site: Weisstein. Eric W.. Regular Octagon . 2022-06-25. mathworld.wolfram.com. en.
  9. Book: Katz, A . Matching rules and quasiperiodicity: the octagonal tilings . Beyond quasicrystals . Springer . 1995 . 141–189 . 978-3-540-59251-8 . 10.1007/978-3-662-03130-8_6 . F. . Axel . D. . Gratias.
  10. Web site: The Convex Deltahedra And the Allowance of Coplanar Faces . Roger Kaufman . The Kaufman Website . 2022-06-25.
  11. Web site: Weisstein . Eric W. . Cuboctahedron . 2022-06-25 . mathworld.wolfram.com . en .
  12. Book: Coxeter, H.S.M. . Harold Scott MacDonald Coxeter . 1973 . 1948 . Regular Polytopes . Dover . New York . 3rd . 18–19 . Regular Polytopes (book) .
  13. Book: Lounesto, Pertti. Clifford Algebras and Spinors. 2001-05-03. Cambridge University Press . 978-0-521-00551-7. 216. en. ...Clifford algebras, contains or continues with two kinds of periodicities of 8....
  14. Wilson . Robert A. . Robert Arnott Wilson . Octonions and the Leech lattice . 2542837 . 2009 . Journal of Algebra . 322 . 6 . 2186–2190. 10.1016/j.jalgebra.2009.03.021 . free .
  15. Book: Conway . John H. . John Horton Conway . Sloane . N. J. A. . Neil Sloane . https://link.springer.com/chapter/10.1007/978-1-4757-2016-7_8 . Sphere Packings, Lattices and Groups . Algebraic Constructions for Lattices . Springer . New York, NY . 1988 . 978-1-4757-2016-7 . 2196-9701 . 10.1007/978-1-4757-2016-7 .
  16. Book: Ilangovan, K.. Nuclear Physics. 2019-06-10. MJP Publisher. 30. en.
  17. Gell-Mann. M.. 1961-03-15. THE EIGHTFOLD WAY: A THEORY OF STRONG INTERACTION SYMMETRY. 4008239. en.
  18. Baxter . R. J. . 1971-04-05 . Eight-Vertex Model in Lattice Statistics . Physical Review Letters . 26 . 14 . 832–833 . 10.1103/PhysRevLett.26.832 . 1971PhRvL..26..832B.
  19. Web site: Messier Object 8. 2020-08-07. www.messier.seds.org.
  20. Book: Thomas, Mary Ann . Oxygen . 2004-08-15 . The Rosen Publishing Group, Inc . 978-1-4042-0159-0 . 12 . en . Knowing that oxygen has an atomic number of 8,.
  21. Book: Choppin . Gregory R. . Introductory chemistry . Johnsen . Russell H. . 1972 . Addison-Wesley Pub. Co. . 366 . 978-0-201-01022-0 . en . under normal conditions the most stable allotropic form (Fig. 23-8a). Sulfur molecules within the crystal consist of puckered rings of eight sulfur atoms linked by single....
  22. Book: Puri. Basant. Phytochemical Dictionary: A Handbook of Bioactive Compounds from Plants, Second Edition. Hall. Anne. 1998-12-16. CRC Press. 978-0-203-48375-6. 810. en. The chemical structure of lycopene consists of a long chain of eight isoprene units joined head to tail.
  23. Book: Parker, Barbara Keevil. Ticks. 2006-12-28. Lerner Publications . 978-0-8225-6464-5 . 7. en. Arachnids have eight legs.
  24. Book: Jackman, J. A.. A Field Guide to Spiders & Scorpions of Texas. 1997. Gulf Publishing Company. 978-0-87719-264-0. 70. en. Araneids have eight eyes.
  25. Book: Fisher. James. The Doubleday Pictorial Library of Nature: Earth, Plants, Animals . Huxley . Julian . 1961 . Doubleday . 311 . en . Polyps with eight branched tentacles and eight septa.
  26. Anthozoa . 02 . Bourne . Gilbert Charles . Gilbert Charles Bourne . 97–105; see page 100 . Zoantharia.....It is not known whether all the eight mesenteries of Edwardsia are developed simultaneously or not, but in the youngest form which has been studied all the eight mesenteries were present.
  27. Book: The Century Dictionary and Cyclopedia: A work of Universal Reference in all Departments of Knowledge with a New Atlas of the World . 1906 . 1384 . en . ...are radially symmetrical, and swim by means of eight meridional ciliated bands, ....
  28. Book: Parrish, Fred K.. Keys to Water Quality Indicative Organisms of the Southeastern United States. 1975. Environmental Protection Agency, Office of Research and Development, Environmental Monitoring and Support Laboratory, Biological Methods Branch, Aquatics Biology Section . 11 . en . ... the ascospores, are borne in sac like structures termed asci. The ascus usually contains eight as cospores,....
  29. Book: Dofka, Charline M.. Competency Skills for the Dental Assistant . 1996 . Cengage Learning. 978-0-8273-6685-5. 83. en. ...In each quadrant of the permanent set of teeth (dentition), there are eight teeth.
  30. Book: Quain, Jones. Quain's Elements of Anatomy. 1909. Longmans, Green, & Company. 52. en. These eight pairs are usually reckoned as eight cervical nerves ....
  31. Book: Beebe, John . Energies and Patterns in Psychological Type: The reservoir of consciousness . 2016-06-17 . Routledge . 978-1-317-41366-0 . 124 . en . Linda Berens used the term 'cognitive processes' (1999) to refer to the eight types of consciousness that Jung discovered..
  32. Web site: Definition of byte Dictionary.com. 2020-08-08. www.dictionary.com. en.
  33. Book: Kindem. Gorham. Introduction to Media Production: The Path to Digital Media Production. PhD. Robert B. Musburger. 2012-08-21. CRC Press . 978-1-136-05322-1. 320. en. There used to be two 8 mm formats: standard 8 mm and Super-8 mm..
  34. Book: The Library of Congress Veterans History Project: Field Kit : Conducting and Preserving Interviews. 2008. Veterans History Project, American Folklife Center, Library of Congress. 15. en. Betacam SX 8 mm Hi8, Digital8, Video8 DVD-Video";.
  35. Web site: Definition of eight Dictionary.com . 2020-08-08. www.dictionary.com. en.
  36. Book: Griffiths, Garth . Boating in Canada: Practical Piloting and Seamanship. 1971. University of Toronto Press. 978-0-8020-1817-5. 32. en. First is a stopper knot, the figure of eight, ....
  37. Book: The Milwaukee Cook Book . 1907 . Press of Houtkamp Printing. en.
  38. Web site: Definition of furlong Dictionary.com. 2020-08-08. www.dictionary.com. en.
  39. Web site: Definition of clove Dictionary.com . 2020-08-08 . www.dictionary.com . en.
  40. Book: Fairhall. David. Pass Your Yachtmaster. Peyton. Mike. 2013-05-17. A&C Black. 978-1-4081-5627-8. en. Gale warnings will be given if mean wind speeds of force 8 (34–40 knots).
  41. Eastern Prospects: Kiosks, Belvederes, Gazebos . 10.1023/A:1022691123957 . 2003 . Sayers . William . Neophilologus . 87 . 2 . 299–305 . 159542713 .
  42. Book: Halstead, Frank . 1927 . The Orders of Architecture . New York . John Wiley & Sons, Inc..
  43. Web site: Who are the eight vasus? . 2023-12-19 . Hinduism Stack Exchange . en.
  44. Book: Hatcher, Brian A. . Hinduism in the Modern World . 2015-10-05. Routledge. 978-1-135-04630-9. en. a group manifestation of eight forms.
  45. Book: Jeyaraj, Daniel. Genealogy of the South Indian Deities: An English Translation of Bartholomäus Ziegenbalg's Original German Manuscript with a Textual Analysis and Glossary . 2004-09-23 . Routledge . 978-1-134-28703-1 . 168 . en . He is one of the eight guardians of the world.
  46. Book: Ramachandran, Nirmala. Hindu Heritage. 2000. Stamford Lake Publication . 978-955-8733-09-7 . 72. en. The temple has eight monasteries, founded by Madhvacharya.
  47. Book: Issitt. Micah. Hidden Religion: The Greatest Mysteries and Symbols of the World's Religious Beliefs: The Greatest Mysteries and Symbols of the World's Religious Beliefs. Main. Carlyn. 2014-09-16. ABC-CLIO. 978-1-61069-478-0. 186. en. The dharmachakra is typically depicted with eight spokes,.
  48. Book: Hay, Jeff. World Religions. 2009-03-06. Greenhaven Publishing LLC. 978-0-7377-4627-3. 61. en. The focus of ordinary believers' religious life is on following a relevant version of the Eightfold Path ....
  49. Book: Rosten, Leo . The New Joys of Yiddish: Completely Updated . 2010-04-14 . Potter/Ten Speed/Harmony/Rodale . 978-0-307-56604-1 . 48 . en . Brit Milah is observed on a boy's eighth day of life.
  50. Book: Ross, Kathy . Crafts for Hanukkah . 2012-08-01 . Millbrook Press . 978-0-7613-6836-6 . 7. en . Hanukkah is an eight-day Jewish holiday.
  51. Book: Axelrod, Cantor Matt. Your Guide to the Jewish Holidays: From Shofar to Seder. 2013-12-24. Rowman & Littlefield . 978-0-7657-0990-5. 58. en. Shemini Atzeret—literally, "the eighth day of assembly".
  52. Web site: CATHOLIC ENCYCLOPEDIA: The Eight Beatitudes. 2020-08-09. www.newadvent.org.
  53. Book: Akintola, Olufolahan Olatoye. Nations of the World…How They Evolved!: Families and Nations That Came Out of Ham. 2011. Hilldew View International Limited . 978-0-9569702-2-0 . 8 . en . These eight souls in Noah's ark were the survivors....
  54. Book: Livingstone . Life Application New Testament Commentary . 2001 . Tyndale House Publishers, Inc. . 978-0-8423-7066-0 . en.
  55. Book: Mahmutćehajić, Rusmir . Maintaining the Sacred Center: The Bosnian City of Stolac . 2011 . World Wisdom, Inc . 978-1-935493-91-4 . 201 . en . ... at the last, eight Angels will carry the Throne....
  56. Web site: Names of the Gates of Heaven . 2023-12-19 . islamweb.net.
  57. Book: Little. Stephen. Taoism and the Arts of China. Eichman. Shawn. Shipper. Kristofer. Ebrey. Patricia Buckley. 2000-01-01. University of California Press. 978-0-520-22785-9. 139. en. Evidence for the early use of the Eight Trigrams in a religious Taoist....
  58. Book: Ho. Peter Kwok Man. The Eight Immortals of Taoism: Legends and Fables of Popular Taoism. Kwok. Man-Ho . O'Brien . Joanne . 1990 . Meridian . 978-0-452-01070-3. 7. en. ...famous Eight Immortals of China....
  59. Book: Zimmermann . Denise . The Complete Idiot's Guide to Wicca and Witchcraft . Gleason . Katherine . Liguana . Miria . 2006 . Penguin . 978-1-59257-533-6 . 172 . en . There are eight Sabbats.
  60. Book: Remler, Pat. Egyptian Mythology, A to Z. 2010. Infobase Publishing. 978-1-4381-3180-1. 79. en. ...of the gods of the Ogdoad, or the eight deities of the Egyptian creation....
  61. Book: Wallis, Roy . Roy Wallis . The Road to Total Freedom: A Sociological Analysis of Scientology . The Road to Total Freedom . 1977 . . 0231042000 . 4596322M.
  62. Book: David, Fideler . Jesus Christ, Sun of God: Ancient Cosmology and Early Christian Symbolism . 1993 . Quest Books . 978-0-8356-0696-7 . 128.
  63. Ang . Swee Hoon . Chinese consumers' perception of alpha-numeric brand names . Journal of Consumer Marketing . 1997 . 14 . 3 . 220–233 . 10.1108/07363769710166800 . https://web.archive.org/web/20111205013132/http://www.emeraldinsight.com/journals.htm?articleid=856257&show=abstract . 5 December 2011 . live . dmy-all .
  64. Hedonic Prices and House Numbers: The Influence of Feng Shui . International Real Estate Review . 1999 . 2 . 79–93 . Steven C. Bourassa . Vincent S. Peng . 1 . dead . https://www.webcitation.org/6XlGD7PlK?url=http://www.umac.edu.mo/fba/irer/papers/past/vol2_pdf/079-093LN-NZ.pdf . 13 April 2015 . dmy-all . 11 May 2011 .
  65. Web site: 2008-08-08. Olympics opening ceremony: China makes its point with greatestshow. 2022-11-29. the Guardian. en.
  66. Book: Jefkins, Frank. Modern Marketing Communications. 2012-12-06. Springer Science & Business Media. 978-94-011-6868-7. 36. en. ...eight being a lucky number in Japanese..
  67. Web site: Definition of SCORPIO. 2020-08-10. www.merriam-webster.com. en.
  68. Web site: Definition of eighth note Dictionary.com. 2020-08-09 . www.dictionary.com . en.
  69. Web site: Definition of OCTAVE. 2020-08-09. www.merriam-webster.com. en. a tone or note that is eight steps above or below another note or tone.
  70. Web site: Definition of octet Dictionary.com. 2020-08-09. www.dictionary.com. en. a company of eight singers or musicians..
  71. Web site: Definition of octet Dictionary.com. 2020-08-09 . www.dictionary.com. en. a musical composition for eight voices or instruments..
  72. Web site: 2017-03-17. Incubus Premiere New Song "Glitterbomb", Detail New Album "8". 2020-08-09. Theprp.com. en-US.
  73. Book: Tribble, Mimi. 300 Ways to Make the Best Christmas Ever!: Decorations, Carols, Crafts & Recipes for Every Kind of Christmas Tradition. 2004. Sterling Publishing Company, Inc.. 978-1-4027-1685-0. en.
  74. Web site: Eight Seconds Biography & History. 2020-08-10. AllMusic. en-us.
  75. Web site: The8 Credits. 2020-08-10 . AllMusic. en-us.
  76. Web site: Definition of EIGHT. 2020-08-10. www.merriam-webster.com. en.
  77. Web site: Buy After Eight® Online Nestlé Family ME. 2020-08-10. www.nestle-family.com.
  78. Web site: V8® Vegetable Juice Ingredients . 2023-12-19 . V8® Fruit and Vegetable Juices . en-US.
  79. Web site: Definition of DROTT-KVAETT. 2020-08-10. www.merriam-webster.com . en.
  80. Book: Collins . Robert . Science Fiction & Fantasy Book Review Annual . Latham . Robert . 1988 . Meckler . 289 . 978-0-88736-249-1 . en.
  81. Web site: The Hunting of the Snark. 2020-08-10. www.gutenberg.org.
  82. Web site: Franciosi . Anthony . 2019-10-25 . Weed Measurements: The Marijuana Metric System . 2023-12-19 . Honest Marijuana . en-US.
  83. Web site: CT Housing Choice Voucher Program . 2020-08-11 . www.cthcvp.org . Welcome to the Housing Choice Voucher Program (also known as Section 8).
  84. Book: Boys' Life . 1931 . Boy Scouts of America, Inc. . 20 . en . lunge forward upon this skate in a left outside forward circle, in just the reverse of your right outside forward circle, until you complete a figure 8..
  85. Book: Day, Cyrus Lawrence . The Art of Knotting & Splicing . 1986 . Naval Institute Press. 978-0-87021-062-4. 231. en. To make a line temporarily fast by winding it, figure – eight fashion, round a cleat, a belaying pin, or a pair of bitts..