{{redirect|Nine}} {| width="250" border="1" style="float: right; background: #feffff; border-collapse: collapse; margin: 0.5em" |- | colspan="2" | {{numbers (digits)}} |- | Cardinal | 9
nine |- | Ordinal | 9th
ninth |- | Numeral_system | Novenary |- | Factorization | $3^2$ |- | Divisors | 1, 3, 9 |- | prefixes | ennea- (from Greek) nona- (from Latin) |- | Binary | 1001 |- | Octal | 11 |- | Duodecimal | 9 |- | Hexadecimal | 9 |- | Arabic-Indic numeral | ٩ |- | Armenian numeral | Թ |- | Chinese numeral | 九
玖 (formal writing) |- | Eastern Arabic-Indic (Persian and Urdu) numeral | ۹ |- | Greek numeral | θ´ |- | Hebrew numeral | ט (Tet) |- | Indian (Hindi/Devanagari) numeral | ९ |- | Japanese numeral | 九
玖 (formal writing) |- | Roman numeral | IX |- | Unicode representation of Roman numeral | Ⅸ, ⅸ |- | Tamil numeral | ௯ |- | Thai numeral | ๙ |- |} '''9''' ('''nine''') is the Natural_number following 8 and preceding 10. ==In mathematics== Nine is a Composite_number, its proper Divisors being 1 and 3. It is 3 times 3 and hence the third Square_number. 9 is a Motzkin_number. In base 10 a number is evenly divisible by nine if and only if the iterative sum of its digits reduces to 9. A simple way of saying this is that if you multiply nine by any whole number, and repeatedly add the digits of the answer until it's just one digit, you will end up with nine: * 2*9=18 (1+8=9) * 3*9=27 (2+7=9) * 9*9=81 (8+1=9) * 234*9=2106 (2+1+0+6=9) * 578329*9=5204961 (5+2+0+4+9+6+1=27 (2+7=9)) The only other number with this property is three. In base N, the Divisors of N − 1 have this property. Another consequence of 9 being 10 − 1, is that it is also a Kaprekar_number. Since $9\; =\; 3^\{2^1\}$, 9 is an Exponential_factorial. In Probability, the '''nine''' is a Logarithmic_measure of probability of an event, defined as the negative of the base-10 Logarithm of the probability of the event's complement. For example, an event that is 99% likely to occur has an unlikelihood of 1% or 0.01, which amounts to −log₁₀ 0.01 = 2 nines of probability. Zero probability gives zero nines (−log₁₀ 1 = 0). The purity of chemicals (see Nine_(purity)), the effectivity of processes, the Availability of systems etc. can similarly be expressed in nines. For example, "five nines" (99.999%) availability implies a total Downtime of no more than five minutes per year. This measure can be confusing, a fact which is discussed in The_Myth_of_the_Nines. Six recurring nines appear in the decimal places 762 through 767 of Pi. This is known as the Feynman_point (see also MathWorld). A Polygon with nine sides is called an Enneagon (technically) or nonagon (in common usage). A group of nine of anything is called an ennead. ===In numeral systems=== {| border=1 cellpadding=0 cellspacing=1 |- ! Base !! Numeral_system |- | 2 || binary || 1001 |- | 3 || Ternary || 100 |- | 4 || quaternary || 21 |- | 5 || Quinary || 14 |- | 6 || Senary || 13 |- | 7 || Septenary || 12 |- | 8 || Octal || 11 |- | 9 || Novenary || 10 |- | colspan=2 | over 9 (Decimal, Hexadecimal) || 9 |} ==The Arabic glyph== Image:Evo9glyph.png In the beginning, various Indians wrote 9 in a way that pretty much looks like our modern closing question mark, but dotless. The Kshtrapa, Andhra and Gupta started curving the bottom vertical line coming up with a 3-look-alike. The Nagari continued the bottom stroke to make a circle to enclose the 3-look-alike, in much the same way that the @ character encircles a lowercase a. (The Nagari glyph might remind some of the Baskin_Robbins 31 flavors logo). As time went on, the enclosing circle became bigger and its line continued beyond the circle downwards, and the 3-look-alike became smaller. Soon, all that was left of the 3-look-alike was a squiggle. The Arabs simply connected that squiggle to the downward stroke at the middle, and all the Europeans did to the glyph was purely cosmetic. In fonts with Text_figures, 9 usually has a descender, for example, Image:TextFigs196.png. ==As lucky or unlucky number== Nine (九 Pinyin jiǔ) is considered a good number in Chinese_culture because it sounds the same as the word "longlasting" (久 Pinyin jiǔ). The Japanese consider 9 to be unlucky, however. According to Anton_Szandor_LaVey, as written on his book ''The_Satanic_Rituals'', 9 is the number of Satan. In Thai language, the word for nine, 'gao', is the same as the verb for 'to develop or progress'. Important Buddhist rituals usually involve nine monks. ==In science== *Nine is the Atomic_number of Fluorine '''In Astronomy''', : Messier_object M9, a magnitude 9.0 Globular_cluster in the constellation Ophiuchus. : The New_General_Catalogue object NGC_9, a Spiral_galaxy in the Constellation Pegasus :The Saros number of the Solar_eclipse series which began on -2568 February_6 and ended on -1252 April_4. The duration of Saros series 9 was 1316.2 years, and it contained 74 solar eclipses. :The Saros number of the Lunar_eclipse series which began on -2501 June_26 and ended on -1149 September_16. The duration of Saros series 9 was 1352.2 years, and it contained 76 lunar eclipses. :There are nine Planets in our Solar_system. ==In music== In Music_theory a Ninth is the ninth Note of a musical scale or the interval between the first note and the ninth. A ninth chord is a chord with a ninth. Ludwig_van_Beethoven, Franz_Schubert, Anton_Bruckner, and Ralph_Vaughan_Williams wrote nine symphonies. After Beethoven died leaving his Tenth Symphony unfinished, many composers were superstitious about writing Ninth Symphonies for the rest of the nineteenth century. Gustav_Mahler tried to "cheat death" by writing an orchestral song cycle entitled ''Das_Lied_von_der_Erde'' instead of an instrumental Ninth Symphony. Afterwards he wrote a work called Ninth Symphony, but thought of it as his Tenth. He died with his Tenth (or, strictly and in his mind, his Eleventh) unfinished. Perhaps Antonín Dvořák was also superstitious about the number nine, because he wrote no symphonies after his ''New World Symphony'', which is nowadays considered his Ninth, but which he thought of was his Eighth because he considered the score of his early C minor Symphony lost forever. He lived for seven more years. In the twentieth century, a handful of composers, such as Dmitri_Shostakovich, have written a Ninth Symphony and lived to write more. Nine is the number of Valkyries in Richard_Wagner's ''Die Walküre''. Bands with the number nine in their name include Stroke_9, Nine_Days and Nine_Inch_Nails. In Pop_music, the song "Love Potion #9" was written by Jerry_Leiber_and_Mike_Stoller (who also wrote "Riot_in_Cell_Block_No._9"), and became a hit for The Searchers in 1965. The_Beatles released a song called "Revolution_9" which appears on ''The_White_Album'' (more properly known as ''The Beatles)''; its principle vocal feature is a voice repeating, ''"Number nine...number nine...number nine..."'' John_Lennon, the primary composer of "Revolution 9", also released a solo recording entitled "#9 Dream", leading his biographer to speculate that he had an obsession with the number. Composer Maury_Yeston adapted Fellini's 8 1/2 for Broadway as the musical Nine, which won several Tony_Awards in 1982, and was successfully revived in 2003 starring Antonio_Banderas. ''9'' is a full-length album by the heavy metal band Mercyful_Fate, released in 1999. Fairport_Convention also released an album with the number for a title. ==In sports== *A batting lineup in Baseball consists of nine players. *In Chess, the maximum number of queens one side could possibly have after queening all pawns. *Nine_ball is the standard professional Billiards variant played in the United States * In Rugby_union the scrum-half wears the 9 shirt. * In Baseball, nine represents the Right_fielder's position. * The retired uniform numbers of former baseball player Ted_Williams and former hockey player Gordie_Howe ==In technology== * ISO_9 is the ISO's standard for the transliteration of Cyrillic characters into Latin characters * In the Rich_Text_Format specification, 9 is the language code for the English_language. All codes for regional variants of English are congruent to 9 mod 256. *On most phones, the 9 key is associated with the letters W, X, and Y (and sometimes also Z), but on the BlackBerry it is the key for M. *In Mac_OS_X, the F9 Function_key tiles all open windows and sizes them to fit together. * The number of minutes some Alarm_clocks give you after you press the Snooze_button. ==In other fields== *Nine is the highest single-digit number in the decimal system. *In the NATO_phonetic_alphabet, the digit 9 is called "Niner". *Nine is the number of musicians in a Nonet. *Nine babies born into a single birth are called Nonuplets, although not one baby born into a set of nonuplets has ever survived infancy. *A Novena lasts for nine days. *Nine judges sit on the United_States_Supreme_Court. *There are nine members of The_Fellowship_of_the_Ring in The_Lord_of_the_Rings saga, to balance and combat the nine Nazgûl, or Ringwraiths. *The ordinal adjective is ''nonary''. *In Greek mythology there are nine Muses. *In Egyptian mythology, there are nine major gods and goddesses (see also Ennead). *There are nine basic personality types represented on the Enneagram. *In Astrology, Sagittarius is the 9th Astrological_sign of the Zodiac. *Joel_Garreau identified nine different "nations" of North America. *Nine months is the Gestation period for Humans. *A standard work day of 9 to 5 begins at 9 a.m. *Stanines are measured on a scale of 1 to 9. *The name of the area called ''Kowloon'' in Hong_Kong literally means: ''nine dragons''. *Someone dressed "to the nines" is dressed up as much as they can be. *Nine_Lives Cat Food got its name from the legend that a Cat has nine lives. *Nine_rank_system *''The_Nine_Chapters_on_the_Mathematical_Art'' *Nine_Worthies * 9:_The_Last_Resort was a 1995 computer game. * Historical years: '''9 A.D.''', 9 B.C., or 1909 09 Da:9_(tal) De:Neun Es:Nueve Eo:Naŭ Fi:9_(luku) Fr:9_(nombre) Ko:9 It:Nove He:9_(מספר) La:9 Nah:Chicunahui Nl:Negen Ja:9 No:9_(tall) Nn:Talet_9 Ru:9_(число) Sl:9_(število) Sv:9_(tal) Th:9_(จำนวน) Zh:9