Zetta-

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Zetta is a unit prefix in the metric system denoting a factor of 1021 or 1000000000000000000000. The prefix was added to the International System of Units (SI) in 1991 and has the symbol Z.

Zetta is evocative of the Latin numeral septem, meaning seven. Therefore it was used to denote the seventh power of 1000.[1]

A prefix of the same value, hepta, was informally introduced a few years before the promulgation of zetta. It was formed from the Greek ἑπτά, (hepta), also meaning seven. Hepta never received official sanction and is obsolete. Zeta (Ζήτα), although being the 6th letter of the Greek alphabet, denotes a value of seven (7) when used as a numeral.

Examples:

Prefix 1000m 10n Decimal English word Since[n 1]
name symbol short scale long scale
yotta Y  10008  1024 1000000000000000000000000  septillion  quadrillion 1991
zetta Z  10007  1021 1000000000000000000000  sextillion  thousand trillion 1991
exa E  10006  1018 1000000000000000000  quintillion  trillion 1975
peta P  10005  1015 1000000000000000  quadrillion  thousand billion 1975
tera T  10004  1012 1000000000000  trillion  billion 1960
giga G  10003  109 1000000000  billion  thousand million 1960
mega M  10002  106 1000000             million 1960
kilo k  10001  103 1000             thousand 1795
hecto h  10002/3  102 100             hundred 1795
deca da  10001/3  101 10             ten 1795
 10000  100 1             one
deci d  1000−1/3  10−1 0.1             tenth 1795
centi c  1000−2/3   10−2 0.01             hundredth 1795
milli m  1000−1  10−3 0.001             thousandth 1795
micro μ  1000−2  10−6 0.000001             millionth 1960
nano n  1000−3  10−9 0.000000001  billionth  thousand millionth 1960
pico p  1000−4  10−12 0.000000000001  trillionth  billionth 1960
femto f  1000−5  10−15 0.000000000000001  quadrillionth  thousand billionth 1964
atto a  1000−6  10−18 0.000000000000000001  quintillionth  trillionth 1964
zepto z  1000−7  10−21 0.000000000000000000001  sextillionth  thousand trillionth 1991
yocto y  1000−8  10−24  0.000000000000000000000001  septillionth  quadrillionth  1991
  1. ^ The metric system was introduced in 1795 with six prefixes. The other dates relate to recognition by a resolution of the CGPM.

Footnotes[edit]

  1. ^ "Resolution 4 of the 19th CGPM (Conférence Générale des Poids et Mesures)". BIPM (Bureau International des Poids et Mesures). Retrieved 2009-05-16. Les noms zepto et zetta évoquent le chiffre sept (septième puissance de 103) et la lettre « z » remplace la lettre « s » pour éviter le double emploi de la lettre « s » comme symbole. The names zepto and zetta are evocative of the numeral sept (seventh power of 103) and the letter 'z' is substituted for the letter 's' to avoid the duplicate use of the letter 's' as a symbol. 
  2. ^ http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html
  3. ^ http://hypertextbook.com/facts/2001/SyedQadri.shtml
  4. ^ http://physics.nist.gov/cgi-bin/cuu/Value?na
  5. ^ Compare zebibyte which is a multiple of 1024 as typical unit for information storage.

External links[edit]