Tera-

From HandWiki

Tera is a unit prefix in the metric system denoting multiplication by one trillion, or 1012 or 1000000000000 (one trillion short scale; one billion long scale). It has the symbol T. Tera is derived from the Greek word τέρας teras, meaning "monster";[1] also it resembles tetra, meaning "four" but with the middle letter removed as it is the fourth power of 1000.[2] The unit prefix was confirmed for use in the International System of Units (SI) in 1960.

Examples of its use:

  • terahertz radiation: electromagnetic waves within the band of frequencies from 0.3 to 3 THz. Visible light is around 500 THz.
  • terabit and terabyte, units used in data storage. Tebi-, or 240 is the closest binary prefix being ≈9.95% greater than 1012.
  • teragram: equal to 109 kg. The Great Pyramid of Giza has a mass of about 6 Tg.
  • terasecond: approximately 31,558 years
  • teralitre: equal to 109 m3. Lake Zurich contains about 4 TL of water.
  • terawatt: used to measure total human energy consumption. In 2010 it was 16 TW (TJ/s).
  • terametre: (= 1,000,000,000 km): Light travels 1.079 Tm in one hour.
  • terajoule: equal to 1012 J of energy, approximately 1/4 kiloton of TNT.
Prefix Base 10 Decimal English word Adoption[nb 1]
Name Symbol Short scale Long scale
yotta Y  1024 1000000000000000000000000  septillion  quadrillion 1991
zetta Z  1021 1000000000000000000000  sextillion  trilliard 1991
exa E  1018 1000000000000000000  quintillion  trillion 1975
peta P  1015 1000000000000000  quadrillion  billiard 1975
tera T  1012 1000000000000  trillion  billion 1960
giga G  109 1000000000  billion  milliard 1960
mega M  106 1000000  million 1873
kilo k  103 1000  thousand 1795
hecto h  102 100  hundred 1795
deca da  101 10  ten 1795
 100 1  one
deci d  10−1 0.1  tenth 1795
centi c  10−2 0.01  hundredth 1795
milli m  10−3 0.001  thousandth 1795
micro μ  10−6 0.000001  millionth 1873
nano n  10−9 0.000000001  billionth  milliardth 1960
pico p  10−12 0.000000000001  trillionth  billionth 1960
femto f  10−15 0.000000000000001  quadrillionth  billiardth 1964
atto a  10−18 0.000000000000000001  quintillionth  trillionth 1964
zepto z  10−21 0.000000000000000000001  sextillionth  trilliardth 1991
yocto y  10−24  0.000000000000000000000001  septillionth  quadrillionth 1991
  1. Prefixes adopted before 1960 already existed before SI. 1873 was the introduction of the CGS system.

See also

References

  1. "SI prefixes and their etymologies". US Metric Association. https://usma.org/si-prefixes-and-their-etymologies. Retrieved 2021-06-11. 
  2. C. Upward, G. Davidson, The History of English Spelling, Wiley-Blackwell (2011)