Exa
Encyclopedia
Exa- is a prefix
in the metric system
denoting 1018 or .
Adopted in 1975, it comes from the Greek
ἕξ, used as a prefix ἑξά-, meaning six (like hexa-), because it is equal to 10006.
Examples:
SI prefix
The International System of Units specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol...
in the metric system
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
denoting 1018 or .
Adopted in 1975, it comes from the Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
ἕξ, used as a prefix ἑξά-, meaning six (like hexa-), because it is equal to 10006.
Examples:
- 1 EeV = 1018 electronvoltElectronvoltIn physics, the electron volt is a unit of energy equal to approximately joule . By definition, it is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt...
s = 0.1602 jouleJouleThe joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second... - 1 exasecond is approximately 32 billion years
- 1 exametre is approximately 110 light yearsLight YearsLight Years is the seventh studio album by Australian recording artist Kylie Minogue. It was released on 25 September 2000 by Parlophone and Mushroom Records. The album's style was indicative of her return to "mainstream pop dance tunes"....
- 0.43 Es ≈ the approximate age of the Universe
- 1.6 Em — 172 ± 12.5 light years — Diameter of Omega CentauriOmega CentauriOmega Centauri or NGC 5139 is a globular clusterin the constellation of Centaurus, discovered by Edmond Halley in 1677 who listed it as a nebula. Omega Centauri had been listed in Ptolemy's catalog 2000 years ago as a star. Lacaille included it in his catalog as number I.5...
(one of the largest known globular clusterGlobular clusterA globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
s, perhaps containing over a million starStarA star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s)
See also
- 1 exametre
- Binary prefixBinary prefixIn computing, a binary prefix is a specifier or mnemonic that is prepended to the units of digital information, the bit and the byte, to indicate multiplication by a power of 2...
- ExabyteExabyteThe exabyte is a unit of information or computer storage equal to one quintillion bytes . The unit symbol for the exabyte is EB...
- Exasecond
- Orders of magnitude (numbers)Orders of magnitude (numbers)This list contains selected positive numbers in increasing order, including counts of things, dimensionless quantity and probabilities. Each number is given a name in the short scale, which is used in English speaking countries, as well as a name in the long scale, which is used in some of the...
- SI prefixSI prefixThe International System of Units specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol...