Mew ( uppercase MEW, lowercase μ; Ancient Greek μῦ, or μυ—both ) is the twelfth letter of the Greek alphabet, representing the voiced bilabial nasal. In the system of Greek numerals it has a value of 40. Mew was derived from the Egyptian hieroglyphic symbol for water, which had been simplified by the Phoenicians and named after their word for water, to become 𐤌 mew Letters that derive from mu include the M|Roman M and the Cyrillic М, though the lowercase resembles a small U|Latin U (u).

Names

Ancient Greek

In Greek, the name of the letter was written μῦ and pronounced.

Modern Greek

In Modern Greek, the letter is spelled μι and pronounced. In polytonic orthography, it is written with an acute accent: μί.

Use as symbol

The lowercase letter mu (μ) is used as a special symbol in many academic fields. Uppercase mu is not used, because it appears identical to Latin M.

Prefix for units of measurement

"μ" is used as a unit prefix denoting a factor of 10−6 (one millionth), in this context, the symbol's name is "micro".

Mathematics

"μ" is conventionally used to denote certain things; however, any Greek letter or other symbol may be used freely as a variable name.

Physics and engineering

In classical physics and engineering: In particle physics: In thermodynamics:

Computer science

In evolutionary algorithms: In type theory:

Chemistry

In chemistry:

Biology

In biology:

Pharmacology

In pharmacology:

Orbital mechanics

In orbital mechanics:

Music

Cameras

The Olympus Corporation manufactures a series of digital cameras called Olympus μ (known as Olympus Stylus in North America).

Linguistics

In phonology: In syntax: In Celtic linguistics:

Unicode

The lower-case mu (as "micro sign") appeared at in the 8-bit ISO-8859-1 encoding, from which Unicode and many other encodings inherited it. It was also at in the popular CP437 on the IBM PC. Unicode has declared that a "real" mu is different than the micro sign. These are only to be used for mathematical text, not for text styling:

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