, lowercase μ
; Μι or Μυ [mi]) is the 12th letter of the Greek alphabet
. In the system of Greek numerals
it has a value of 40. Mu 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 Mem
. Letters that arose from Mu include the Roman M
and the Cyrillic letter М
The word Mu
, pronounced /muː/ or /mjuː/ in English, is written μῦ in traditional Greek polytonic orthography
. In Modern Greek
the ancient version is sometimes written μύ.
In Modern Greek, the name of the letter is spelled μι and is pronounced [mi].
The letter Mu appears in conjunction with alpha
to signify the "beginning, middle (meson
) and end", a phrase found in an Orphic
verse describing Zeus
, and later adopted to describe both JHWH
In Aeschylus' Eumenides, the repeated moaning of the letter Mu is the sound made by the sleeping Furies as the ghost of Clytemnestra begins to invoke them. It again appears as an ominous mantra in a 10th century Coptic papyrus, containing a Christian injunction against perjurers that invokes the angel Temeluchos:
- I adjure you by the seven perfect letters, ΜΜΜΜΜΜΜ. You must appear to him, you must appear to him. I adjure you by the seven angels around the throne of the father.
The lower-case letter mu is used as a special symbol in many academic fields. The upper case Mu is not generally used in this way because it is normally indistinguishable from the Latin M.
In Unicode, the upper and lower case mu are encoded at 039C and U+03BC respectively. In ISO 8859-7
they are encoded at CCHEX
. The micro sign
is considered a distinct character
from the Greek alphabet letter by Unicode for historical reasons (although it is a homoglyph
) and is found at U+00B5 as well as position B5HEX
in ISO 8859
, and thus in the corresponding Windows code pages Windows-1252
also has a character that looks somewhat like lower case mu at E6HEX
but this is actually supposed to be the Cyrillic small letter tse
When Alt-0181 or the DOS legacy Alt+230 or Alt+(any multiple of 256 added to 230 or to 0181 and including the leading zero) is typed into an editable field using the number pad in Microsoft Windows, the µ symbol appears. Also if AltGr + M is pressed you get µ.
In HTML code, the µ symbol is represented by "µ" and "µ".
Because µ is the abbreviation for the Metric System prefix micro-, the symbol is used in many word plays about the field of micro-computing. For example, the symbol is used in the name and logo of the popular bittorrent client, µTorrent. It is sometimes simply substituted with a u, the most likely looking ASCII glyph, eg. uTorrent.
- Mike Paradinas, a British electronic musician, uses the letter in his stage name μ-ziq (pronounced music), as well as in the name of his record label Planet µ, often written Planet Mu.
- Typing the numbers (4,8,15,16,23,42) from the fictional TV series Lost resulted in the character "µ". In Microsoft Windows, holding down the "Alt" key while entering these numbers results in the character appearing wherever your cursor is (though the 4 and 8 are superfluous).
- Moralia, by Plutarch
- Ancient Christian Magic, by M. Meyer and R. Smith (ed.), Princeton University Press, ISBN 0-691-00458-7