From Textus Receptus
Mu (uppercase Μ, lowercase μ; Ancient Greek μῦ mŷː), Modern Greek 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 (𓈖) which had been simplified by the Phoenicians and named after their word for water, to become 𐤌. Letters that arose from mu include the Roman M and the Cyrillic letter М.
In Ancient Greek, the name of the letter is written μῦ and pronounced mŷː|.
- the µ-roots of a complex number z = a + bi
- the Möbius function in number theory
- the integrating factor in ordinary differential equations
- the population mean or expected value in probability and statistics
- a measure in measure theory
- minimalization in computability theory and Recursion theory
- the learning rate as used in artificial neural networks
- the SI prefix micro-, which represents one millionth, or 10−6.
- the micron, an old unit which corresponds to the micrometre (which is now denoted "µm")
Physics and engineering
- the coefficient of friction (also used in aviation as braking coefficient)
- reduced mass in the two-body problem
- linear density or mass per unit length in strings and other one-dimensional objects.
- permeability in electromagnetism
- the magnetic dipole moment of a current-carrying coil
- dynamic viscosity in fluid mechanics
- the amplification factor of a triode vacuum tube
- the electrical mobility of a charged particle
- the airspeed relative to rotor tip speed, in rotorcraft
In particle physics:
- the chemical potential of a system or component of a system.
- an important opiate receptor
- Standard gravitational parameter of a celestial body, the product of the gravitational constant G and the mass M.
- planetary discriminant, represents an experimental measure of the actual degree of cleanliness of the orbital zone, a criterion for defining a planet. µ is calculated by dividing the mass of the candidate body by the total mass of the other objects that share its orbital zone.
In application names:
The Olympus Corporation manufactures a series of digital cameras called Olympus µ[mju:] or Olympus Stylus.
In Unicode, the upper and lower case mu are encoded at 039C and 03BC respectively. In ISO 8859-7 they are encoded at CCHEX and ECHEX. In HTML code, the μ character is represented by "μ", "μ" and the entity "μ".
The micro sign or micron 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 8859-1, 3, 8, 9, 13 and 15, and thus in the corresponding Windows code pages Windows-1252 etc. In HTML code, the µ symbol is represented by "µ", "µ" and the entity "µ". When Alt-0181 or the DOS legacy Alt+230 is typed into an editable field using the numeric keypad in Microsoft Windows, the µ symbol appears. Also pressing AltGr + M results in a µ on some keyboard layouts.
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. Also, the microcontrollers are commonly represented in schematics as µC. It is sometimes simply substituted with a u, the most similar-looking ASCII glyph, eg. uTorrent.
1.^ Olympus History : (Stylus) Series