The last Greek letter, used for angular velocity — and the source of the ohm sign.
Also known as: Greek letter omega, Lowercase omega, Angular velocity symbol, ω, Last letter symbol
Omega is the final letter of the Greek alphabet, which is why it stands for endings and last things. In science its lowercase form is angular velocity; its capital form was borrowed to become the ohm sign, which the catalogue records as a separate symbol.
Is a letter of the Greek alphabet before it is a symbol: what it denotes is fixed by the field it appears in, not by the character itself. The uses below are the documented conventions, not competing definitions.
Contexts: Mathematics
In mechanics, denotes angular velocity — how fast something rotates.
Contexts: Mathematics
In electronics, denotes angular frequency in an alternating-current circuit.
Contexts: Mathematics
In electrical engineering, denotes electrical resistance in ohms, in its capital form.
Contexts: Mathematics
In set theory, denotes the first infinite ordinal number.
Contexts: Mathematics
Stands for the end or the last of something, from its position as the final letter — the sense in the phrase 'alpha and omega', meaning first and last.
Contexts: Mathematics
Has a capital form that Unicode encodes twice: once as the Greek letter and once as a separate ohm sign, kept distinct for compatibility although they are drawn identically.
Two visually identical characters that do not match each other in search or sorting — the same trap as the micro sign.
Contexts: Mathematics
A shape like a rounded w, or in its capital form a near-closed ring standing on two small feet.
The ohm sign is the capital of this letter, encoded separately in Unicode and drawn identically. Whether a capital omega means resistance or the letter depends entirely on where it appears.
Alpha and omega are the first and last letters of the Greek alphabet, and are paired to mean beginning and end.