Scalar

Scalar is a concept that has meaning in mathematics, physics, and computing.

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The word scalar derives from the English word "scale" for a range of numbers, which in turn is derived from scala (Latin for "ladder"). According to a citation in the Oxford English Dictionary the first usage of the term (by W. R. Hamilton in 1846) described it as:

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:"The algebraically real part may receive, according to the question in which it occurs, all values contained on the one scale of progression of numbers from negative to positive infinity; we shall call it therefore the scalar part."

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Hamilton's usage actually describes his quaternion-based notation, which (in modern terms) represented rotations by a scalar, the real part of the quaternion, and vectors by the other three parts. Quaternions are widely used in spacecraft attitude determination and control, because they are not subject to the singularities of Euler angles and have only four components, while a rotation matrix has nine components to represent only three angles.

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Physics: Physics (from the Greek, φυσικός (phusikos), "natural", and φύσις (phusis), "nature") is the science of the natural world in the broadest sense, dealing with matter and energy and the fundamental forces of nature that govern the interaction...

Computing: Originally, the word computing was synonymous with counting and calculating, and a science that deals with the original sense of computing mathematical calculations....

Latin: Latin is an Indo-European language originally spoken in the region around Rome called Latium. It gained great importance as the formal language of the Roman Empire. All Romance languages are descended from Latin, and many words based on Latin are found in other modern languages such as English. The ...