*World of Physics*. ©2005-2006 Thomson Gale, a part of the Thomson Corporation. All rights reserved.

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Physics is an experimental science, an therefore a science of measurement. Of all possible measurements, the most fundamental is position. To quantitatively locate an object in **space** (or **space-time**) requires a coordinate system (CS). The choosing of a coordinate system is nothing more than the assignment of a label to each point in space. (In general, such a label is an *n*-tuplet of numbers, where *n* is the dimension of the space. Thus it requires three numbers to label a point in space, and four numbers to label an event in space-time.) In order to compare measurements between coordinate systems a set of equations relating the two different labels assigned to the same physical point is required. These relations are known as "coordinate transformations."

The simplest CS is the well-known Cartesian system, with three orthogonal (mutually-perpendicular) axes, usually labeled *x*, *y*, and *z*. It is not always...

This section contains 632 words(approx. 3 pages at 300 words per page) |