An Etymological Dictionary of Astronomy and Astrophysics
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Of or relating to René → Descartes, his mathematical system, or his philosophy, especially with regard to its emphasis on logical analysis and its mechanistic interpretation of physical nature. → Cartesian coordinates; → Cartesian vortex theory.

From L. Cartesianus, from Cartesius, Latinized form of the name of French philosopher and mathematician René Descartes (1596-1650), + suffix -ian.

A → coordinate system in which the position of a point is specified by two (in a plane) or three (in 3-dimensional space) → real numbers representing the distances from two perpendicular axes or from three perpendicular planes, respectively. René Descartes (1596-1650) introduced the coordinates system in his La Géométrie in 1637.

→ Cartesian; → coordinate.

A mechanical model put forward before Newton's theory of gravity to explain the revolution of the planets around the Sun. Descartes in his 1644 Principia Philosophiae postulated that the space between the Sun and the planets is filled with matter in the form of a fluid. The fluid rotates in countless whirlpools, one for each planet, thus carrying the planets along in their flow. The vortices vary in size and are contiguous as well as nested. Descartes believed that two objects can exert force on each other only when they are in physical contact. This is why he postulated that space is filled with matter. Newton refuted the vortex theory, using the principle of → action at a distance on which relies his → law of universal gravitation.

→ Cartesian; → vortex; → theory.