radius vector

noun

, plural radii vec·to·res [vek-, tawr, -eez, -, tohr, -], radius vectors.

1. Mathematics. the length of the line segment joining a fixed point or origin to a given point.
2. Astronomy.
   1. the straight line joining two bodies in relative orbital motion, as the line from the sun to a planet at any point in its orbit.
   2. the distance between two such bodies at any point in the orbit.

radius vector

noun

1. maths a line joining a point in space to the origin of polar or spherical coordinates
2. astronomy an imaginary line joining a satellite to the planet or star around which it is orbiting

radius vector

1. A line segment that joins the origin and a variable point in a system of polar or spherical coordinates.
2. The imaginary straight line that connects the center of the Sun or another body with the center of a planet, comet, or other body that orbits it.

Word History and Origins

Origin of radius vector¹

First recorded in 1745–55

Example Sentences

The line drawn from the sun to any point of the orbit (the string from pin to pencil point) is a radius vector.

From Project Gutenberg

The radius vector of each planet moves over equal areas in equal times.

From Project Gutenberg

The radius vector (or line joining sun and planet) sweeps out equal areas in equal times.

From Project Gutenberg

Airy wrote expressing his interest, and asked for particulars about the radius vector.

From Project Gutenberg

This circumstance occurs, among other occasions, in the case of a radius vector in geometry, and diverging forces in mechanics.

From Project Gutenberg