Relative Direction
The most common relative directions are left, right, forward(s), backward(s), up, and down. No absolute direction corresponds to any of the relative directions. This is a consequence of the translational invariance of the laws of physics: nature, loosely speaking, behaves the same no matter what direction one moves. As demonstrated by the Michelson-Morley null result, there is no absolute inertial frame of reference. There are definite relationships between the relative directions, however. Left and right, forward and backward, and up and down are three pairs of complementary directions, each pair orthogonal to both of the others. Relative directions are also known as egocentric coordinates.
Read more about Relative Direction: Traditions and Conventions, Geometry of Natural Environment, Nautical Terminology, Cultures Not Using Relative Directions, Left-right Confusion
Famous quotes containing the words relative and/or direction:
“To revolt is a natural tendency of life. Even a worm turns against the foot that crushes it. In general, the vitality and relative dignity of an animal can be measured by the intensity of its instinct to revolt.”
—Mikhail Bakunin (1814–1876)
“When you know what men are capable of you marvel neither at their sublimity nor their baseness. There are no limits in either direction apparently.”
—Henry Miller (1891–1980)