equivalence principle


noun Physics.

(in relativity) the principle that, in any small region of space-time, the effects of a gravitational field are indistinguishable from those of an appropriate acceleration of the frame of reference.
Also called Einstein's equivalency principle, principle of equivalence.

Origin of equivalence principle

First recorded in 1915–20

Scientific definitions for equivalence principle

equivalence principle
[ ĭ-kwĭvə-ləns ]

A principle central to General Relativity stating that a gravitational field is locally indistinguishable from the effects of inertial forces. For example, according to the equivalence principle, it is impossible for someone in a box who experiences a force pushing him to the bottom of the box to know, from the force alone, whether that force is the result of a gravitational field (the box is standing on the surface of a planet) or an acceleration (the box is being pushed by a rocket).