Definition of equivalence principle in English English dictionary
any of several principles, in relativity, concerned with the uniformity of physical measurements in different frames of reference
Fundamental principle of physics that in its weak form states that gravitational (see gravitation) and inertial (see inertia) masses are the same. Albert Einstein's stronger version states that gravitation and acceleration are indistinguishable. It implies that the effect of gravity is removed in a suitably accelerated reference frame, such as an elevator with its cable cut, in which a person would experience free fall
(physics) the principle that an observer has no way of distinguishing whether his laboratory is in a uniform gravitational field or is in an accelerated frame of reference