equivalence principle

noun

, Physics.

1. (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.

equivalence principle

/ ĭ-kwĭv′ə-ləns /

1. 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).

Word History and Origins

Origin of equivalence principle¹

First recorded in 1915–20

Example Sentences

According to the so-called equivalence principle, in a gravitational field all objects fall at the same rate regardless of what they’re made of.

From Science Magazine

Until now, however, nobody had tested whether the equivalence principle holds for matter and antimatter.

From Science Magazine

As well as placing constraints on deviations in the weak equivalence principle, the findings also disfavor any deviations in Einstein's 1915 theory of gravity, general relativity, as a whole.

From Scientific American

The fact the new research found no violation of the weak equivalence principle puts the highest constraints yet on this element of general relativity, and the results also lay the groundwork for even more sensitive tests in the future.

From Scientific American

A satellite implementing these improvements could potentially pick up violations of the weak equivalence principle as tiny as 1 part in 10^17, 100 times more sensitive than MICROSCOPE.

From Scientific American