equivalence principle

American  

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.

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equivalence principle Scientific  

/ 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).

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Etymology

Origin of equivalence principle

First recorded in 1915–20

Example Sentences

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

From Science Magazine • Sep. 27, 2023

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 • Sep. 27, 2023

But for the Unruh effect, it’s a matter of acceleration—which is, per Einstein’s equivalence principle, gravity’s mathematical equal.

From Scientific American • May 20, 2022

For decades, experimentalists have verified the equivalence principle using exquisitely delicate instruments.

From Nature • Jul. 3, 2018

Einstein proposed the equivalence principle as the foundation of the theory of general relativity.

From Textbooks • Oct. 13, 2016