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

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

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

From Science Magazine • Sep. 27, 2023

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 • Sep. 15, 2022

The accelerations of the two bodies differ by no more than 2.6 parts per million, in agreement with the equivalence principle.

From Nature • Jul. 3, 2018

By considering the consequences of the equivalence principle, Einstein concluded that we live in a curved spacetime.

From Textbooks • Oct. 13, 2016