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

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

From Science Magazine

The team behind the research wanted to test a component of Einstein's theory of general relativity called the weak equivalence principle, which states that all objects, regardless of their mass or composition, should free-fall the same way in a particular gravitational field when interference from factors like air pressure is eliminated.

From Scientific American

The team's results, which are the culmination of 20 years of research, revealed that acceleration in pairs of objects in free fall differed by no more than 1 part in 10^15, or 0.000000000000001, meaning they found no violations in the weak equivalence principle larger than that.

From Scientific American

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