# Testing the Equivalence Principle over the Centuries

**URL:** <https://scanalyst.fourmilab.ch/t/testing-the-equivalence-principle-over-the-centuries/3333>\
**Category:** Continuity\
**Tags:** gravitation, physics, equivalence-principle\
**Created:** [19 June 2023 15:10 UTC](https://scanalyst.fourmilab.ch/t/testing-the-equivalence-principle-over-the-centuries/3333 "2023-06-19T15:10:55Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![johnwalker](https://scanalyst.fourmilab.ch/user_avatar/scanalyst.fourmilab.ch/johnwalker/32/17415_2.png) [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Post date:** [19 June 2023 15:10 UTC](https://scanalyst.fourmilab.ch/t/testing-the-equivalence-principle-over-the-centuries/3333/1 "2023-06-19T15:10:55Z")

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[![](https://scanalyst.fourmilab.ch/uploads/default/original/2X/e/e8d169906e73d0648abeca9e7a92187ad6e228f7.jpeg "Mythbusted: Galileo’s Cannonball Drop..In Space!") ](https://www.youtube.com/watch?v=SfizyB02t-o)

The [equivalence principle](https://en.wikipedia.org/wiki/Equivalence_principle) states that two bodies will fall with the same acceleration under the influence of a gravitational field regardless of their composition. Tests of the equivalence principle have been reported from the 16th century with a precision in 5 parts per hundred to a [satellite experiment in 2017](https://en.wikipedia.org/wiki/MICROSCOPE) to one part in 10^{-15}.