Equivalence Principle Tests

The Weak Equivalence Principle is the principle of nature which states that the gravity behaves as if the observer were on a surface which was accelerating upwards.

The Equivalence Principle assumes a constant 1g acceleration:

Johannes Fankhauser at the University of Oxford says:

Physicists also often assume a uniform gravitational field. Professor Vincent Buonomano at the State University of Campinas states:

Searching for Extra Dimensions
From the introduction of Searching for Extra Dimensions and New String-Inspired Forces in the Casimir Regime (Archive), its authors Dr. Dennis E. Krause (bio) and Physics Professor Ephraim Fischbach (bio) tell us:

Universality of Free Fall
The Newtonian gravitational constant: recent measurements and related studies By George T Gillies

Full Text Link (Archive)

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'''5. Searches for variations in G 5.1. Spatial dependence of G'''

The above says that searches for departures from the inverse square bahavior of Newtonian gravity would be a violation of the Equivalence Principle which says that gravity is indistinguishable from an experiment which takes place on an upwardly accelerating Earth or compartment.

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It should be noted that 500 meters is 1640.42 feet, and about as high as the Shanghai World Financial Center, a skyscraper in China.

Inverse Square Behavior
The 'inverse square law', the 'Universality of Free Fall,' and the 'Weak Equivalence Principle' refers to the 9.8 meters per second squared rate of acceleration. From Foundations of Modern Cosmology we see a description of the inverse square law and how Newton interpreted the phenomenon in coming up with his theory of gravity:

Encyclopedia Britannica
Encyclopedia Britannica has provided an article on the experimental study of gravity. Aside from the gravimeter devices which have been shown to be seismometers (See: Gravimetry) and the Cavendish Experiment, which is an inconsistent short range experiment, Encyclopedia Britannica agrees that there are no variations in gravity:

https://www.britannica.com/science/gravity-physics/Experimental-study-of-gravitation (Archive)

Torsion Balances
On the topic of the Torsion Balance tests discussed above which attempted to measure the gravitation of the sun, Encyclopedia Britannica says:

Conclusion
The Britannica article concludes: