Gravitational fields have different strengths at different distances from mass-energy. In gravitational fields, objects have different forces {tidal force} on side nearest to mass-energy, side farthest from mass-energy, and middle. Tidal distortions depend on gravitational-field strengths at different space points.
Gravity varies inversely with distance squared {inverse square law}, so tidal effects vary inversely with distance cubed (by integration). Therefore, tidal effects can measure gravitational-field strength.
See Figure 1. The larger object is denser and has much more mass than smaller object. The smaller object is fluid. The objects are not far apart.
near and far
Gravitation pulls smaller-object nearer side, farther side, and middle straight toward larger-mass center. Nearer side feels strongest gravity, and its particles accelerate most. Middle feels intermediate gravity, and its particles accelerate intermediate amount. Farther side feels weakest gravity, and its particles accelerate least. Along vertical, small object tends to stretch out from middle, keeping same volume.
left and right
Gravitation pulls left and right sides toward larger-mass center diagonally, straight down along vertical component and across inward along horizontal component. Left and right sides feel slightly less gravity than middle, because they are slightly farther away from larger-mass center. Those particles accelerate downward slightly less than middle does. Left and right sides also accelerate small amount horizontally toward smaller-mass center. This pushes other molecules equally up and down and contributes to vertical stretching out.
waves
Changing gravity changes tidal forces and can cause mass oscillations. Mass accelerations make gravitational waves.
Physical Sciences>Physics>Relativity>General Relativity>Gravity
5-Physics-Relativity-General Relativity-Gravity
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Date Modified: 2022.0224