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Newton's law of gravitation

The pull between worlds.

Every mass attracts every other mass. Drag the two masses or the distance between them — double the distance and the pull falls to one quarter.

F = Gm1m2 r2
Mass 1 m1 m1 ∝ F
1 gperson · planet · star10³¹ kg
Mass 2 m2 m2 ∝ F
1 gperson · planet · star10³¹ kg
Distance r r⁻² ∝ F
1 mdouble r · a quarter the pull~3.3 AU
Gravitational force
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Newton's law of universal gravitation says every pair of masses attracts with a force proportional to each mass and inversely proportional to the square of the distance between their centres, with G = 6.674 × 10⁻¹¹ N·m²/kg² fixed by nature. The two circles in the diagram are symbolic — their sizes show relative mass only loosely, not physical scale, since real masses here span more than thirty orders of magnitude.