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I'm reading the definition of the principle of locality from its Wikipedia page:

The principle of locality states that an object is influenced directly only by its immediate surroundings.

This definition makes sense to me, but I wonder can we interpret this using some common examples in physics? I heard about General Relativity is local. Can I interpret this as any object with mass will cause the curvature of spacetime, which are immediate surroundings that influence the trajectory of the planets? Also, how does the principle of locality is related to action at a distance?

IGY
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The principle of locality is an axiom which asserts that the time it takes for one system to affect another will always be mediated by the distance between them. What general relativity being local means is that no information coming from a system (eg: changes in spacetime curvature/gravity) can propagate faster than the speed of light. Any object with mass (eg: the sun) will curve spacetime, but the time it takes planets to detect any spacetime changes depends on the time it takes for light to travel from point A to point B (which is around 8 minutes between the sun and the Earth).

Unmaxed
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It's a tautology, obviously an object can only directly be affected by its immediate surroundings.

Picture a table filled with billiard balls and you hit one ball at a time. That struck ball may cause several consequent collisions but only the collisions involving the initial struck ball are directly affected by that ball and only when in the immediate environment of that ball.

fertilizerspike
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