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It occurs to me that the definition of 'force fields', such as gravitational fields, is circular.
When we ask "what is a force field?", we are told that it is a region of spacetime where some or other material object experiences a force. And when we ask "how/why does an object experience a force in some region of spacetime?", we are told that it is due to the presence of a force field.
But what is a force field "really"? In order to exert a force (whether pushing or pulling) on material objects, a force field needs logically to be the effect of some or other real, physical "goings on". But what? Do we have a mechanical, causal explanatory account of what a force field "actually" is?
More particularly, how can I understand (without ultimately appealing to some or other Einsteinian "spooky action at a distance") how, in the case of gravity for example, one physical object can remotely 'pull' another? To pull something, don't we need a line with a hook on the end?
I am familiar with Einstein's explanation in terms of warped spacetime; but as far as I can tell, that is just an instrumentalist account, with little causal explanatory power. Is there a better explanation?
The present does not seem to me to be an opportune time to enter
into the investigation of the cause of the acceleration of
natural motion, concerning which various philosophers have
produced various opinions ....
Such fantasies, and others like them, would have to be
examined and resolved, with little gain. For the present, it
suffices .... to say that in equal times, equal
additions of speed are made.
Galileo, _Two New Sciences_ (1638).