When studying physics (simple stuff like electromagnetism and gravitational forces) I always wondered how the universe "knows" what's the distance between two planets when it comes to calculating forces amongst them. If the data (the distance) actually exist, where is it stored? Is it perhaps calculated "on the fly" so it doesn't need to be "stored"?
Totally sure that's not how it works in real life, but for us humans, that model is the best theory we have so far, so it's difficult to think differently.
Good question; I think the answer from general relativity is that it doesn't, and that those changes are propagated out locally at the speed of light. So it's a Newtonian fudge to have variables like "distance between two bodies" in the equations.
Mass changes spacetime curvature, and spacetime curvature pushes masses around, back and forth in a grand dance!
I definitely don't know much about general relativity, but isn't it yet another model/theory? A better one I bet, but one that still relies on information, so when we talk about "mass changes spacetime...", well my question remains: "how does the universe know, for instance, the mass of the sun in order for the universe to allow the deformation of spacetime that the sun causes?" I know it's probably not a rational question, but I used to ask that question to myself when I was a student.
Moving to a field theoretic model is precisely what allows you to abstract away at least some of those questions.
Space-time is distorted by energy, rather than just mass, which reduces the number of things the universe has to be prescient to. We can further eliminate some more prescience, by thinking in terms of density rather than mass: The laws of physics stated locally require only (say) a number and a field, rather than a pesky integral.
"Space tells matter how to move,
Matter tells space how to curve"
And asking these questions is a good thing. I've been sitting down and really thinking about special relativity recently, it's fun going through old papers and seeing about how to
derive the algebra in the most smugly experiment-less way.
On of the (self-admitted) flaws in Newton's conception of gravity is that it's in terms of forces (or potentials) that act across large distances; it's part of his "hypotheses non fingo".
One of the philosophically more pleasing things about GR is that it is local. But, of course, Newton's conception is a small-mass / low-velocity limit, so how can that be?
GR says that the effect of stress/energy at a place x changes the metric at that place. But the metric is something made of derivatives, so the space in some small neighborhood (this is the local part) nearby gets deformed. That deformation is itself a form of stress, and so places in the neighborhood of x effect places THEIR neighborhoods and so on.
So there's nothing built-in that's long-distance. Big long-distance effects are built up out of everybody talking to their immediate neighbors.
When studying electronics I fell down the rabbit hole. Electricity and magnetism are inseparable. I knew of EMF but why did magnetism push something, where did the magnetism come from, what are domains, how is magnetism emitted from domains, how are the atoms involved, what are virtual particles...and so on.
When really as an electronics technican all I needed to know was magnets can move things.
My understanding is probably also incorrect / incomplete, but I use the "trampoline" mental model where objects on the medium both update and react too the local geometry, ex. a tennis ball will roll towards the bowling ball, but doesn't "know" about the bowling ball.
Though it begs the question _how_ a given particle has read/write privileges with the geometry.
Totally sure that's not how it works in real life, but for us humans, that model is the best theory we have so far, so it's difficult to think differently.