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In our world, classical mechanics (Newton + Maxwell and their logical implications) holds for most everyday experiences at slow speeds (relative to the speed of light) and at scales larger than the atomic realm.*
Question: Is this necessarily true for every possible world that matches our macroscopic physical observations? Is it possible to construct an alternative set of physical laws such that the world would function exactly as our world does on a macroscopic, everyday level, but that would violate Newton's laws or Maxwell's laws or thermodynamics or the like? Again, I'm not talking about violating those laws in extreme cases (close to the speed of light, tiny scales) where these laws don't really apply even in our world. I'm talking about a world where even the everyday approximate equations of physics, as expressed in classical mechanics, do not apply.
Said another way: If you messed with Newton's equations or Maxwell's equations or thermodynamics even a little bit, would the world necessarily function differently in such a way that we could tell that you'd messed with the laws? Would it function so differently as to be unrecognizable?
Or said yet another way: Do our macroscopic experiences entail that the equations of classical mechanics are at least a very good approximation of the underlying physics?
I'd especially appreciate sources / references / links to further reading.
[*Leaving aside the types of modern technology which bring quantum mechanical effects into the everyday observable world.]
I may not understand the question's point, because as I read it the answer is a very obvious "Yes." We determined Newton's laws and Maxwell's equations from observations of our world. So the planets in orbit around the sun, the moon around the earth, and an apple falling to the ground all lead to gravitation. The attraction between wires carrying current in the same direction (magnetic), the functioning of transformers (change in magnetic field produces electric field) and radio and light all fit together to give Maxwell's equations.
So yes, ... (read more)