I was just reading a sci-fi novel where physics "breaks down". While of course fiction is fiction and I don't expect this to happen in real life, when I tired to contemplate the concept I find that I cannot even imagine what it would mean for physics to break down. Is my imagination too limited or is such breakdown indeed impossible/undetectable? Apologies if this is outside of the scope of this SE, feel free to close if appropriate.
Let me try to narrow down the problem. I would like the everyday physics to remain the same - no planes falling down from the sky and bridges collapsing, etc. However, as we keep poking into more and more subtle subtle properties of our universe, the fundamental rule saying that repeating the same experiment should give the same results stops to be valid. In the story, this happened to particle physics: we build a few huge particle accelerators and it turns out that running the same experiment on different accelerators or at the same accelerators at different times gives different results. For simplicity, say we measure some value X (one real number) and depending on the time and location we get drastically different results.
What I don't understand is what possible measurement could make us think that physics no longer works. If X differs randomly, then we could classify this as random behaviour, measure average value, etc. - if I understand correctly, randomness is already is a fundamental feature of quantum mechanics and appears a lot in thermodynamics and other branches. If X varies in a structured way, then we could describe this structure and obtain a law of nature like any other. I don't think I could make a rigorous mathematical statement out of this, but it seems that any signal can be decomposed into a combination of something that looks random and structured for the purposes of physics. The worst I can think of is if X was supposed to be a constant, but I've heard that there are theories (maybe somewhat niche, but not ridiculous if I'm not mistaken) where the usual constants are not constant but vary slowly over time.
TL;DR Is there a conceivable results of a physics experiment that would make us conclude that physics has broken down?