The experiments that lead to the invention of quantum theory are relatively simple and involve objects you can touch with your bare hands without damaging them. Some are done in high school, eg the photoelectric effect.
Whereas I did hedge my point regarding macroscopic quantum phenomena, I think that the quantum nature of the photoelectric effect would have been harder to discern without modern access to pure wavelength lighting. But you could still rely on precise optics to purify mixed light I suppose. But without even optics it should be even harder.
Whereas I did hedge my point regarding macroscopic quantum phenomena, I think that the quantum nature of the photoelectric effect would have been harder to discern without modern access to pure wavelength lighting. But you could still rely on precise optics to purify mixed light I suppose. But without even optics it should be even harder.