Let’s say that it’s scientifically proven that ghosts exist. Would they then stop being supernatural and become natural, thus making it impossible to ever have proof of the supernatural?
To answer your title, no.
To answer your post, yes, pretty much (imo).
Why do your post and title have different (almost opposite) questions? Lol
They’re not different questions in my head (I guess because I have all the context of what I’m thinking and just expressed myself badly).
I’m coming at this entirely from a philosophical point of view. I’m not asking if it’s technically possible to build a machine to prove the existence of the supernatural, but whether such a machine would change our categorisation of the now-proven thing
I wrote an article about exactly this: https://medium.com/@viridiangrail/tautological-denial-of-magic-0e311ca94c2a