I wonder if there have been any truly physically-gating dependencies? Meaning, physical and natural phenomenon where certain advances were impossible before they happened? For instance, certain technology that absolutely could not have existed before, say, a certain comet flew past because before then there was no evidence to believe X. Is there any reason to believe that we couldn't have been at this technological level 1,000 or 10,000 years ago?
This isn't technology, but the supernova of 1987 [0] confirmed our understanding of supernova physics, and gave us useful bounds on the mass of the neutrino. Even today, it gives stringent constraints on new hypothetical particles, which would have changed how the supernova played out. Unfortunately, we might have to wait decades to centuries for the next one.
Things getting cool enough after the big bang seems to be the obvious one.
But on a more serious note, maybe modern encryption? The physical gate being the literal ability to get rocks to count fast enough to finish decrypting something before the heath death of the universe
I'd actually put modern crypto in the opposite bucket: there's virtually no physical constraints at all. You could do RSA by hand if you had to, and if nobody else has computers, you can pick a key size small enough for doing it manually to be practical.
Oh I agree. I guess I was approaching this from the angle of the use of long keys where it would be literally impossible to decrypt unless computers exist.
We could also get into the sub argument of math being a property of the universe. Does encryption exist if we don't discover it? Trying to imagine a universe where our concept of math is impossible to the universe just not working that way
The two supernovae that Tycho Brahe and Kepler witnessed in a fairly close interval certainly helped to disprove the aristotelian notion that nothing could change in translunar space !