Gotcha. So, assuming that the actual Isaac Newton didn't rise to prominence*, are you thinking that human life would usually end before his equivalent came around and the ball got rolling? Most of our existential risks are manmade AFAICT. Or you think that we'd tend to die in between him and when someone in a position to build the LHC had the idea to build the LHC? Granted, him being "in a position to build the LHC" is conditional on things like a supportive surrounding population, an accepting government, etcetera; but these things are ephemeral on the scale of centuries.

To summarize, yes, some chance factor would def prevent us from building the LHC as the exact time we did, but with a lot of time to spare, some other chance factor would prime us to build it somewhen else. Building the LHC just seems to me like the kind of thing we do. (And if we die from some other existential risk before Hadron Colliding (Largely), that's outside the bounds of what I was originally responding to, because no one who died would find himself in a universe at all.)

*Not that I'm condoning this idea that Newton started science.