My father once explained wave function collapse by saying that if you had a time machine, travelled back in time a given set of years, and then just parked your time machine totally removed from everything and didn’t interfere with anything, history would still in all likelihood play out differently, because there is no guarantee that the wave functions will collapse in the same way as they did the first time around.Indeed, great job Gary.
I've mentioned this before, but my main takeaway from reading Dale Cozort's (very interesting) AH timelines is he takes a fascinatingly fundamentalist approach to the butterfly effect. The TL might be about Spain colonising South Carolina, but then a few months later someone dies in the wrong duel back in Spain due to random chance and that has an impact on the Comuneros. Realistic from one POV but has no connection to the original POD. But the best example of this is how in his WW2 timelines, Hitler seems to almost invariably get assassinated a week after an unrelated POD - because his argument is that OTL is the outlier in that Hitler somehow managed to survive to the end of the war despite having so many constant assassination attempts. It's an interesting approach to say the least.