Nor can anyone explain the sudden rush of scientific advances in the late middle ages.
Scientific and medical knowledge compiled by the Greeks and Romans did not change for over a thousand years, then all of a sudden knowledge exploded. Why? Divine intervention?
Archeologists found a small toy steam engine built by the Greeks. Why didn't the Greeks or Romans look at it and think to use it for something other than a toy? Why 1500 years later out of nowhere did mankind suddenly decide to put that steam power to work to make life easier? Why did doctors for over a thousand years rely on the Greek books of medicine and make no inquiries or advances on their own? Why all of a sudden did mankind decide to do it in the late middle ages? Divine Intervention?
Sometimes things "just happen".
Things never just "happen".
In the meantime, follow the money (rewards, sponsorship, broads...), and enabling technologies (communications, colleges, manufacturing...)
[I'm probably a determinist]