Re: 3700 year ago ... and before then?
This is a misconception. Based on long timescales it was "over night", but a LOT of the math and theory for GR and QM were already there. Einstine was around for the finalling of the theory, the observation of evidence, but his work was built on the backs of giants.
But those are two examples of very fine detail observations and mechanics. Building and construction, astronomy and planetary path prediction, medicine and health are all things every day people can make observations with. Math including. Which means it can get independent discovery, or just plain "common knowledge" use (such as Aboriginals in Australia not knowing what bacteria is, but knowing not to kill and eat meat near the camp for risk of disease).
Biting the hand that feeds IT
