we tend to assume that knowledge and technology developments are a continuous, connected process but history shows they're not
- da Vinci’s discoveries about human anatomy and circulation, especially the heart, were only rediscovered centuries later (he never published)
https://www.bbc.co.uk/news/health-28054468
- concrete was used extensively by Roman engineers including underwater construction of ports and harbours, but this knowledge and technology - which is essential in our modern world - was lost for nearly two thousand years (disruption after the “fall of the Roman Empire”?)
http://engineeringrome.org/understanding-roman-concrete/
- the Antikythera mechanism, discovered 1901 in an ancient sunken shipwreck, was considered a prochronism and nothing like it has ever been found since. But it cannot have been the only example of such advanced engineering technology, and the associated knowledge needed to conceive it and to construct it has also been lost (all we have is references to other complex devices in various ancient documents that have survived)
https://talesoftimesforgotten.com/2019/12/24/no-the-antikythera-mechanism-was-not-unique/