One comment states: >Given full blueprints, you can reasonably rebuild any machine from 19-th century from scratch, no matter how complicated. Even if you star

One comment states: >Given full blueprints, you can reasonably rebuild any machine from 19-th century from scratch, no matter how complicated. Even if you start from raw materials. Wich is totaly untrue, not the blueprint was important but the handcraft knowledge, and that is often forgotten. Whe even had to relearn many details how appolo landed on the moon because of lost knowledge, and that thing was pretty good documented. Just one of many examples: https://www.sciencealert.com/why-2-000-year-old-roman-concrete-is-so-much-better-than-what-we-produce-today https://www.sciencealert.com/why-2-000-year-old-roman-concre...