A youtube video that I get weirdly emotional about? I'm glad you asked!
It's this proof-of-concept by Clickspring that precision turned metal parts were totally possible with 2nd century technology, part of a larger project of making the Antikythera Mechanism with the tech of the time.
All the tools & parts involved were also made using the same "how they would/could have done it back then" approach.
I'd been following the channel for a bit before this but this video felt like a real culmination of effort, all the handmade tools converging to a spinning piece of bronze. When I saw the first chips come off the piece, it blasted me in the same way people talk about making mead or beer or bread or textiles. What I thought was possible machining-wise in relation to human history was totally recontextualized.
