Some of the highest precision manufacturing in our country is located in extremely rural areas because nearby highways introduce too much vibration otherwise. Even relatively humdrum spindle assembly is typically done in clean rooms to make sure no dust gets in the bearings. Super high precision machining is even more extreme. It's a wonderful thing to dive into but it also makes me happy to be in software sometimes. (That said, my friends in machining are happy they're not in software so take that as you will :)

Check out this classic text which is almost required reading for anyone working with precision mechanical stuff. It mentions ways to measure and machine parts down to millionths of an inch, and stuff like mills and lathes using temperature-controlled cutting fluid.

“Foundations of Mechanical Accuracy” Wayne R. Moore – 1970

https://archive.org/details/FoundationsOfMechanicalAccuracy

> Metrology is really fascinating.

It really is. I have some small experience with the industry, an acquaintance I didn't expect to have. The engineering that goes into metrology-grade measurement is incredible.