As a home engineer that rebuilds lathes, mills and other highly accurate machines down to the micron level (1/1000th mm) the importance of having everything at the same temperature when rebuilding is of the utmost importance.
All my test kit; block gauges, micrometers, 300kg surface plate, engineers levels, sine bars etc are calibrated at 20'c (the industry standard) .. one of the best ways to see the effect temperature has on accuracy is to warm one side of an engineers level in your hand then place it on a surface and watch the bubble move as the temperature equalizes.
I know how to run a lathe and vertical mill, but would love to learn more about any of the topics you mentioned. It sounds more involved than what you'd find in a normal maintenance shop. Any suggestions to learn more about this? I didn't know that people even rebuilt lathes and mills.
Outside of '01-JAN-1999', I am forever Googling "TO_DATE Oracle" because the string formats for precision time stamps always turn out to be counter-intuitive, and the exact opposite of what I expect.
I found ISO 2 to be even more interesting, the second international standard is... yarns? Or rather, the directional twist of yarns? https://en.wikipedia.org/wiki/ISO_2
If I'm not mistaken, ISO makes most of its money not from member contributions but from selling paper copies of the standards. Speaking cynically, perhaps they needed a way to ensure their clients (libraries, companies, governments) will pay for "updates".
All my test kit; block gauges, micrometers, 300kg surface plate, engineers levels, sine bars etc are calibrated at 20'c (the industry standard) .. one of the best ways to see the effect temperature has on accuracy is to warm one side of an engineers level in your hand then place it on a surface and watch the bubble move as the temperature equalizes.