Illustrative story: I have over the years built a high-precision measurement capability, but with a commitment to avoid batteries and software. That means I have acquired vernier calipers, outside micrometers, bore gauges, inside micrometers, dial indicators, dial test indicators, gage blocks, precision squares and parallels, a precision granite surface plate, depth micrometers, master bores, and so on. Here’s the joke (and the joke is definitely on me): I really don’t have anything I need to measure at that level of precision (and I can measure stuff to 0.0001” and some things to 0.00005”). Why in the world would I have that stuff? On occasion I do need it, and I relish the skill to use it, for no other reason than the joy of expressing that skill.
These days, a machinist will use a digital micrometer that requires no special skill to read, but I had no interest in that. He won’t even need that, because he’ll trust his CNC mill and lathe. Maybe it’s a character flaw. But it sure gives me insight into what prior generations could do. We went to the moon with those old Etalon, Starrett, Interapid, and Brown & Sharpe calipers and indicators. And the insight that stuff gives me includes, among other things, an intimate understanding of significant figures and the difference between accuracy and precision. Those principles are often lost on those using 10-digit calculators to dimension stuff that can only be made accurately enough to need three.
Rick “science and history get along just fine” Denney