Comment by SAI_Peregrinus

Nothing intellectually, but some things are financially, spatially, and/or temporally out of reach. A long term goal of mine has been to make machines which are decently precise with wide dynamic range measurement capabilities for all of the SI base units & some commonly-used derived units. Somewhere in the 6-8 digits of dynamic range for each.

E.g. be able to measure distances over a 50cm range to a resolution of ±500nm. Easy for a coordinate measuring machine, very challenging and expensive to DIY.

Validating anything I build means finding a calibration lab willing to check it, which is also rather pricey. I don't have the space, the time, or the money to do this.