You also have fun effects due to temperature, humidity, vibrations, heat radiation, etc. This means that large sheets produced in those precisions will still bend and all that, making the smoothness a bit absurd.
That said I could imagine that he mistranslated something his usability haptic researchers did tell him, that hands can detect irregularities up to 9 microns. Those numbers are relevant for how smooth surfaces have to be that people regularly touch. Still even in that most generous case it is a bit absurd, especially when we see Tesla's shoddy current construction.
You also have fun effects due to temperature, humidity, vibrations, heat radiation, etc. This means that large sheets produced in those precisions will still bend and all that, making the smoothness a bit absurd.
That said I could imagine that he mistranslated something his usability haptic researchers did tell him, that hands can detect irregularities up to 9 microns. Those numbers are relevant for how smooth surfaces have to be that people regularly touch. Still even in that most generous case it is a bit absurd, especially when we see Tesla's shoddy current construction.