I interned at a great company (https://qedmrf.com/ https://qedmrf.com/) that engineers magnetorheological fluid and machines for polishing / analyzing optics.

I interned at a great company (https://qedmrf.com/ https://qedmrf.com/) that engineers magnetorheological fluid and machines for polishing / analyzing optics. I can't imagine doing it by hand. Fascinating stuff.