Roughly similar craziness: Disk drives mechanically position heads less than 1nm above the platter, with horizontal accuracy of significantly less than the 50nm

Roughly similar craziness: Disk drives mechanically position heads less than 1nm above the platter, with horizontal accuracy of significantly less than the 50nm track width, at a retail price of a few hundred $$ or less. 30 years ago I think you could have gotten any number of experts to explain why both EUV lithography and modern disk drives are impossible.