Studying that one thanks, I remember seeing a liquid nitrogen demonstration as a kid before YouTube existed where they cooled the brass ball then it
fit through the ring, that was impressive.
An idea I had was using a solar to do the tunneling
https://www.youtube.com/watch?v=svAPyyUJUCo
Focus solar on a spot then have a system like in the produce section to periodically spray water to hopefully break off a little. Slow but with solar
tracking and automation I imagine it could do all the work with little input.
[Edited on 29-6-2017 by curiosity_cat] |