Hacker News new | comments | show | ask | jobs | submit login The Nuclear Potato Cannon, Part 2 (2006) ( nfttu.blogspot.com ) 40 points by ajarmst 3 hours ago | hide | past | web | 16 comments | favorite GlenTheMachine 9 minutes ago In grad school my advisor (who was teaching "Launch and Entry Systems") told us this story. A few lectures later he went over rail guns as a launch system, and mentioned that by his back-of-the-envelope calculations, a slug of titanium the size of a telephone pole, launched at earth escape velocity by a rail gun at sea level, would ablate approximately a third of its length away in the first thousand meters, or something close to that (it's been a long time). Actually calculating the heating of a steel plate launched at that speed is a significantly nontrivial problem, because its aerodynamics are unstable. In other words, it ...