When my dad was a student at Cal back in the 60's, the engineering department got it's first microwave. They though it would be a great idea to use it to dry mud from the SF bay, which they used to do experiments on. So they put some mud in there. No one knew how long to set it for, so they set it for a half hour and walked away. When they came back after a while, all you could see through the window of the microwave was a white glow. The mud had gone completely molten and was white hot. The microwave was melted straight to the counter. They didn't get in trouble because no one had knew any idea how to work the thing, even the profs.