Since people never learn that me + expensive equipment = a bad idea, recently I've started lessons at school in learning how to use the scanning electron microscope (the SEM), which is way cool because you can see individual atoms with it. Basically, it shoots a bunch of electrons at a sample, but if the sample doesn't conduct electricity, then the electrons will just sit on it instead of going through it and creating an image to look at. So before looking at a sample, you have to coat it in gold.
When I first learned this, I pictured some vague process of dumping gold on the sample, but of course, it's much more complicated than that. It involves this whole thing with argon gas and particles and the like, but when it comes down to it, you stick the sample on a peg-like thing, you stick the peg-like thing on a platform, you stick a jar over it, and you let gold essentially fall on it.
This whole thing happens on a machine with this screen where you press the right buttons. And yes, I managed to mess this up. In my defense, the screen was very small and I was very nervous.
"Release the gas valve, and stop it at 50 millitorres," the instructor instructed in an instruct-y way as instructors are wont to do.
I squinted at the little grainy buttons and hit the one that said "Open Gas Valve", and watched as gas floated into the little jar. So mesmerized was I by this spectacle, I didn't notice that the pressure was dropping swiftly from 100 millitorres, to 80 millitorres, to 50 millitorres, and past.
I continued to watch the gas when a fellow student jabbed me on the arm and hissed, "Look at the screen!"
I tore my gaze away and stared at the screen, eyes wide, where it displayed "20 millitorres". I leaped forward and stabbed the screen until the gas valve closed, and looked up to see the instructor looking down at me with the most disapproving expression in the history of the human race.
I may have wasted several ounces of gold.
Well, next week I get to use the actual electron microscope! That can only end well!