Just remembered this one (also science-related)
When I started the second year of college, our A-level Physics class got a new teacher - a librarian-type fresh out of university, generally nervous and inexperienced, and she wasn't totally sure of what she was supposed to be teaching us. She often lost her temper because we hadn't learned something that wasn't going to be in the course for another six months. Practicals were even better - she'd give us some hideously convoluted experiment to do, and we'd ignore it completely and piss about with the apparatus instead. She didn't feel up to arguing with 14 hulking great lads, so she just let us get on with it.

Out of these experiments, the best one was where we had to construct an electromagnet and ferkle around with it in some way. Well, we made the electromagnets all right, but instead of doing whatever it was we were supposed to do, we made some of our own observations on what would happen if eg. you put 12 volts through it instead of 3, or if you just wound one coil of wire round the metal instead of fifty. It was certainly educational! That lesson was punctuated by miniature fires, the smell of burning plastic, clicks and clacks as we tripped all the fuses, and our teacher's wailing howls of frustration.

Frankly, that was as interesting as physics ever got.

PS: someone earlier reckoned fire was a chemical reaction - it's the by-product of reactions, not a reaction in itself. The reason fire doesn't burn in a vacuum is that there are no air molecules to be split by the energy released from a chemical reaction (this is where all the light and heat of fire comes from.) Apologies for pedantry etc.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Fri 4 Nov 2005, 14:41, Reply)