Retro Futurism: Is That a Magnetron Tube In Your Pocket or Are You Just Happy to See Me?: "One day in the mid-1940s, Raytheon employee Percy Spencer was working with an active radar set when he noticed that a candy bar in his pocket had melted. Spencer got some popcorn, put it in proximity of the magnetron tube that generated the microwaves for the radar, and was soon enjoying a tasty snack."
More often then not it seems as though great moments in science are preceded by the words,"That's funny..."
Something we don't see so much anymore is the free wheeling setups anymore, Nowadays things are so "safe" that it is hard for accidental discoveries to happen. It is a mixed blessing. I certainly don't wish for people to be injured doing things but repurposing things is hard if you can't experiment easily.
I remember when food processors got really safe. Even TV chefs had problems getting them going making sure that all the pieces in the right place and in the right sequence. There was one guy that looked like he was going to rip it apart before getting it to work.