> When I was a teenager, my dad and my brother Mike decided to make homemade chili. I'd never seen it made before, and I watched with keen interest as they added beef, beans, some veggies and spices, and other ingredients. Dad would taste it, add some more ingredients, wait a bit, taste it again. My dad has some pretty good recipes. So you can imagine my puzzlement when he opened the cupboard, pulled out 2 cans of Hormel chili, opened them and dumped them in. I waited a respectful moment or two before asking him why he was adding canned chili to his chili.
Similarly, I think it detracts a bit from building a home-made x-ray machine if one of the ingredients is an x-ray tube from an old x-ray machine.
[1] http://steve-yegge.blogspot.com/2006/10/egomania-itself.html