It was Scientific American. When I was an unemployed pre-internet late-teen, I went through my local library's entire collection, right back to the first Mathem

It was Scientific American. When I was an unemployed pre-internet late-teen, I went through my local library's entire collection, right back to the first Mathematical Games column, and photocopied everything I found interesting. That was one of the articles I snagged. I did successfully make some iridescent chocolate after that, with a diffraction grating I bought from Edmunds Scientific as a mould. By the by, you may be interested in this: https://www.litiholo.com/ https://www.litiholo.com/ I'm probably going to buy one at some point.