The scope room dustiness post reminded me of the hilarious story of the first report of second harmonic generation of a laser. The authors presented a photographic plate that showed the exposure the main laser beam, as well as a “small but dense” spot from the doubled beam,
See the spot? You won’t. Because the editor removed the spot, thinking it was a speck of dust on the plate. Ha!
When I first heard this story, I didn’t believe it. I assumed it was a contrast issue when the paper was scanned into a PDF. So I went to the library and found the original print version. No spot there, either!
That really made my day.