Column editor's note: Similar experiments using plastic have been done. See Matt Lowry, “Colorful conundrum,” Phys. Teach. 44, 274 (Oct. 2006).
While doing a search for ways to use a new “blue” laser pointer, I came across a blog by Rhett Allain, who is an associate professor of physics at Southeastern Louisiana University. In the article he mentions how olive oil fluoresces red when illuminated by a green laser pointer. Of course I had to see this for myself, so I went to the salad dressing shelves at my local grocer to get a bottle of olive oil, a product about which I know next to nothing. When I tried sending green laser light through the oil, I observed not red but yellow fluorescence—not very exciting, but certainly interesting. In Fig. 1 the laser beam is made visible in air using scattering by “canned haze.”1 But in the...
