This chemical is a fluorophore, containing many aromatic groups and having the ability to absorb light and re-emit a new photon (fluorescence). There are other types of fluorescence that allow re-emission of light at higher energies or even the same energy but in this case the re-emitted light is at a lower energy. Because it is under a UV light, it absorbs the UV and the light that it re-emits will be visible to human eyes. Sadly, what we can see is only a very narrow band of the spectrum, still pretty awesome!
The Original Broadway Cast of Disney’s The Lion King
Mufasa :: Sarabi :: Young Nala and Simba :: Simba :: Nala:: Rafiki :: Pumba and Timon :: Zazu :: Scar :: The Hyenas (Ed, Shenzi, and Banzai)
This was one of the most amazingly costumed Broadway shows I’ve ever seen.