Fluorescein
This chemical is aĀ fluorophore,Ā containing many aromatic groups and having the ability toĀ absorb light and re-emit a new photon (fluorescence).Ā There are other types ofĀ fluorescenceĀ that allow re-emissionĀ of light at higher energies or even the same energy but in this case theĀ re-emittedĀ 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!













