by Elio — I just love it when two fas­ci­nat­ing top­ics cross paths. Two that I have in mind now are bi­o­lu­mi­nes­cence and pho­tore­ac­ti­va­tion. Bi­o­lu­mi­nes­cence is an old phe­nom­e­non, first rec­og­nized when hu­mans first en­coun­tered fire­flies...