1526104 Tom devoted his life to the study of this phenomenon. Spamster 1 1777513 It's a normal phenomenon. Spamster 281038 A rainbow is a natural phenomenon. CK 245182 Acid rain is not a natural phenomenon. CM 1847635 This phenomenon is very easy to explain. al_ex_an_der 67427 In Alaska you can see natural phenomena like the aurora, right? CK 1332009 Three out of four Americans believe in the existence of paranormal phenomena. Spamster