Originally Posted By: Faldage
Just to throw another complication in, noctilucent clouds are no brighter than dialucent clouds; they just seem so since they have less competition from the sky.

Not really a complication, because it's true of anything that shines, anyway. Stars shine during the day, but we cannot perceive them. If lightning bugs did light up in the day, we would not notice.

 Originally Posted By: BranShea
But a wonderful thing to have at an after sunset swim. 'Sea lightning'.

Have you done that, Bran? Swimming with bioluminescents would be so cool!