“Why the Sky and Ocean are Blue” by Rebecca Solnit
Completion requirements
"The world is blue at its edges and in its depths. This blue is the light that got lost. Light at the blue end of the spectrum does not travel the whole distance from the sun to us. It disperses among the molecules of the air, it scatters in water."
Click https://www.brainpickings.org/2014/08/20/rebecca-solnit-blue/ link to open resource.