A sky without blue, is like a man without air. it does not exist.

why is it that a sky without blue does not exist? it just is that way. Life is amazing and with so many gifts and so many unanswered questions, our mind will never be at ease. A man without air doesn't exist for a man needs oxygen to breath. They will drop dead within 5 minutes of not breathing. but hence, in space they have no real air they choose to live off of an oxygen supply. so is it air we need or oxygen? it is clearly oxygen. but if you were to tell man one day you don't need to breath! so stop breathing immediatly, they would still continue to breath. it is instinct, it is a stress reliever. We need to breath and the sky needs to be blue. If the sky were red, man-kind would surely go insane.