0.13% is enough to mislead the eye: Earth's water is a volumetric sliver, yet it forms a skin across roughly 71 percent of the surface, so an observer sees coverage, not the planet's deep rock and metal inventory. Surface area wins here. From orbit, the visible hemisphere is judged by its outermost layer, not by a planetary balance sheet.Blue is no mere paint. Liquid water absorbs longer red wavel...More