“The Pale Blue Dot was the latest in a long history of association of the color blue with our home in the universe, and with life itself. Two decades before Voyager, as Apollo 8 circled the moon, astronauts recorded the now-famous “Earthrise”—a stunning color photograph of a bright blue-white hemisphere suspended above a gray lunar landscape. Four years later, the Apollo 17 mission captured a beguiling whole-Earth image that became “The Blue Marble.””
“These space-age portraits drive home the fact that we evolved on a blue planet. Some people, like Wallace Nichols, the scientist and author of Blue Mind, have suggested that we have a primal, near irrational, desire for water and its blue oceans and lakes. This thesis is supported by a recent global survey suggesting that blue is our favorite color. In the United Kingdom alone, a world-beating 33 percent of respondents ranked blue above anything else, with red a runner-up at about 15 percent.”
“Blue has made it into our flags and emblems, too. NASA, the European Space Agency (ESA), the Search for Extraterrestrial Intelligence (SETI), and the Planetary Society are represented by blue backdrops, or abstract blue Earths, or blue symbols. The One Flag in Space initiative advocates a Blue Marble flag, in which a photo of the Earth is shown on a blue backdrop. Just this May, a Swedish design student named Oskar Pernefeldt proposed an International Flag of the Planet Earth that has attracted wide media coverage, consisting of seven interlocking circles on a vivid blue background.”
“The truth is that colors are a cosmically parochial idea. The electromagnetic spectrum is not inherently divisible into neat pieces, except by limited sensory facilities. Light at different wavelengths is entwined with a vast array of physical processes, from the probabilistic hop and skip of electrons between atomic energy levels, to scattering and diffraction by matter’s electromagnetic fields. Wildly disparate processes can produce or consume photons of identical energy, generating almost indistinguishable gross features such as color. And sometimes a single underlying physical process can make utterly dissimilar objects appear the same.”