The colors blue and red are used in the U.S. to represent political left and right, which at the extremes might be said to run from communism to fascism., Yet even that’s a tiny slice of the whole. (Image by Philip Ronan, Gringer; Wikimedia Commons)We are accustomed to a left–right political spectrum. But said spectrum is only a tiny corner of the whole space of possibilities, even though practically everyone you know is wedged into it. Similarly, we use the word “light” to implicitly...
