The Speed of Light: Constancy and Cosmos

6. Internal Relations

61 T. S. Eliot once wrote of “a music heard so deeply that it is not heard at all.”1 I am saying something similar about light. Light, I believe, is so deeply informative of our nature that we cannot bring it forward in a detached, informational way. Expressed differently, as the very coin of illumination and understanding, light cannot be traded against itself. Hence, we will never overtake it as something apart from us. That would be like overtaking the horizon or flying skyward to get a closer look at a rainbow. Because horizons and rainbows do not precede visual experience, they cannot be detached therefrom and explained as freestanding phenomena, and so complete explanations always reference observers. In a more fundamental sense, the same is true of light. Any earnest explanation of light must always reference observers. This is because light, while informative of the world, is simultaneously informative or constitutive of our own Relational Light Inasmuch as God sprinkled His light upon humanity, human beings are essentially one. In reality, His light never separated. Jalal Al-Din Rumi, Rumi: A Spiritual Treasury 62 · The Speed of Light nature. Going both directions at once, light informs or shapes our knowing faculties while informing us of the world. Twenty-five centuries ago Heraclitus seems to have grasped this point. For him logos was the primal cosmic principle, manifesting itself as “the brilliant fiery stuff which fills the shining sky and surrounds the world.”2 He let the manifest brilliance of the world command his thinking and concluded that the shining of nature is the showing of truth. Or, to put the matter more simply, for truth to be shown, it must be shone: truth implies brilliance. Furthermore, Heraclitus (much like Plato after him) argued that human understanding arises from the consonance that exists between the outer logos (“world-fire”) and one’s inner logos (“soul-fire”).3 Philosophy or the pursuit of wisdom could never be the result of mere curiosity, for curiosity would be impossible if there were no preexisting harmony or isomorphism between mind and world. That harmony enables understanding by providing the mind with targetable phenomena; the lines of harmony, as it were, undo the mind’s self-containment. Better said, they never really let that self-containment occur in the first place. What Heraclitus wanted to know was how understanding of the world is possible in the first place? What sparks the wondering, thinking, knowing process? For him that spark was not hard to find: it was all about him, the fire-illuminated world, or the world made intelligible by fire. The match that struck the world into fiery existence simultaneously struck a fire in his own mind. Logos was thus the first place or thing, the primal principle of intelligence or light that grounds and enables human understanding. Read this way, Heraclitus collapses the distinction between mind and world that so deeply shapes modern thought. Still, the skeptic is inclined to ask what makes light so extraordinary? Why single it out as if it were unique? This is a fair question and one very much in the spirit of modern science, which since the seventeenth century has broken down Aristotelian distinctions between the earth and the starry heavens (the sublunar and supralunar spheres). With this success, the universe has become homogenous, a system thoroughly knit together by common laws and substances. (No longer does one approach the utterly transcendent reality of God, as Dante did in his Divine Comedy, by voyaging toward the stars.) The outstanding Relational Light · 63 exception to this rule of commonality, however, is mind. Modern science has traded on the Cartesian assumption that mind is not knit into the cosmic system; observers consequently can view reality without participating in it. So another fair question, it seems to me, is what makes mind so special? In what follows I propose that light, while extraordinary, is also deeply ordinary owing to its relationality. Einstein suggested that light, while possessing a finite velocity, “plays the role, physically, of an infinitely great velocity” by virtue of its constant measured speed.4 That speed, I have argued, specifies a universal relation between observer and things observed. The eye sees things, but only as light brings the two into relation, and the objects seen—their spacetime properties—fluctuate so as to preserve the constancy of the speed of light. This relationality goes all the...