There’s a passage in John Milton’s Paradise Lost that’s always haunted me. It’s near the end of Book II, when Satan makes his journey from the depths of Hell to inspect Earth. It’s a strenuous climb through unimaginable stretches of grim darkness, in the direction of those gleaming heights he once called home. In his fatal longing to reign supreme, he has chosen for himself the abandoned wasteland of disorder which he supposes to be beyond the regions of Heaven’s influence. But he wants more. And so he makes his way to the advancing outskirts of God’s kingdom, to peer into the new creation called Eden and plan his attack.
His journey takes him through the realm of Chaos, now retreating as God’s imperium gives shape and form to the domain He has prepared for Man. As he passes the borderland of formless disarray, he touches finally on the first fringes of the cosmos where earth is nestled like a jewel:
But now at last the sacred influence
Of light appears, and from the walls of Heaven
Shoots far into the bosom of dim Night
A glimmering dawn.
Milton was a master of more languages than one—he had steeped himself in Greek and Latin since his boyhood, and his grasp of English reached down beneath its surface to the rich soil where its ancient roots could be felt. You can see him digging beneath the topsoil in the way he uses the word “influence” here: in-fluo in Latin means “to flow in,” and so the concept for Milton is no mere abstraction. This is physical influence, a dead metaphor brought back to life. The radiance of Heaven streams like a golden river from its fountainhead to this farthest outpost of divine territory. Space itself feels lighter, less dense, so that “Satan with less toil, and now with ease / Wafts on the calmer wave by dubious light[.]”
The poem first appeared in 1667. In two decades, Isaac Newton would publish his Principia Mathematica, which would lay forth the rules of motion for all physical bodies both on earth and in the heavens. Newton’s staggering achievement was to shatter an ancient barrier between the “sublunary” realm and the “superlunary” region beyond the moon, where different rules were thought to apply. Newton’s laws appeared to govern everything from the core of the earth to the farthest reaches of space, making of the cosmos a seamless expanse where all bodies, large and small, could be counted on to follow the same logic.
Years later, in 1704, Newton would produce his Opticks, a “corpuscular” account of light which described it as a stream of small masses—so that light, too, might become a kind of matter in motion. Before that, René Descartes had imagined light as a wave of movement shuddering through particles of air which “all touch and press one another as much as possible,” so that their contact would pass the ray from one region to the next in an unbroken chain. It would be more than a century before James Clerk Maxwell could fully describe light as an electromagnetic wave, two complementary forces cresting together along perpendicular planes through space. Even then, scientists would search in vain for some physical medium that could communicate those forces, some “ether” whose subtle fluid was undulating as light flickered through the air.
It was Einstein who argued persuasively that the forces themselves were the medium, as Michael Faraday before him had guessed. The general theory of relativity aimed to replace the ether with a field of energy, so that “only field-energy would be left, and the particle would be merely an area of special density of field-energy.” The fabric of this energy field was the cradle of existence, and its waves were the waves of light.
But there had always been an ancient theory, echoed among the Medieval Arabic philosophers who helped set optics on its scientific footing, that physical light was merely an extension of some yet more dazzling sun, a light whose brilliance had formed the world itself. This light of God was the glow that made all things possible. The throb of its energy sustained the world.
And there was Milton, with the poet’s feel for the heartbeat of words, a blind man feeling his way to the unseen light at the heart of things. Creation comes riding on the billows that roll outward from the walls of heaven, a light whose influence is felt before it can be seen. “And fast by, hanging in a golden chain / This pendent world, in bigness as a star” would feel the warmth and radiance of a physical glow that expressed, in the language of matter, a spiritual vitality that had laid the foundation stone of time. “Let there be light—and there was light”: could it be that the poet spoke more truly than he knew?
Rejoice evermore,
Spencer