Maxwell's Equations, Written by a Man of Prayer

The lamps in that basement room at King's College never gave enough light, not for close work, and I remember blowing on my fingers between drafts because the cold came up through the stone floor no matter how many coals we fed the grate. I copied for him three winters running. Fair copies, mostly — pages of his slanted hand turned into something a printer could set without cursing. I knew the loops of his letters better than I knew my own signature by the end of it.

He worked the way a man works who has already seen the shape of the thing and is only waiting for his pen to catch up. Coils on the bench, a galvanometer with its needle trembling, and Mr. Maxwell bent over it all with his sleeves rolled and his spectacles pushed up on his forehead, muttering to himself in that soft Galloway voice that never quite lost its border burr no matter how many years of London and Cambridge tried to sand it down. He would write for an hour without lifting his eyes. Then he would stop, set the pen down flat across the inkwell's lip, and go still for a moment before starting again. I did not understand, at first, what that stillness was.

Before that winter, the world kept electricity and magnetism and light in three separate rooms, so to speak. Men who studied one rarely trespassed on the others. Mr. Newton's universe of hard little points pushing and pulling across empty space had held for a hundred and fifty years, and it held well enough for planets. But Mr. Faraday, over at the Royal Institution, had spent decades insisting that the space itself was doing something — that there were lines of force running through the air between a magnet and a wire, real as rope, though no one could weigh them or touch them. Most of the mathematical men treated this as poetry. Beautiful, maybe. Not physics.

Mr. Maxwell did not treat it as poetry. He set himself the task of putting Faraday's lines of force into the language of equations, and that meant building a mathematics for something nobody could see. Night after night I watched him wrestle notation into shapes it did not want to hold, crossing out whole sheets, muttering that the symbols were fighting him. Once he told me, not looking up from the page, that a man who tries to write down what the aether is doing had better be humble about it, because the aether does not consult him first.

By December of 1864 the paper had a shape he trusted enough to read aloud. I carried the folder to the Royal Society myself, tied with tape gone soft from handling, and I sat at the back of the room while he stood and read it to men who had known him since he was a boy prodigy at Edinburgh Academy answering questions about ovals that grown mathematicians could not answer. He read in that same unhurried voice. No flourish in it. Just a man walking his listeners, step by careful step, through equations that described how a current in one wire could tug at a current in another across empty space, and how that tug propagated — not instantly, but at a speed, like a ripple crossing a pond.

That speed was the part that stopped my breath, copying it out afterward. He had built the electromagnetic field as a thing with its own dynamics, its own energy stored in space itself rather than in the wires and magnets that seemed to cause it. And when he worked through what a disturbance in that field would do — how fast it would travel — the number that came out of his equations matched, near enough to make a man's hand shake, the measured speed of light. Light, he wrote, was nothing more nor less than a wave in this same electromagnetic field. Two sciences that had never spoken to each other in three thousand years of study turned out to be one science wearing two coats.

He was careful with the number. I remember him checking it twice, comparing it against the best measurements of the day, the ones from optics, and finding the agreement close enough that he allowed himself, in that dry way of his, to call it more than a coincidence. Not to shout it. He was not a man who shouted anything. But there was a kind of settled satisfaction in him for days afterward, the satisfaction of a man who has been climbing in fog and suddenly feels solid ground where he expected another ledge.

It was in the margins of those same working notes, the scraps I copied from before the fair draft, that I first saw the other side of him. Small lines, tucked between a derivation and a crossed-out attempt at the next. Not equations. Words. A plea, brief and plain, for steadiness in the work, for the mind to be kept honest, for the labor to serve some purpose beyond his own name. I did not speak of it to him. It did not seem a thing a copying clerk was meant to remark upon, a man's prayers caught sitting beside his mathematics like two lodgers who had agreed to share a room without complaint.

I asked myself, more than once, sorting those sheets by lamplight, what kind of man prays in the same hand he uses to calculate the velocity of light. I came to think there was no contradiction in it for him at all. He treated the universe as a made thing, ordered by a mind, and he seemed to feel that finding its order was itself a kind of listening. He was not hunting for God in the gaps where equations ran out. He found nothing strange in kneeling and calculating in the same evening, as if both were forms of the same attention.