The Equations of Light

Today's Scripture

Psalm 111:2 — "Great are the works of the LORD, studied by all who delight in them."

Genesis 1:3 — "And God said, 'Let there be light,' and there was light."

John 1:1-3 — "In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through him, and without him was not any thing made that was made."

The Big Idea

James Clerk Maxwell discovered that electricity, magnetism, and light are one thing — a set of four equations that physicists rank with anything Newton or Einstein ever did. He was also a Bible-saturated Presbyterian who wrote out his own prayers by hand and put a psalm over the door of his laboratory. For Maxwell, the deepest physics and the deepest faith pointed the same direction: toward a God who made light, loves order, and wants to be known.

Reflection

"What's the go o' that?"

James Clerk Maxwell was born in Edinburgh, Scotland, in 1831 and grew up on a country estate called Glenlair. He was the kind of child who exhausts adults with one question, asked about everything: "What's the go o' that?" — Scots for how does that work? When the answer was vague, he pressed: "But what's the particular go of it?" His mother taught him his lessons and his Bible; he could recite long stretches of Scripture from memory as a boy. She died of cancer when he was eight — the same disease that would one day take him, at almost the same age.

The grief did not curdle him. He grew into a man his friends described as playful, generous, and deeply devout — an evangelical Presbyterian who led daily prayers for his household and knew the Psalms nearly by heart. And the boy's question never went away; it just acquired mathematics. At Cambridge, then in professorships at Aberdeen and London, Maxwell asked "what's the go o' that?" about Saturn's rings (he proved they must be made of countless small particles — confirmed by spacecraft a century later), about gases, about color vision. He produced the world's first color photograph. Any one of these would have earned him a place in the textbooks.

Behind it all was a conviction the Bible plants on its first page: the world is spoken, not random. Genesis 1:3 — "And God said, 'Let there be light,' and there was light." A spoken world is an intelligible world — a world with a grammar. Maxwell hunted grammar for a living. John Calvin had named the payoff three centuries earlier:

"The skillful ordering of the universe is for us a sort of mirror in which we can contemplate God, who is otherwise invisible." — John Calvin, Institutes of the Christian Religion

Let there be light, in four lines

Maxwell's masterpiece came in the 1860s and 70s. Faraday — yesterday's bookbinder — had discovered the phenomena of electricity and magnetism and imagined invisible fields, but he lacked the mathematics to formalize them. Maxwell supplied it. In a handful of compact equations, he united electricity and magnetism into a single thing: the electromagnetic field. Then came the thunderclap. His equations predicted waves rippling through that field — and when he calculated their speed, out came the speed of light. Light itself, Maxwell realized, is an electromagnetic wave. Color, sunshine, the glow of a screen: all of it, electricity and magnetism dancing.

It is one of the greatest unifications in the history of thought, and it opened the door to radio, radar, television, and the phone in your pocket. Einstein kept a portrait of Maxwell on his study wall, alongside Faraday and Newton, and said his own relativity rested on Maxwell's foundations. Physicists still rank "Maxwell's equations" among the most beautiful things humans have ever written.

A man who spends his days inside the mathematics of light might be expected to think light needs no Author. Maxwell concluded the opposite. He once remarked, after long reading in philosophy:

"I have looked into most philosophical systems, and I have seen that none will work without a God." — James Clerk Maxwell, quoted in Lewis Campbell's Life

Scripture had already woven light and Word together. Psalm 104:1-2 — "O LORD my God, you are very great!... covering yourself with light as with a garment, stretching out the heavens like a tent." And John's Gospel gathers it all up in Christ: John 1:1-5 — "In the beginning was the Word... All things were made through him... In him was life, and the life was the light of men. The light shines in the darkness, and the darkness has not overcome it." The Word who spoke "let there be light" is the true light, John 1:9 — "The true light, which gives light to everyone, was coming into the world." Maxwell's equations describe how light moves. John tells you where it comes from, and where it was headed: toward us.

C.S. Lewis pointed out that even our ability to recognize darkness testifies to light:

"If the whole universe has no meaning, we should never have found out that it has no meaning: just as, if there were no light in the universe and therefore no creatures with eyes, we should never know it was dark. Dark would be without meaning." — C.S. Lewis, Mere Christianity

The psalm over the door

In 1871 Cambridge called Maxwell back to build something new: the Cavendish Laboratory, which under his founding directorship — and after it — became one of the most important rooms in scientific history. (Electrons and the structure of DNA were both discovered by Cavendish men.) Under Maxwell's directorship, a Latin inscription was carved over its great oak doors. It was Psalm 111:2: "Great are the works of the LORD, studied by all who delight in them."

Stop and take that in. Over the entrance to one of the temples of modern physics, a psalm — chosen in the era of Maxwell, the believing director. Generations of physicists have walked under it on their way to their instruments. The verse is almost a job description: God's works are great; therefore they repay study; and the students who get the most from them are the ones who delight. Delight is not unscientific. According to Psalm 111, it is the correct laboratory attitude.

We know what Maxwell's delight looked like in private, because his handwritten prayers survived among his papers. One begins:

"Almighty God, who hast created man in Thine own image, and made him a living soul that he might seek after Thee and have dominion over Thy creatures, teach us to study the works of Thy hands, that we may subdue the earth to our use, and strengthen the reason for Thy service." — James Clerk Maxwell, handwritten prayer

Notice the theology packed in there: made in God's image, made to seek God, given dominion, taught by God to study God's works, reason strengthened for service. That is Genesis 1, Psalm 8, and Psalm 111 fused into a working scientist's morning prayer. J.I. Packer would later put the same creed in catechism form:

"What were we made for? To know God. What aim should we set ourselves in life? To know God. What is the 'eternal life' that Jesus gives? Knowledge of God." — J.I. Packer, Knowing God

Maxwell studied the works because he loved the Workman. Every good thing on the lab bench was, for him, a delivery from above — James 1:17 — "Every good gift and every perfect gift is from above, coming down from the Father of lights, with whom there is no variation or shadow due to change." Father of lights: Maxwell of all people knew how fitting that name is.

And the faith was never only cerebral. As laird of Glenlair, the world's greatest living physicist walked the lanes of his Scottish parish visiting sick and elderly neighbors, reading Scripture and praying at their bedsides. His biographer — his lifelong friend Lewis Campbell — recorded it because it was simply who Maxwell was: the same man at a cottage bedside and a Cambridge lectern, serving the same Lord at both.

The Light no equation captures

In 1879, at just forty-eight, Maxwell was dying of the same abdominal cancer that had killed his mother. Those who attended him recorded his calm. He quietly cared for his ill wife, Katherine, from his own sickbed as long as he could. Near the end he told a colleague:

"The only desire which I can have is like David to serve my own generation by the will of God, and then fall asleep." — James Clerk Maxwell, during his final illness

He is echoing Acts 13:36 — David "served the purpose of God in his own generation and fell asleep." That is how a man dies when he has settled, long before, what his equations were for.

Here is the gospel center of Maxwell's story. The Bible says 1 John 1:5 — "God is light, and in him is no darkness at all" — and then dares to say that this light has a human face. Hebrews 1:3 — Christ "is the radiance of the glory of God and the exact imprint of his nature, and he upholds the universe by the word of his power. After making purification for sins, he sat down at the right hand of the Majesty on high." Read that as a physicist for a second: the universe is upheld, moment by moment, by the Word — the same Word who went to a cross to make purification for sins. The light Maxwell measured at 300,000 kilometers per second is a creature. Its Maker let himself be plunged into our darkness so that we could walk in his light. Augustine described what happens when that Light stops being a doctrine and arrives in person:

"You called, you shouted, and you broke through my deafness. You flashed, you shone, and you dispelled my blindness." — Augustine, Confessions

Maxwell heard that call early and never stopped answering it — in equations, in carved psalms, in handwritten prayers, and finally in a quiet falling asleep, like David, when his generation had been served.

Going Deeper

Adopt Psalm 111:2 as your "door verse" this week. Write it on a sticky note and put it where you start your work — laptop lid, locker, dashboard, kitchen sink. Each time you see it, take five seconds for two questions: Whose works am I about to handle? and Where is the delight in this? You are not a machine doing tasks. You are an image-bearer studying, arranging, and serving the works of the LORD.