The Great Plague has arrived in Cambridge. The university has closed. You are sent home to your mother's farm at Woolsthorpe — a manor in Lincolnshire, a small stone house, an apple orchard, fields. You are 22. You have no laboratory, no colleagues, no supervisor, no deadlines.
You have notebooks, a prism, some lenses, and an almost frightening ability to concentrate on a problem until it breaks. You will spend 18 months here, largely alone.
In those 18 months, you will: invent the mathematics of calculus (you call it "the method of fluxions"). Derive the law of universal gravitation from first principles after watching an apple fall in the orchard. Discover that white light is not pure but is composed of all colors of the spectrum. Begin the foundations of what will become the Principia Mathematica.
You write almost none of this down in publishable form. You fill private notebooks in a cramped hand. When Cambridge reopens, you will return and tell almost no one what you have done.
Newton sat on his discoveries for years. He shared calculus with almost no one. He told virtually no one about the gravity work. He returned to Cambridge, became a Fellow, was appointed Lucasian Professor of Mathematics at 26, and continued working privately. His reluctance to publish came from a deep, almost paranoid fear of criticism and priority disputes. It was not false modesty — he genuinely could not bear the thought of someone attacking his ideas before he considered them finished. He would eventually be forced to publish by the persistence of Edmund Halley (of Halley's Comet), who essentially commissioned the Principia and paid for its printing himself in 1687, twenty years after the plague year.
You have published your first major scientific paper — a letter to the Royal Society describing your experiments with prisms and the nature of light. You have shown, conclusively, that white light is not pure but is a mixture of all colors, each of which refracts at a different angle. This is not what anyone believed. The established theory, held by Robert Hooke and others, was that colors were modifications of white light — additions or distortions. You have shown they are components.
Hooke has written a dismissive response. He says your experiments are nothing new and your conclusions are unproven. You have been waiting for this — the public criticism you feared. Your response is devastating: precise, logical, contemptuous. But the argument is now public. Other critics pile on. You find the experience intolerable.
You mean it. You want to withdraw from public science entirely.
Newton largely withdrew from publication after the optics dispute. He spent the next several years working almost entirely in private, going deeper into alchemy, theology, and mathematics. He did not publish another major work for 15 years. His feud with Hooke was never resolved — when Hooke died in 1703, Newton became President of the Royal Society and some historians believe he systematically erased Hooke from the historical record: there is no authenticated portrait of Hooke in existence, and several contemporaries noted that materials relating to Hooke disappeared during Newton's presidency.
If I have seen further, it is by standing on the shoulders of giants.
Edmund Halley — astronomer, future predictor of the comet that bears his name — comes to visit you at Cambridge. He asks you a question that has been puzzling him and his colleagues: what shape would the orbit of a planet be if the force of attraction toward the sun decreased with the square of the distance?
You answer immediately: an ellipse. Halley asks how you know. You say you calculated it years ago. He asks to see the calculation. You tell him you cannot find the paper. You will redo it and send it to him.
What you send him three months later is not just the calculation. It is the beginning of what will become the Principia Mathematica — a unified mathematical description of the physical universe. Halley reads it and understands immediately that this is the most important scientific document ever produced. He travels back to Cambridge and begs you to let him publish it.
You have been sitting on the foundational ideas for 20 years. Hooke now claims that the inverse-square law was his idea and you have stolen it. You are furious.
Newton published the Principia in 1687, with Halley paying the printing costs personally. He removed all acknowledgments of Hooke from the manuscript — not one mention of Hooke remained in the final version, despite references that had existed in early drafts. The Principia described the laws of motion, universal gravitation, the orbits of planets and comets, tidal theory, and the speed of sound. It was immediately recognized as revolutionary. Leibniz, who had independently invented calculus, said it was the work of the greatest mind that ever lived. It was dedicated to the Royal Society. Hooke received no credit and died bitter six years before Newton — who reportedly became notably more sociable immediately after Hooke's death in 1703.
You have written more words about alchemy than about physics. Your alchemical notebooks — which you kept strictly secret your entire life, because alchemy was technically illegal in England — contain over a million words. You have built a furnace in your garden and conducted experiments for decades. You are looking for the Philosopher's Stone. You believe it is possible to transmute base metals into gold.
You are also writing extensively about biblical prophecy. You believe the Book of Daniel and the Book of Revelation contain encoded predictions about history and the future. You have dated the end of the world — your estimate, based on detailed calculations from scripture, is not before 2060.
Your theological writings are even more secret than your alchemical ones: you have concluded, after 30 years of study, that the doctrine of the Trinity is a fraud introduced into Christianity in the 4th century. You believe Jesus was not God. This is heresy. If published, it would cost you everything — your Cambridge fellowship requires you to be ordained in the Church of England, which you have repeatedly avoided and been given special exceptions from.
A colleague discovers your alchemical notebooks. He asks what you are doing.
Newton continued both. He never published his alchemical or theological work in his lifetime. After his death, John Maynard Keynes bought a trunk of Newton's alchemical papers at auction and read them. Keynes then wrote his famous essay: "Newton was not the first of the age of reason. He was the last of the magicians." Modern scientists have found something stranger: Newton's alchemical experiments, while they never produced gold, did include careful observations about chemical processes that anticipate modern chemistry. He may have been one of the last people to attempt to unify the physical and the spiritual into a single system. He was also, very likely, slowly poisoning himself with mercury from his furnace experiments — which may explain the mental breakdown that followed in 1693.
Something has gone very wrong. You have been writing letters to friends — Samuel Pepys, John Locke — that are incoherent, accusatory, paranoid. You accuse Locke of trying to "embroil" you with women. You tell Pepys you have neither ate nor slept well for a twelvemonth. Your mental state has collapsed in a way that frightens everyone who knows you.
Historians have debated what happened. Mercury poisoning from your alchemy experiments is one theory — examination of your hair centuries later found mercury levels 40 times higher than normal. A nervous breakdown from overwork and social isolation is another. A profound loneliness, possibly following the end of a close friendship, is a third.
You recover over the following year. But you never return to serious original scientific work. The greatest mind in science — at age 50, with possibly decades of productive life ahead — essentially stops doing science.
Newton accepted the appointment as Warden of the Royal Mint in 1696, moving to London. He took the job with the same obsessive intensity he had brought to physics. England's currency was in crisis — coins were being clipped and counterfeited at a rate that threatened the economy. Newton reorganized the mint, prosecuted counterfeiters with a ferocity that sent 28 people to the gallows, and oversaw the Great Recoinage that replaced all of England's clipped coins. He became Master of the Mint in 1699, a position he held for life. He was extraordinarily good at it. He never returned to original scientific research.
You have been methodically hunting counterfeiters. England's currency counterfeiting problem is severe, and you have brought to it the same systematic approach you brought to physics. You have built a network of informants. You attend executions. You have personally interrogated suspects in taverns, prisons, and brothels, sometimes in disguise. You are, in some senses, running a detective operation.
The most skilled counterfeiter in England is William Chaloner — a charming, brilliant con man who has fooled the Mint before and who has publicly claimed that he, not Newton, knows how to reform the currency. He has accused Newton of corruption. He has friends in Parliament.
You have spent three years building a case against Chaloner. You now have it. He will hang.
Newton pursued Chaloner with a ferocity that went beyond professional duty. He personally wrote the brief against him, gathered evidence across multiple jurisdictions, and ensured there was no escape from the charge. Chaloner was convicted, hanged, and drawn and quartered at Tyburn in 1699. Newton attended to make sure it was carried out. He sent 28 people to their deaths during his time at the Mint. His biographer Richard Westfall wrote that Newton "brought to the persecution of counterfeiters the same avenging wrath he directed at anyone who questioned his priority or his character." He was, in this as in science, absolutely unforgiving.
Gottfried Wilhelm Leibniz, the German mathematician, invented calculus independently of you — probably around 1675, after you had already done so in 1666 but before you published anything. His notation (which we still use today: dy/dx, the integral sign) is actually superior to yours. He published first.
You have been at war with Leibniz over the priority of calculus for a decade. The dispute has consumed European mathematics. Now, as President of the Royal Society, you have appointed a committee to investigate the priority question.
You have also secretly written the committee's final report yourself, while nominally letting the committee produce it independently. The report concludes that you invented calculus first and that Leibniz is a plagiarist. The report does not mention that you wrote it.
Newton wrote the report himself and published it under the committee's name. Leibniz died in 1716, partially broken by the dispute and largely ignored by his own patron, the Elector of Hanover, who had just become King George I of England — Newton's territory. Newton reportedly said, of defeating Leibniz: "I broke his heart." The modern historical consensus is that both men invented calculus independently, that Leibniz's notation was better, and that Newton's behavior in the priority dispute was one of the ugliest episodes in the history of science. Newton was right about the priority question. He was completely wrong in how he pursued it.
You are 83, one year before your death. You are still sharp. You are still working on revisions to the Principia and your optical work. You have never married. You have, as far as anyone knows, never had a romantic relationship. You have lived in your own mind for more than 80 years.
A young antiquarian named William Stukeley visits you and records what you say. You tell him the story of the apple — watching one fall in the orchard at Woolsthorpe during the plague year, which led you to wonder why apples always fall perpendicularly to the ground. "Why should it not go sideways, or upwards? Assuredly, the reason is that the Earth draws it."
This is not quite the story of a sudden revelation — you developed gravity over years of calculation. But the apple is true, and the moment of wondering is true. At 83, sitting with Stukeley, you are the most famous scientist who has ever lived. The Principia has remade the world. Your portrait hangs in institutions across Europe.
Stukeley asks what you consider your greatest achievement.
Newton told Stukeley: "I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me." He died on March 31, 1727. He was given a state funeral at Westminster Abbey — the first scientist ever so honored. His pallbearers included dukes and earls. Voltaire attended. 7,000 pages of unpublished alchemical and theological manuscripts went into a trunk that Keynes eventually bought at auction in 1936. The ocean of truth remained, as Newton said, largely undiscovered. It still does.