I’m Toni Mount, historian and author of popular history/science books. The World of Isaac Newton is my fifth book for Amberley Publishing. I’ve always been intrigued by the way big events in history affected everyday life, or sometimes, hardly caused a ripple.

Isaac Newton by Sir Godfrey Kneller. Institute for Mathematical Sciences, University of Cambridge. (Wiki Commons, The World of Isaac Newton, Amberley Publishing)

Isaac Newton lived through some tumultuous times – civil war, plague, religious upheaval – and I wanted to discover how these things influenced Newton’s life and ways of thinking. He was quite outstanding but some of his acquaintances were equally inspirational and interacted with Newton, whether supporting or sometimes opposing his ideas. Sir Christopher Wren, Robert Boyle, Samuel Pepys, and Edmund Halley were just a few of the most famous; Robert Hooke, Gottfried Leibniz and John Flamsteed less well known, partly due to their disputes with Newton. The World of Isaac Newton is a tapestry of social history, science, politics, and religious theory, all woven together to set Newton in the context of his times and to show how his influence continues, still affecting our lives today.

Isaac Newton may have died almost 300 years ago, in 1727, but his legacy lives on in the twenty-first century. If Newton had not begun to explore and explain the rainbow and inspired others to extend his discoveries, laser surgical techniques might still belong to the realm of science fiction instead of removing brain tumours, correcting eyesight, and steadying the tremors of Parkinson’s sufferers. Your mobile phone and microwave only work because of what exists beyond Newton’s visible spectrum of colours. From TV broadcasting to x-raying broken bones, from removing unsightly birthmarks to finding black holes, we have Newton to thank for setting scientists on the path to discovering such incredible things.

The apple tree at Woolsthorpe Manor, Colsterworth, Lincolnshire. (GM, The World of Isaac Newton, Amberley Publishing)

Isaac Newton invented calculus and – love it or loathe it – this form of maths is vital today. Unlike Newton, we have computers to work out the equations, but calculus can determine such things as the trajectory for a landing on Mars or the most efficient route for a delivery driver making multiple stops or even the best design for a new bridge. Newton’s calculus is also used in Artificial Intelligence so a robot can ‘learn’ how to respond to certain situations, whether vacuuming the living room around the furniture, dimming the lights, or playing your favourite music tracks when you tell it to.  

Newton also invented the type of coins we spend today. Before Newton became Warden of the Royal Mint at the Tower of London, our coins were of virtually pure silver or gold. It was relatively easy for unscrupulous ‘coiners’ to trim the edges of the soft metals, reducing their value and using the trimmings to melt down and cast counterfeit coins. Newton’s knowledge of chemistry and metallurgy was vital when he re-called and re-minted all the coins in the realm. He added a dash of copper to the silver to make the metal much harder and more difficult to trim. He also invented a way to make a pattern – known as ‘milling’ – around the outside of the coin, so it could be seen at a glance if it had been trimmed. How to put the milling round the edge remained Newton’s secret for some while and counterfeiters had a hard time faking it. So, Newton revitalised our monetary system and made sure coins were worth their true value. The new harder alloy meant coins didn’t wear down in circulation so quickly.

Newton’s Note Book. (Courtesy of Trinity College Library Cambridge, The World of Isaac Newton, Amberley Publishing)

From lasering away your unwanted tattoo to landing on the Moon, getting your new trainers delivered on time, asking your AI to close the curtains, or buying a drink and a sandwich with coins, you have to be grateful to that genius of 300 years ago who still affects our everyday lives in the twenty-first century – Sir Isaac Newton.

News-worthy Item: There is a story that Isaac Newton invented the cat-flap. Whenever he began a mathematical or scientific project, Newton would become obsessed by it. He would forget to eat, wash, or change his shirt. During these times of complete immersion in his solitary work, how annoying it must have been to have to stop to let the cat out? We know he had a cat because it was said to have got very fat, eating at Newton’s forgotten meals. Newton had always been skilled at making things, from kites to model windmills as a child, to grinding lenses, polishing mirrors, and constructing telescopes. The bit of carpentry required to cut a hole in a door and fix a flap would have been well within his capabilities and eminently practical. So, all you cat – and dog – lovers probably have Isaac Newton to thank for this time-saving convenience. 

Newton’s astrolabe at Woolsthorpe Manor. (GM, The World of Isaac Newton, Amberley Publishing)

Q.1.        I decided to write this book, The World of Isaac Newton because I had always been inspired by Newton in my former scientific career. When Amberley asked me if I would write a book for their ‘In the Footsteps of...’ series, I immediately thought of him but there was a problem: Newton was born and educated in Lincolnshire, spent decades at Cambridge University and almost all the remaining decades of his long life in London. Therefore, to follow in his physical footsteps would produce a very slim volume. However, his scientific footsteps gave far greater scope. But dozens of biographies of Newton have already been written by people who are experts in science, some academic treatises, others aimed at the more popular market. I wanted to set Newton in his historical times, looking at the background to his ways of thinking and seeing the world as he would have experienced it. This new perspective was my reason for writing The World of Isaac Newton.    

Q.2.        Some of the most surprising things I learned during my research included the ideas the ancients had about the world. The Hebrew Old Testament describes the Earth as a sphere suspended from nothing. That must have been a tricky concept to get your head around in 2000 BCE. Also, in medieval times, when the Earth was still firmly at the centre of the universe, scholars were arguing that an omniscient God could have created innumerable habitable worlds, if He so desired, but he had decided on just one: Earth.

Q.3.        What is new and sets my book apart from others in the field is the idea of putting Newton in his historical context. His ideas were revolutionary but didn’t just appear by magic. Newton read widely on any and every subject that interested him, gleaning information from classical, medieval, and contemporary sources, from correspondence and acquaintances. Once he had that information, he asked endless ‘queries’, as he called them: Why did this happen? How could that be explained in mathematical terms? What would happen if? Newton was a Puritan in outlook because of the times in which he was born and educated, causing him to develop an incredible work ethic and a need to learn more about Creation to better understand God. To appreciate his attitudes and to uncover the influences of historical events behind his ideas was my intention, giving an original perspective on Newton’s life and achievements.   

Q.4.        One eye-opening statistic was to discover that Newton lived in a young persons’ world. In the early eighteenth century when he and his fellows were getting old – Sir Christopher Wren died aged 90, Newton was 84 and his friend Edmund Halley was 85 – the elderly were in a minority; over 25% of the population of Britain was of apprenticeship age: roughly, between 14 and 21.

Q.5.        My book uncovered the intriguing story – it may be a myth – that Newton invented the cat-flap so his pet mouser could come and go without disturbing his master, busy with his experiments and calculations, to open the door.

Q.6.        The single most important fact revealed in my book is probably that the most important facts about the secretive Newton’s life will never be revealed. After his death, a great number of his most private papers were burned by his nephew, John Conduitt, who thought they were too controversial ever to be made public.

Q.7.        I envision the lasting impact of my book to be, hopefully, a new way of thinking about Newton, seeing him as not only a genius for all time but also a man of his own time, influenced by the people, the ideas and the history happening around him.

Q.8.        I hope people will take away from reading my book the realisation that history, science, social settings, religious ideas, and political situations all intertwine. Nothing exists in isolation and it’s best to take a holistic view of the world with broad horizons.

Toni Mount's book The World of Isaac Newton is available for purchase now.