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Sir Isaac Newton: A Great Mind That Changed the World


My writing interests are general, with expertise in science, history, biographies, and “how-to” topics. I have written over sixty books.

Isaac Newton

Isaac Newton

A Troubled Youth

Isaac Newton was born on January 4, 1643, in Woolsthorpe, near Grantham in Lincolnshire, England. It was a tumultuous time with the English Civil War raging, but Woolsthorpe was somewhat isolated from the problems that beset the country. Isaac was named after his father, a prosperous farmer who died three months before he was born. He was of premature birth and deemed unlikely to survive and to be “so little they could put him a quart pot.”

Before Isaac turned three years old, his mother, Hanna Ayscough Newton, remarried. From then on, his grandmother took care of Isaac because his mother wanted to have a new family with her new husband, a wealthy preacher named Barnabas Smith. Isaac’s mother and stepfather had two daughters and a son. It was only after Barnabas died in 1653 that Isaac could live with his mother again. Isaac was twelve years old when he was reunited with his mother and became acquainted with his half-siblings. These events from his childhood are often cited as the foundation for Newton’s emotional upheaval in adulthood. Despite his genius, Newton’s adult life was filled with anxiety and punctuated with venomous attacks toward friends and enemies alike.

At school he was taught very little of what we would call science today; nevertheless, young Newton began to show an interest in the natural world. He had a talent for making things, drawing, and sketching. His skill in drawing may have been enhanced by the instruction divulged in one of his favorite books, Mysteries of Nature and Art. As is evident in his copious notebooks, the book played a major role in stirring his interest in science. The book, which was written in 1634, was a rambling collection of secrets, wonders, recipes, and folklore. The section of the book called “Sundry Experiments” inspired the young genius to start investigating the natural world.

By the time he was reunited with his mother, Newton was already studying in Lincolnshire, at King’s School in Grantham. Needing a place to stay while in Grantham, he lodged with the local apothecary, John Clark, who was associated with the school and routinely boarded students at his house. While he was living with the Clark family, he filled his room with drawings, built sundials, and supposedly had his first romance with a neighborhood girl. The most important consequence of Newton’s stay at the Clark’s appears to have been more intellectual than social, however. Mr. Clark encouraged the boy to help him in the shop, mixing potions, salves, and medicines. It was here he learned the rudiments of chemistry.

Though Newton was a bright and inquisitive young man, his mother wanted him to work on their farm. The everyday chores of running a farm didn’t interest Newton; tales abound of his lack of interest, absentmindedness, carelessness, and general lack of fitness to be a gentleman farmer. Because he wasn’t suited to be a farmer, he was sent back to school. The young man had a keen intellect that was evident to those who knew him. Nevertheless, he did not excel as a student; doing just well enough to graduate and qualify for higher education. An uncle recommended that Isaac enroll in his alma mater, the University of Cambridge’s Trinity College, where he might thrive.

Newton's childhood home in Woolsthrope, Lincolnshire, England.

Newton's childhood home in Woolsthrope, Lincolnshire, England.

Cambridge University

Cambridge, England in the 1600s was a small city located at the crossroads of two important trade routes, the Great North Road and the waterways of the Fen to the east. The population was around 7,000 with nearly half the residents associated with the University in some fashion. To serve the needs of the men of the university, the city offered a variety of inns, taverns, prostitutes, and a host of thieves ready to relieve the naïve young men of their money. In 1661, Isaac Newton was accepted into Cambridge University on a program similar to a modern-day work-study program. To support his daily expenses, Isaac maintained the rooms of wealthy students and waited tables at the dining hall.

During the seventeenth century the curriculum at Cambridge was focused on classical authors. It was perhaps this kind of structure that motivated Newton to engross himself in private study. To satisfy his own curiosity he delved into learning about some of the most important names in the scientific revolution, such as Pierre Gassendi, René Descartes, and Thomas Hobbes. His interest in mathematics led him to read Geometrie by Descartes and the works of Euclid. He completed his bachelor’s degree without honors in 1665.

The great plague of 1665.

The great plague of 1665.

The Plague Years

From a distant European or Mediterranean port, a ship docked in London sometime in 1665. In the ship’s hold were rats, which carried fleas, which were infected with virulent bubonic plague bacteria also called the “Black Death.” The plague spread quickly throughout London and into the countryside. Since no one was sure exactly how the plague spread, quarantine was the only effective way to handle the deadly disease. London suffered the most with over 70,000 dead. Fearing the worst, Cambridge University closed up shop in 1665 and 1666. The stringent measures proved effective, with deaths below a thousand in the city of Cambridge. The college escaped the brunt of the disease, probably because the students and fellows were sent home, including the twenty-two-year-old Isaac Newton.

Newton spent his days at home in Woolsthorpe as the dreaded Black Death ravaged the cities and towns. According to the young thinker, these fortuitous eighteen months were the prime age of his invention. Later in life he was asked about the nearly two very productive years he spent at home and explained, “I keep the subject constantly before me and wait ‘till the first dawnings open slowly, by little and little, into a full and clear light.” Also remarking, “Truth is the offspring of silence and mediation.” The time spent in solitary study and experimentation was one of his most productive periods, during which he made original contributions to calculus, optics, and planetary motion.

Once the university re-opened its doors, Newton returned and became a fellow at Trinity College, where he spent most of the next three years giving lectures. In 1669, Newton was elected the Lucasian Professor of Mathematics, a position he would hold for the next 34 years. In 1671, Newton became a Fellow of the Royal Society of London–an organization he would be associated with for the remainder of his life.

Newton the Alchemist

Before the dawn of the Scientific Revolution, science or natural philosophy, mysticism, and religion mingled as one. In that world the most sought-after prize was the Philosopher’s Stone, a mystical substance which had many wonderful powers, including turning base metals into gold. Those who sought the Philosopher’s Stone were known as alchemists. In addition to their quest for gold, the alchemists were in search of elixir vitae, the elixir of life, a potion that conveyed immortality to the drinker. In search of these aims, the alchemist mixed powders and potions, heated and distilled combinations of mercury, iron, acid and many other exotic substances. Since much of this experimentation was done in secret, the language of chemistry was not used; rather, a system of strange names and obscure symbols, allegory, and code. Isaac Newton was counted among the ranks of the alchemists secretly seeking the Philosopher’s Stone. Newton was not alone in his quest, as many of his most illustrious contemporaries, such as Robert Boyle, were also engaged in alchemical research.

For Newton the true gold of alchemy was far beyond the riches of wealth, it was the attainment of the ultimate truth. According to the prevailing view of history at the time, mankind once possessed this great knowledge but now it was lost. Newton believed that these deep secrets were still accessible, though hidden in the natural world, waiting for those who could unravel the mystery. John Maynard Keynes wrote that Newton “regarded the universe as cryptogram set by the Almighty,” and alchemy held the key to decode these ancient truths. Newton believed himself up for the task, for to be a successful alchemist, one must have pure intentions and undergo a program of physical and spiritual purification. As a pious person, and almost certainly a virgin, Newton with his unparalleled powers of concentration was a perfect candidate to delve into the murky water of alchemy. He wrote to a friend of his pursuit: “They who search after the Philosopher’s Stone are by their own rules obligated to a strict and religious life. That study is fruitful of experiments.”

Newton began his study of alchemy as he did any other subject and threw himself headlong into his work and began to read everything he could on the obscure subject. At Cambridge after the great plague, he began to compile a glossary of chemical terms, much of which were based on the book by Robert Boyle, The Scptical Chymist. The wealthy Boyle was a founding member of the Royal Society and a proponent of experimentation to unravel nature’s mysteries. Boyle had great influence on the young Newton, in terms of both science and alchemy.

Around 1669, Newton launched into alchemy research, working long hours many times with little sleep. According to Betty Jo Teeter Dobbs, a scholar of Newton’s alchemy, “Each brief and often abruptly cryptic laboratory report hides behind itself untold hours with hand-built furnaces of brick, with crucible, with mortar and pestle, with the apparatus of distillation, and with charcoal fires: experimental sequences sometimes ran for weeks, months, or even years.”

The years of toil and study didn’t reveal to Newton the Philosopher’s Stone but it did develop his skills in the laboratory. Over time he became somewhat of an expert on the construction of furnaces and the proper handling of vile and dangerous chemicals. In the winter of 1677-78, disaster struck in the form of a laboratory fire. Although Newton’s laboratory was not completely destroyed, many of his papers and manuscripts were destroyed, and much of his research into alchemy went up in flames.

Though Newton would ultimately return to purely scientific investigations, he would dabble in the hidden world of alchemy up until the 1690s. Over his lifelong interest in the subject, he acquired many texts on the art of alchemy. According to Michael White, author of Isaac Newton: The Last Sorcerer, “It has been said that Newton possessed the finest and most extensive collection of alchemical texts ever accumulated up to his day.”

Painting "The Alchemist" by Sir William Fettes Douglas.

Painting "The Alchemist" by Sir William Fettes Douglas.

The Scientific Revolution Begins

Since ancient times man has gazed at the night sky and marveled at its beauty while pondering the motion of the planets as they dance across the unmoving stars. The Polish priest and astronomer Nicholas Copernicus determined the sun was at the center of the solar system over a hundred years before Newton but couldn’t formulate the mathematical equations that governed the motion of the moon and the planets as they traverse the night sky. Unraveling this cosmic mystery was one of Newton’s greatest achievements.

It took almost twenty years before his ideas on gravitation evolved into full-blown theory. According to legend, Newton’s observations of a falling apple in 1666 while deep in thought at Woolsthorpe led him to consider the effects of gravity. Based on this story, the falling apple led Newton to think about the parallels between the behavior of the falling apple and the motion of the moon around the earth. Beginning in 1679, he began a yearlong correspondence with the scientist Robert Hooke in which they discussed their understanding of what caused two celestial bodies to be attracted to each other. By 1680, Isaac Newton had come to his own conclusions about gravitation. His studies on planetary motion astronomy helped him consolidate his theories. Before Newton’s revolutionary ideas on gravity and the motion of celestial bodies, the current thinking had been that the attraction between bodies separated by empty space was mediated by unseen particles.

Newton made mathematical calculations to determine the force required to hold the moon in its orbit around the earth, comparing it to the force required to pull an object toward the ground; for example, an apple. Additionally, he calculated the relationship between the length of a pendulum and its swing direction, as well as the amount of force required to keep a stone from falling off a sling while being launched. Newton’s calculations motivated him to correspond with astronomer Edmond Halley in 1684. Newton told Halley that the path of a body that is subjected to a centrally directed force is that of an ellipse. He also explained the relationship between the force and the distance between two bodies. Newton wrote a brief tract on mechanics, which would later be incorporated into his seminal work, the Principia.


The Principia

The Philosophiae Naturalis Principia Mathematica, or the Mathematical Principles of Natural Philosophy, was Newton’s finest contribution to scientific knowledge. The manuscript was published in 1687 in Latin. Newton continued revise his work and published updated versions of the Principia in 1713 and 1726.

Book I of the Principia revolves around the discussion of the foundations of mathematics and science. Here, Newton discussed the role of gravitational force as fundamental to the motion of all celestial bodies. In this section of the publication, he explored the nuances of orbital motion around centers of force.

In Book II, he introduced his theory of fluids, particularly motion through fluids and pertinent problems involved in the movement of fluids. In Book III, Newton discussed the influence of gravitation in the solar system using measurements of the six known planets. The laws he formulated also encompassed the observed behavior of comets, but they still did not fully explain the motions of the moon. His computations on the precession of the equinoxes and the tidal ebb and flow were accurate. Based on his conclusions, he was able to postulate the relative masses of the heavenly bodies.

When Newton presented his three laws of motion and the laws of universal gravitation, as well as other concepts and computations concerning the celestial bodies, he was definitely ahead of his time. His theories are now considered among the greatest achievements in abstract human thought. Before the modern theories of Relativity and Quantum Mechanics came to prominence, Newton’s theory of motion was the accepted law until the late 19th century. After immediate acceptance by the scientific community in Britain, the rest of the world followed suit, and Newton’s Laws became universal laws in just fifty years. Other scientists, including distinguished astronomer and mathematician Pierre-Simon Laplace, expanded Newton’s work to explain natural phenomena.

Sir Isaac Newton Biography

Work in Optics

The Principia was followed by Newton’s Opticks: Or a Treatise of the Reflections, Refractions, Inflections & Colours of Light, as well as Two Treatises of the Species and Magnitude of Curvilinear Figures. Opticks was published in London in 1704. Unlike his previous works, this treatise was published in English, with a revised scholarly edition, written in Latin, published in 1706.

The scope of Newton’s Opticks encompasses his theories on color and the light spectrum. His discussion included the refractive properties of different colors, a theory on the formation of a rainbow, and the workings of a refracting telescope, and he devised a color circle. Newton’s work revolved around the behavior of light with the use of lenses, prisms, and sheets of glass.

In this second major publication, Newton presented pioneering experiments in support of the corpuscular theory of light, which Newton favored over the theory of light existing in the form of a wave. The book differs from the Principia mostly because it presents deductions made from experiments that demonstrate how light is absorbed, reflected, and transmitted. Nevertheless, it remains one of the most important treatises ever written on the nature of light and color. One of the major findings Newton presented overturned the belief that sunlight is colorless, as proposed by the Greek philosopher Aristotle. Newton presented sufficient evidence that “pure” light is not altered into different colors due to interactions with matter. Instead, light is innately composed of seven different spectral hues. In 1672, Newton wrote to Henry Oldenburg describing his experiment with light and a prism: “I procured me a triangular-glass prism, to try therewith the celebrated phenomena of colors. And in order thereto having darkened my chamber, and made a small hole in my window-shuts, to let in a convenient quantity of the sun’s light, I placed my prism at its entrance, that it might be thereby refracted to the opposite wall. It was at first a very pleasing divertissement, to view the vivid and intense colors produced thereby…”

Newton's reflecting telescope.

Newton's reflecting telescope.

Newton’s Reflecting Telescope

The Dutch spectacle maker Hans Lippershey invented the first telescope in 1608. The device was rather crude and found more use as a parlor toy than as a serious instrument. A few years later, the Italian astronomer Galileo Galilei made improvements to the instrument to make the first scientifically important observations of stars and planets. When Newton began to investigate the refracting telescope, which is made from two lens, he noticed that here were small rainbow images around bright objects – the effect is called chromatic aberration today. To solve this problem Newton devised a reflecting telescope that used a polished parabolic mirror to focus the light. The problem was with the mirror, seventeenth-century technology was such that the best opticians in England had failed to make a usable parabolic shaped mirror. To remedy the situation, Newton employed his alchemical expertise to concoct an alloy with the perfect combination of reflectivity and harness. In early 1669, after exhaustive labors casting, grinding, polishing the mirror, making the tube and mount, he succeeded in crafting a small and sturdy telescope, just six inches long. He wrote to a friend that I could magnify objects “about 40 times in diameter which is more than an 6 foot tube [refracting telescope] can do, I believe with distinctness…I have seen with it Jupiter distinctly around and his satellites, and Venus horned.” The reflecting telescope has become the work horse of modern astronomy with mirrors on today’s modern giant telescopes many feet in diameter.

If I have seen further than others, it is by standing upon the shoulders of giants.

— Isaac Newton

Newton the Public Figure

Newton had a short and undistinguished career in politics when in 1689 he became a member of parliament for the University of Cambridge to Parliament. In 1696, he was appointed Warden of the Royal Mint, where he served as an able administrator. In 1699, he was promoted to Master of the Mint, a position he held until his death many years later.

As a result of his growing prestige, Newton was elected President of the Royal Society of London in 1703. He continued to play a part in the development of science throughout his tenure there. He was an autocratic and controversial figure who exercised absolute control over younger members. He also entered into controversial disputes with his colleagues, including English astronomer John Flamsteed, German philosopher and mathematician Gottfried Wilhelm von Leibniz, and the English natural philosopher Robert Hooke. Among his peers, he was known for his unreasonable behavior and quickness to anger, particularly when his ideas were criticized or opposed. He tended to harbor resentment and hold grudges against his adversaries.

Newton was knighted by Queen Anne in 1705, making him the second scientist to receive the accolade after Sir Francis Bacon in 1703. In the last few years of the eighteenth century, Sir Isaac Newton enjoyed the distinction of being recognized as the foremost natural philosopher in Europe. His publications had their share of critics, but Newtonian Science was spreading and gaining wider acceptance. To this day, Sir Isaac Newton is considered one of the most influential theorists, and one of the most formidable original thinkers who ever lived.

Newton's drawing of Solomon's Temple.

Newton's drawing of Solomon's Temple.

Newton the Theologian

By the time Opticks was published, Newton’s career as an active scientist was drawing to a close. He did continue to research and update some of his earlier work until the last years of his life. From his time at Trinity College, Newton had been a student of the Bible. The Book of Revelation and the Book of Daniel particularly intrigued him–these books were clues from God about the story of creation. To try to unravel the mysteries of the Bible, Newton engaged in exhaustive research to trace the history of scripture in order to match prophecy with history. In one of his first theological writings from his early days at Trinity College, he wrote regarding the Book of Revelation: “There is no book in all the scriptures so much recommended & guarded by providence as this.” He approached the deciphering of the scriptures with the same rigorous analytical method that he applied to his study of natural philosophy. After his death, his discourse on the prophecies was eventually published as Observations upon the Prophecies.

Newton's burial crypt at Westminster Abbey

Newton's burial crypt at Westminster Abbey

Final Days

Despite his personal asceticism, Newton could be quite generous with his family members. Although he had no full brothers or sisters and no children, he was often happy to help out his relatives financially. As he grew in years so did his wealth. His work at the Mint paid well, and the inheritance from his mother was considerable and added to his purse. Though he was a confirmed bachelor during his long life, in his later years he enjoyed the role of family patriarch for his extended family. During his final years, his niece Catherine Barton came to live with him as his housekeeper. His day-to-day contact with her was possibly his only lasting relationship with a woman.

Sir Isaac Newton lived to be 84 years old and died on March 31, 1727. By the time of his death he was revered as a national treasure in Great Britain. He was afforded a grand states burial in Westminster Abbey, possibly the first man to have that distinction purely for his intellectual achievements.


Bate, John. THE MYSTERYES OF NATVRE AND ART. 1634. Available at: https://www.gutenberg.org/files/47837/47837-h/47837-h.htm

Gleick, James. Isaac Newton. Pantheon Books. 2003.

Levy, Joel. Newton’s Notebook: The Life, Times, and Discoveries of Sir Isaac Newton. Running Press. 2010.

West, Doug. A Short Biography of the Scientist Sir Isaac Newton. C&D Publications. 2015.

Questions & Answers

Question: Did Newton ever get married?

Answer: Newton never married and, though it's impossible to verify, is widely believed he died a virgin.

© 2019 Doug West


Doug West (author) from Missouri on October 14, 2019:


Back during Newton's time, physics, chemistry, astronomy, astrology, religion, and alchemy all ran together. They were all trying to learn more about nature but the method which scientists (philosophers) used to explore the world varied greatly.

Mohan Babu from Chennai, India on October 11, 2019:

Great article. It is fascinating that someone could differentiate planets and stars by mere observation back then. That he could explain gravity through the observed planetary motion was beyond belief. Newton was arguably the most brainy man to have ever walked on this planet. I did not know he started off as an alchemist.

Jeff Zod from Nairobi on September 17, 2019:

Hi Doug,

Your article on Sir Isaac Newton is a masterpiece! Thank you so much for writing such a wonderful article.

Tim Truzy from U.S.A. on September 17, 2019:

Thanks, Doug. I truly enjoyed this work. I didn't know Sir Newton had such a fiery personality, but we certainly remember his scientific contributions. He was an amazing man who gave science and the world much to build upon. Respect and admiration.

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