There really is no way to understate the influence that Isaac Newton had on modern science. From his discovery of the laws of gravity and motion to his work developing the math behind Calculus to his role in the creation of the Royal Society, Isaac Newton was one of the most consequential scientific figures in history.
Responsible for discoveries in math, physics, and optics, his 1687 work Philosophiæ Naturalis Principia Mathematica is considered one of the greatest scientific works ever written and lays the foundations for classical mechanics and the theory of gravity, which dominated the field of physics until Einstein's theory of relativity took its place in the early 20th century.
Coming from rather humble, though not impoverished, beginnings, Newton did not seem like someone destined to leave so large a mark on the field of science and math. A decent enough student, he came upon the scientific scene just as the Scientific Revolution was hitting its stride in the 17th century, and his work could easily be considered that Revolution's apex.
Early life and career
Sir Isaac Newton was born on January 4, 1643 (December 25, 1642 according to the Julian calendar used in England at the time), in Woolsthorpe, Lincolnshire, England.
The son of a reasonably well-off farming family, his father died a few months before he was born. Newton himself was a premature infant who was not expected to live. He obviously survived infancy, but spent his formative early years living with his maternal grandmother, after his mother remarried.
A gifted child, Newton was said to be taken with building models, including a small, working flour mill that used a mouse running in a wheel for power, and an elaborate system of sundials which was accurate to the minute.
His early education was disrupted when his family tried to make a farmer out of him, but he found it incredibly boring.
His family acquiesced and returned him to school. He later enrolled in Trinity College at the University of Cambridge, in 1661, where he studied law and paid for his education and upkeep by working as a servant and cleaning up the rooms of wealthier students.
The university closed in 1665 after an outbreak of Bubonic plague ripped through England, and he returned home during this time. The apocryphal story of the apple falling from a tree inspiring Newton's discovery of the laws of gravity is said to have occurred at this time, but is almost certainly a myth. Whatever happened in the two years that Newton spent away from Cambridge, he certainly made the most of this time.
Shortly before Cambridge closed in 1665, Isaac Newton developed the generalized binomial theorem, an important part of elementary algebra. During his time at home, Newton made major strides in his theory of gravitation, calculus, and optics, much of which would be formally published later in his career.
His De analysi per aequationes numero terminorum infinitas, contributed to important progress in the mathematical field of infinite series and was decribed by a leading British mathematician at the time and Newton's mentor, Isaac Barrow, as the work "of an extraordinary genius."
Newton, upon his return to Cambridge in 1667, took up a position as a Fellow at Trinity College. This technically required him to become a member of the clergy of the Church of England, but Newton's "unconventional" religious views for the time stood in the way and would be a point of contention for many years until he was given a special dispensation to avoid becoming ordained by King Charles II.
One of Newton's first major inventions was a function of his duties as a Fellow of the College, which required him to give lectures at the university. He chose to lecture on optics for his first few years, from 1670 to 1672 and, to prove his theories about the nature of light and color, he invented the first-known telescope that used reflecting mirrors instead of lenses.
His work on optics, principally that white light entering through a prism produced a spectrum of color that could then be reformed into white light using a lens and a second prism, settled an ongoing debate about the nature of color. Newton showed that color was a feature of light itself, not of the object being illuminated, known as Newton's theory of color.
In a bit of foreshadowing of the course of his life, Newton was invited to share his ideas about light with The Royal Society, the elite scientific community that helped drive the Scientific Revolution in Britain and beyond.
Newton described his experiments with light in a less-than straightforward manner, which meant the Society's members could not reproduce Newton's results. When Robert Hooke criticized Newton's findings on light and color, Newton took the experience badly and saw the essential criticism of peer review as a personal attack.
This led Newton to withdraw from intellectual society for many years, delaying the publication of many of his most important works for more than a decade. Though he would return in time and eventually rose to lead The Royal Society as President, this absence from the academic scene would lay the foundation for one of the greatest scientific controversies in history.
Defining Calculus and beefing with Gottfried Leibniz
While it's universally recognized in academia that German mathematician Gottfried Wilhelm Leibniz independently co-invented Calculus with Isaac Newton, Newton would beg to differ - and he begged with an absolute vengeance.
So-called priority fights are a pretty big deal in a field where discoveries of important laws or phenomena are the currency of the realm, and it doesn't get much bigger than Calculus.
Calculus is the mathematical bedrock of all kinds of scientific disciplines, owing largely to its ability to measure rates of change or to extrapolate greater data from smaller data, such as the surface area and volume of complex shapes.
Newton had to invent calculus in order to explain many of his discoveries around gravitation and classical mechanics, but he did not publish these findings until 1704, and even then in a somewhat muddled way.
Meanwhile, in Germany, Leibniz — an accomplished scientist and mathematician in his own right, had laid down the same math in a cleaner, more efficient manner in 1684, along with the conventional notation used around the world today.
Newton and his allies accused Leibniz of plagiarism, and Newton used his stature and position as the President of The Royal Society to destroy the reputation of Leibniz, an effort that was largely successful. It has only been in recent years that Leibniz has been given his fair share of the credit for the invention of Calculus.
Philosophiæ Naturalis Principia Mathematica
Probably the greatest of Isaac Newton's discoveries was laid down in Philosophiæ Naturalis Principia Mathematica in 1687, known today as Newton's Laws of Motion.
This foundational work of modern physics demonstrated and explained how macroscopic objects moved, both on Earth and in the heavens, according to the same mathematical laws and could be explained with three essential principles, often stated as:
- An object at rest will remain at rest and an object in motion will remain in motion at a constant speed in a straight line unless an outside force acts upon it.
- An object's acceleration is a function of the object's mass and the quantifiable amount of force applied to the object.
- When an object acts against another object, the second object reacts in an equal and opposite manner against the first.
The first law, that of inertia, explains how objects in motion and at rest "prefer" to keep their existing state as-is and resists change unless compelled by some force. This helps to explain acceleration, deceleration, and the like.
The second law, that of force, can be summed up in the equation:
Force = mass x acceleration
This formula is essential to the mechanics of motion and defines the math that governs how the first law of motion actually works in practice — that is, how much force needs to be applied to overcome an object's inertia.
The third law, that of action and reaction, defines motion as an interaction of complementary forces. In the case of an airplane, the shape of the wing pushes air down. In response, the air pushes against the shape of the wing, lifting it up.
The wing, attached to a fuselage, pushes the plane up. The weight of the fuselage, attached to the wing, pulls the wing down against the air in response.
There is much more that could be said about the Principia and its impact on modern science, but for now, it's enough to say that it remained the bedrock of physical sciences for centuries and is still highly relevant even to this day.
Suppressed work in alchemy and divination
With the publication of Principia, Opticks, and many other works, Newton pretty much cemented himself as one of the greatest scientific minds in human history — but he was still a man of his time.
In the 17th century, alchemy was falling out of favor but was still practiced, being pursued with all its fruitless attempts at turning lead into gold and uncovering the secrets of immortality through the fabled Philosopher's Stone.
During the period of self-imposed exile following the poor reception of his work in optics, Newton dove deep into some less-than-scientific pursuits.
Newton devoted a considerable amount of effort to alchemical studies, and it's estimated that his surviving papers, collected after his death, amount to an estimated 10 million words, enough to fill an entire bookcase in a library on their own.
Of those 10 million words, a surprisingly large number pertained to alchemical formulas and forensic study of the Bible in search of hidden codes and prophecies.
The religious conjectures he put in writing, including his rejection of the essential Christian doctrine of the Holy Trinity, would have branded him as a heretic in the eyes of the public, and his pursuit of a philosopher's stone that could grant immortality would be an embarrassment for a figure of Newton's stature, at least in the eyes of many of his supporters.
As a result, his legal heir, John Conduitt, the husband of Catherine Barton, Newton's half-niece, kept these papers under wraps and they would not begin to see the light of day until the middle of the 20th century, when many of them started to see widespread publication.
Final, cantankerous years
Isaac Newton was known to have a mean streak, including making threats and lashing out at friend and enemy alike. Speculations have long been made about his personal relationships, or lack thereof, by both modern figures and his contemporaries.
In one letter to his friend, the political philosopher John Locke, Newton wrote: "SIR, — Being of opinion that you endeavoured to embroil me with women, and by other means, I was so much affected with it, as that when one told me you were sickly and would not live, I answered, 'twere better if you were dead. I desire you to forgive me this uncharitableness."
Robert Hooke certainly didn't set out to make Newton his enemy, but Newton nonetheless held a grudge over the legitimate scientific criticism of his work and used his position as President of the Royal Society to attempt to erase Hooke's contributions from history.
He engaged in another nasty fight with British astronomer John Flamsteed in 1712. Flamsteed had dedicated much of his scientific efforts toward producing a definitive star catalogue full of rich and precise detail.
Newton was impatient with Flamsteed's fastidiousness regarding his data and turned over large chunks of it to astronomer Edmond Halley (of Halley's Comet fame) to edit. Newton then published the error-filled volume of Historia Colestis Britannica without Flamsteed's consent.
Horrified and humiliated, Flamsteed spent a considerable sum buying up all the copies of the slapdash volume he could and proceeded to make a show of openly burning them at the Royal Observatory. Newton was not amused, and stripped any mention of Flamsteed from his Principia Mathematica, even though Flamsteed's contributions to the work were substantial.
Newton's ruthlessness wasn't reserved for the academy either. In 1696, Newton was tasked with overhauling the British currency as warden and later Master of the Royal Mint, where he ruthlessly pursued counterfeiters, going so far as executing known offenders.
Death and Legacy
Sir Isaac Newton died in his sleep on March 31, 1727. He was given a state funeral and buried in a tomb in Westminster Abbey in London — far more than his enemies received.
It's undeniable though that Isaac Newton, as difficult as he might have been to deal with personally, was still an extraordinary figure and one of the greatest scientific minds humanity has ever produced.
His most important work on gravitation and motion, while later supplanted by the likes of Albert Einstein, served as the basis for modern physics for centuries.
Most important, perhaps, was Newton's methodical approach to his work and research, which helped define and codify what we know as the scientific method that undergirds all modern science. As Newton himself once said, "If I have seen further it is by standing on the shoulders of Giants."