Capable Men of History: Isaac Newton

Throughout our lives, many myths and fables surround us, especially as a kid. Some myths have related to scientific facts and studies, while some are entirely a work of the human imagination.

These myths often started during the medieval ages, when people don’t usually study science. Interestingly, their works produced positive results – even without them knowing the scientific explanation behind. Because of this, alchemist gained popularity during the medieval era since they always attribute their work with magical powers. One famous myth about alchemists is that they can use their powers to form gold out of cheaper metals.

Isaac Newton (December 25, 1642 – March 20, 1727) was an English physicist, mathematician, astronomer, author, and theologian. He is widely recognized as one of the most influential scientists of all time. He was best known for his theory about the law of gravity, and his book, “Principia Mathematica” (1986), which greatly influenced the Enlightenment in Europe as it laid the foundations of classical mechanics.


Born in 1643 in Woolsthorpe England, Isaac Newton began to develop his theories of calculus and laws of motion that would later make him famous all throughout history.

He was a professor of mathematics at the University of Cambridge and a fellow of Trinity College. Following an outbreak of the bubonic plague in England, Cambridge University was closed, and Newton was forced to return home. The plague set the stage for one of his famous insights. It was a famous science story that Newton theorized the law of gravity after seeing an apple fall from a tree. That’s true – while he was sitting in the garden one day, quarantined because of the plague, he saw an apple fall from a tree, which provided him with the inspiration to formulate his law of universal gravitation. Newton also conceived theories of calculus and laws of motion during this period of isolation.

Principia Mathematica

Newton’s book, the Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy) was a foundation for modern science as we know it. It took two years for Newton to write, and it was a culmination of more than 20 years of thinking. This work cemented his reputation and contains much of what he is remembered for today.

The book Principia primarily deals with massive bodies in motion, initially under a variety of conditions and hypothetical laws of force. It’s a three-volume book that covers these areas:

  • Estimates of relative masses for Earth, Sun and other known giant planets
  • Astronomical evidence that proves the inverse square law of gravitation
  • The motion of the Sun relative to the solar system
  • The oblate spheroid figure of the Earth
  • The tides by its varying gravitational attractions of the Sun and Moon on the Earth’s waters
  • The precession of equinoxes as an effect of the gravitational attraction of the Moon to the Earth’s equatorial bulge
  • The theoretical basis for comets and their elongated, near-parabolic orbits

Book 1: De motu corporum (On the motion of bodies)

This book brings proof to Kepler’s second law, which states that if a continuous centripetal force is considered on the planet during its orbit, the area of the triangles defined by the path of the planet will be the same. It relates circular velocity and radius of path-curvature to radial force.

The book opens with a mathematical exposition of a geometrical form of infinitesimal calculus. It also deals with the motion of bodies that are drawn to one another by centripetal forces and its application to the Solar System, and the attractive forces of spherical bodies.

Book 2: Part 2 of De motu corporum

In Book 2, Newton examined the laws of resistance and discussed it in direct proportion to velocity. Newton also discussed the implications of resistance in proportion to the square of velocity.

This book also tackles hydrostatics, effects of air resistance on pendulums, the speed of waves in fluid in relation to density and condensation. He also derives Boyle’s law.

Book 3: De mundi systemate (on the system of the world)

The Book 3 exposes many consequences of universal gravitation in astronomy. It builds upon the proposition in Book 1 to the motions observed in the solar system. It also considers the harmonic oscillator and motion in arbitrary force laws.

This book also made it clear that Newton had a heliocentric view of the Solar System.

To reduce the risk of public misunderstanding, Newton included at the beginning of Book 3 in the second and third editions, a section called “Rules of Reasoning in Philosophy.” Those four rules offer a methodology for handling unknown natural phenomena and reaching towards explanations for them.

Rule 1: We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.

Rule 2: Therefore, to the same natural effects we must, as far as possible, assign the same causes.

Rule 3: The qualities of bodies, which admit neither intensification nor remission of degrees, and which are found to belong to all bodies within reach of our experiments, are to be esteemed the universal qualities of all bodies whatsoever.

Rule 4: In experimental philosophy, we are to look upon propositions inferred by general induction from phenomena as accurately or very nearly true, notwithstanding any contrary hypothesis that may be imagined, till such time as other phenomena occur, by which they may either be made more accurate or liable to exceptions.

Other Significant Discoveries

Newton was driven by the belief that true knowledge can be gained by making observations rather than reading. For instance, he did not just trust texts and studies on optics – he experimented by sticking a blunt needle in his eye to see its effect. From there, he wrote about his theory of optics that made him reconsider the design of the telescope. Before his discovery, telescopes were large, cumbersome instruments. By using mirrors instead of lenses, Newton was able to upgrade the telescope into a more powerful instrument that’s ten times smaller than traditional telescopes. It was the first practical reflecting telescope based on the observation that a prism separates white light from the colors of the visible spectrum. His work on this area was written on his highly influential book Opticks (1704).

Newton also formulated the empirical law of cooling, introduced the notion of a Newtonian fluid, and made the first theoretical calculation of the speed of sound.

When critics from the Royal Society criticized his theories about light, Newton did not take it well. He had an ugly temper and a conviction that he was right. When his pride was dented, he began to withdraw from intellectual life. He returned home to Woolsthorpe for a self-exile and solitary study.

So, besides his scientific endeavors, Newton also spent much of his life pursuing alchemy, whose goal is to find the philosopher’s stone. In the 17th century, alchemists were searching for this substance that can allegedly turn ordinary metals like iron and lead to gold. He was secretive about his alchemy experiments and recorded some of it in code.

Newton also analyzed the Bible to find secret messages on how the universe works.


On success

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

My powers are ordinary. Only my application brings me success.

If others would think as hard as I did, then they would get similar results.

On patience

If I have done the public any service, it is due to my patient thought.

Genius is patience.

If I have ever made any valuable discoveries, it has been due more to patient attention than to any other talent.

On truth

Truth is ever to be found in simplicity, and not in the multiplicity and confusion of things.

To myself, I am only a child playing on the beach, while vast oceans of truth lie undiscovered before me.

A man may imagine things that are false, but he can only understand things that are true.

Truth is the offspring of silence and meditation. I keep the subject constantly before me and wait ’til the first dawning opens slowly, by little and little, into a full and clear light.

Plato is my friend, Aristotle is my friend, but my greatest friend is truth.

On science

No great discovery was ever made without a bold guess.

To every action, there is always opposed an equal reaction.

Everybody continues in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed upon it.

What we know is a drop; what we don’t know is an ocean.

Gravity explains the motions of the planets, but it cannot explain who sets the planets in motion.

It is the weight, not numbers of experiments that is to be regarded.

On God

This most beautiful system of the Sun, planets and comets, could only proceed from the counsel and dominion of an intelligent and powerful Being.

He who thinks half-heartedly will not believe in God, but he who really thinks has to believe in God.

In the absence of any other proof, the thumb alone would convince me of God’s existence.

Don’t doubt the Creator because it is inconceivable that accidents alone could be the controller of this universe.

As a blind man has no idea of colors, so have we no idea of the manner by which the all-wise God perceives and understands all things.

On life

Live your life as an exclamation rather than an explanation.

I can calculate the motion of heavenly bodies, but not the madness of people.

What goes up must come down.

We build too many walls and not enough bridges.