# The Brilliance of Sir Isaac Newton and His Legacy to Us

**By Dr. Gary Deel, Ph.D., J.D.**

*Faculty Director, **School of Business**, American Military University*

To say that Sir Isaac Newton was a genius is an unforgivable understatement. Many people alive today know his name from stories about falling apples giving rise to epiphanies as if Newton were some kind of 17th-century “Doc Brown.” But few truly appreciate the magnitude of the contributions that Newton made to our understanding of the cosmos, and the trajectory of progress for our species in the centuries that would follow his life.

**The Early Life of Isaac Newton**

Newton was born in 1642, and it was clear from an early age that he was exceptionally intelligent. He excelled in mathematics, science, philosophy and other academic endeavors.

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But in 1666, the bubonic plague ravaged England while Newton was studying at Cambridge University. Newton took refuge in the English countryside and stayed in the rural farmhouse in Lincolnshire where he was born. However, his curiosity about the universe and his thirst to understand the heavens never waned.

**Developing and Proving the Theory of Gravity**

Newton pondered the laws of motion that had been established by famed German astronomer Johannes Kepler a generation earlier. But Newton longed to understand how and why the celestial bodies move in the ways they do.

He intuitively deduced that these movements must be the product of gravity. Newton reasoned that the same force which draws apples hanging from trees to the Earth below them must be responsible for the movement of the Moon around the Earth and the planets around the Sun.

But Newton lacked the mathematical tools to prove his theory’s explanatory ability with respect to the movement of all the different bodies observable in the night sky. This wasn’t because Newton didn’t understand math well, but rather just the opposite. Newton brought all the tools of 17th-century mathematics and science to bear on the problem, but they were insufficient to make the logical connections that were necessary to prove Newton’s claims.

So what did Newton do? He invented new math, of course. That’s right: Newton *invented* integral and differential calculus for the purposes of solving the problems of motion in the cosmos that remained a mystery. This was a remarkable achievement because Newton was about 25 years old at the time.

I took Calculus I in college, and I was about the same age that Newton was when he invented it. I remember struggling sincerely to follow the mechanics and logic of the process.

In the end, I barely passed my class. But the notion that a 25-year-old invented those difficult concepts, working off nothing more than scientific curiosity, is staggering to me. And it convinces me that Newton must have been a truly special individual.

**Principles of Newtonian Mechanics**

With Newton’s new mathematical tools in hand, he completed his work and penned what we today call the principles of classical mechanics — or Newtonian mechanics — in honor of their discoverer. These principles consisted of three main laws:

- Newton’s first law, the law of inertia, states that objects at rest remain at rest. Objects in motion also remain in uniform motion, unless acted upon by an outside force.
- Newton’s second law states that the sum of forces (F) applied on an object is equal to the object’s mass (m) multiplied by its acceleration (a). An example is the famous physics equation
*F = ma*. - Newton’s third law, also known as the law of conservation of momentum, states that for every action, there is an equal and opposite reaction.

Newton codified these laws in his seminal work, “Principia,” in 1687. This treatise was eventually accepted by scientists around the world as the foremost authority on the mechanics of the universe for more than 200 years. It would not be until 1905 that Albert Einstein would make the next material leap forward beyond Newton in explaining our universe with his laws of special and general relativity.

**Newton Was Also a Leader in the Optics Field**

In addition to his work in physics, Newton was also a luminary in the field of optics. Newton used telescopes to observe and study the comings and goings of celestial bodies as he was working on his classical mechanics theories.

However, he ran into limitations with the traditional refractor telescopes of his day. These scopes have their strengths, but they also suffer from inherent challenges, such as chromatic aberrations caused by the lenses that separate white light into its constituent colors.

So what did Newton do? You guessed it — he invented a new telescope.

Newton developed the first reflector telescope that sidesteps problems like chromatic aberration and yields much clearer views of the cosmos. This kind of telescope would eventually become known as the Newtonian reflector. All serious telescopes today — from ground-based observatories to the legendary Hubble Space Telescope — are built using the basic Newtonian design.

**Newton’s Scientific Legacy Laid the Groundwork for Modern Technological Marvels**

Newton’s discoveries laid a foundation for many of the modern technological marvels that we take for granted today. A world where Newton did not exist would look very different from our own. We might very well be centuries behind in our current status of understanding in the fields of physics, optics, chemistry and other disciplines.

For example, air travel and space exploration would likely not exist without the work of Newton. Flight of any kind requires a keen understanding of gravity, forces, inertia and momentum.

Space programs, in particular, rely on their understanding of parabolic launch trajectories and orbital mechanics. That understanding allows spacecraft to be placed in the right altitudes, at the right speeds, and with the right directions of travel for stable orbits around the Earth as well as other celestial bodies. Indeed, Newton’s work also opened the door for us to send space missions to other planets and moons in our solar system.

If Newton had not come along to make these key discoveries, someone else might have done it later. But the question is: How much later? How much further behind would humanity be in technological progress if this prodigy had not made the leaps that he did when he did? I, for one, am grateful for Newton’s brilliance and the benefits of it that we all enjoy today.

**About the Author**

*Dr. Gary Deel is a Faculty Director with the School of Business at American Military University. He holds a J.D. in Law and a Ph.D. in Hospitality/Business Management. Gary teaches human resources and employment law classes for American Military University, the University of Central Florida, Colorado State University and others. *