## An unexpected opportunity for inspiration

## from the history of Isaac Newton.

Newton might not have been the most pleasant person on earth, but he may have shown us a way to find inspiration in these challenging times. In 1665, following an outbreak of the bubonic plague in England, Cambridge University closed its doors, forcing Newton to return home. During that time, Newton not only came up with a theory of gravity, but he also made outstanding contributions to optics and calculus, changing human history forever [2].

Perhaps someone is locked up at home right now about to revolutionize the world once again.

But, what inspired Newton’s scientific works? It was the need to understand the world around us. By discovering universal laws, Newton set the foundation upon which future generations can build. His laws were published in the legendary Principia Mathematica in 1687, and for the first time the Aristotelian ideas on the motion of objects were overthrown. Newton, through his laws, was not only able to describe the motion of celestial objects like planets and comets, but he also established once and for all that the earth was not at the center of the universe. Rather, it is orbiting along with the other planets around the sun. His work did not only affect our understanding of the solar system, his laws also helped spur the industrial revolution of the 18th and 19th centuries. Machines designed with Newtonian laws in mind are now in operation, and these very laws are the ones that enable us to get to space!

While he is considered, as Lagrange put it, one of the greatest geniuses that ever lived, his personality is considered mysterious and to some extent unpleasant. His famous controversy with Leibnitz over the discovery of calculus consumed many years of his life, with accusations coming from both sides. It is today accepted that he and Leibnitz discovered calculus independently.

His complete devotion to his studies was remarkable,

even though most of his free time was spent in Alchemy pursuits. There were large amounts of mercury found in his body after death, likely from his practices in Alchemy. Unfortunately, his work was not immediately seen for the greatness we know it is today. So perhaps, someone locked up at home right now is about to revolutionize the world once again, but we might not realize it in our lifetimes. Although Newton's theory of gravity turned out to be a limit of a larger framework, eventually discovered by Einstein in his general theory of relativity, Newton is considered to be the father of modern science and by no surprise his tomb carries the famous epitaph:

"Nature and nature's laws lay hid in night; God said "Let Newton be" and all was light."

## A Closer Look at Newton's Work

Taking a look at the Newton's preface to Principia — dated May 8th, 1686 — we are offered a window into the past. It's easy to be drawn to earlier times that appear simple in the modern age.

Newton's preface of Principia begins with a discussion of geometry and mechanics. He ascribes the right lines and circles of geometry as belonging to "mechanics". This intertwined relationship between physics and math is the way by which he writes upon a subject "not concerning manual but natural powers, and chiefly those things which relate to gravity, levity, elastic force, the resistance of fluids, and the like forces, whether attractive or impulsive". It is curious to think about what studying science must have looked like in the mid 1600's. We get a better picture of that by observing how Newton continues, "philosophers have hitherto attempted the search of Nature in vein; but I hope the principles here laid down will afford some light either to this or some truer method of philosophy" [1]. And of course, this work is the foundation for physics today.

Looking for some guidance in examining these works further? One way to begin exploring Principia Mathematica, would be to look at S. Chandrasekhar's well-known work Newton's Principia for the Common Reader, which can be partially obtained on google books. But perhaps a lighter introduction to the material, would be to follow the guidance of H. S. Mani in his article Some Elementary Examples from Newton's Principia. In this article, you can jump right into a few of Newton's proofs to better understand key topics, like circular motion and the area theorem (sweeping out equal areas in equal time). And, this article was intended for undergraduate students. So don't be shy!

I would like to end on a notable line of Newton's [1] "I heartily beg that what I have here done may be read with forbearance; and that my labors in a subject so difficult may be examined, not so much with the view to censure, as to remedy their defects." We often forget how difficult it is to present work to the public, even for those that become pillars of the greater community. Perhaps, the message is to remain humble and treat others with respect. Being part of physics is not so much an opportunity to tear others down, but rather an opportunity to explore the world around us, with help and inspiration from the greater community.

## Take care, stay safe, and remain inspired in these challenging times!

### References

[1] Newton. Principia, The Motion of Bodies. Mottes Translation Revised by Cajori. University California Press. 1962.

[2] Newton's Principia for the Common Reader by Subrahmanyan Chandrasekhar

[3] Some Elementary Examples from Newton's Principia H. S. Mani

[4] Scienceworld Wolfram. Biography on Newton.

[5] PBS. Newton.

[6] Wiki. Isaac Newton.

Author: Klaountia Pasmatsiou

PhD Candidate

Case Western Reserve University

Author: Erin Blauvelt

PhD Candidate

Lehigh University

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