Sir Isaac Newton (1642–1727), English mathematician and natural philosopher (physicist) is arguably one of the most influential scientists of the last millennium. His discoveries on a range of subjects have ushered in a new era for scientific inquiry. Indeed, Newton’s discoveries in optics, general physics and mathematics would place him alongside such luminaries as Thomas Aquinas, Johann Gutenberg, Christopher Columbus and the Founding Fathers of the United States in terms of the impact he’s had on Western intellectual culture. It is thus no exaggeration to say that Newton paved the way for Modern Physics. The rest of this essay will flesh out this claim.

Although retrospectively, Isaac Newton’s genius and legacy are now accepted facts, there was no inkling during his early years that this was destined him. Born in Woolsthorpe, England on a Christmas Day in 1642, there were odds stacked against Newton’s survival. He was born premature and his survival was uncertain. Just prior to his birth his father had expired. Even his youth was nothing illustrious, as he even ventured briefly into managing his family farm. The turning point for Newton’s life in science came with his enrolment in Cambridge University in 1661. Here, he came under the charge of distinguished cleric and mathematician Isaac Barrow, who mentored and inspired the young man, especially in mathematics. It was under the guidance of Barrow that Newton would conceive and articulate some of the most groundbreaking scientific discoveries of the modern era.[i]

As per an autobiographical account written for his nephews, the major streams of Newton’s scientific work were all initiated during the plague years of 1665–66, when Cambridge was closed down due to an outbreak of plague and the young Newton went home for a short break. It was during this time that some of the cornerstone discoveries and inventions of modern physics came about. During this period, the inquisitive and penetrative mind of Newton started working on the laws of universal gravitation, the development of calculus, and the nature and behavior of light. The findings he made on these projects would enable him to make vital contributions to mathematics, theoretical physics, astronomy and experimental physics. Given the magnitude of some of these contributions, it is fair to say that Newton opened new vistas in these subjects and spawned the development of modern physics. In other words, he began to invent

“a set of mathematical techniques, including what we call the binomial theorem and differential calculus. He did a set of optical experiments that demonstrated that white light is composed of a mixture of all colors of the rainbow. And he theorized that the Moon is maintained in its orbit around Earth by the same force that causes heavy objects near Earth’s surface to fall to the ground–in other words, he began to think about the law of universal gravitation.”[ii]

Although there is no precise answer to the date of origin of modern physics, a strong case can be made that it started in 1647 with the publication of Isaac Newton’s Philosophie Naturalis Principia Mathematica. In recognition of the momentousness of this publication, the Encyclopedia Britannica called Newton “’the culminating figure of the scientific revolution of the l7th Century’, and describes Principia Mathematica as ‘one of the most important works in the history of modern science.’ From its inception, modem science has quite simply dominated the human mind.”[iii] The sweep and influence of Newton’s work on subsequent scientific developments can be gleaned from the list of his important works. In Philosophiae Naturalis Principia Mathematica, Newton gives a concise account of his discoveries in terrestrial and celestial mechanics, which is a cornerstone for modern physics. In it, he explicated how universal gravitation is operant upon objects on earth as well as in the celestial space. Further,

“Newton’s discoveries in optics were presented in his Opticks (1704), in which he elaborated his theory that light is composed of corpuscles, or particles. His corpuscular theory dominated optics until the early 19th century, when it was replaced by the wave theory of light. The two theories were combined in the modern quantum theory…. Among his other accomplishments were his construction (1668) of a reflecting telescope and his anticipation of the calculus of variations, founded by Gottfried Leibniz and the Bernoullis. In later years Newton considered mathematics and physics a recreation and turned much of his energy toward alchemy, theology, and history, particularly problems of chronology.”[iv]

Newton’s imposing legacy on the development of physics started to form during his own lifetime. No sooner did he publish Principia Naturalis and Optiks, his theories became topics of active discussion throughout England, especially in the intellectual circles of the Royal Society (in Britain as well as Continental Europe). Leading thinkers of the time in the fields of mathematics, physics and other sciences from Germany, France, Holland and Italy read Newton’s theories, laws and other observations made in his books and published commentaries of it. While his work was generally accepted and further researched upon in the rest of Europe, Newtonianism was rejected by the Church in some European countries as being in opposition to Church teachings. Nevertheless, it did spread far and wide, but behind closed doors through the means of ‘silent diffusion’.[v] But the powerful influence of Newton’s works could not be contained by religious institutions. One of the prominent examples

“is the Neapolitan philosopher Giuseppe Valletta, who lectured about the Principia and made his copy of it available to his friends. Despite the importance of Descartes to the French, Newton still carried the day. Voltaire made a hero of Newton. His Elemens de la philosophie de Neuton, published in 1737, was a success that rendered Newton intelligible and his work accessible, to the non-specialist. In Germany Leibniz praised Newton’s Principia, but was unhappy with Newton’s position regarding gravity. It was philosophically untenable to merely dismiss the problem of its cause. Leibniz and Newton were also to become bitter enemies over the issue of the development of the calculus. Still, Newton’s science continued to gain acceptance throughout Europe.”[vi]