An extraordinary genius and proficient physicist, mathematician, astronomer and alchemist, **Sir Isaac Newton **is considered to be the greatest and the most influential scientist who ever lived. One of the paramount contributors of the 17th century Scientific Revolution, he developed the principles of modern physics which he laid out in his book, ‘Philosophiae, Natrualis, Principia Mathematica’. Popularly known as Principia, the book highlighted the concepts of universal gravitation and laws of motions which remained at the forefront of science for centuries after. Furthermore, he worked on and developed the theory of color. He was the first to lay out the fact that color is an intrinsic property of light and that when reflected, scattered or transmitted, a white light decomposed into numerous colors that are visible in the spectrum or in the rainbow. He was responsible for building the first practical telescope. Newton also contributed to the study of power series, generalised the binomial theorem to non-integer exponents, and developed method for approximating the roots of a function. Apart from all the aforementioned, Newton made noteworthy and substantial contribution in the field of alchemy and theology as well. In his life, he held numerous significant positions such as serving as the Lucasian Professor of mathematics, President of the Royal Society and Warden and Master of the Mint. Thus, it wouldn’t be wrong to say that Newton, single-handedly, achieved milestones in physics that laid the groundwork for future discoveries by scientists across the globe.

**CHILDHOOD & EARLY LIFE**

>> Isaac Newton was born on 4 January 1643, in Woolsthorpe Manor, England, to Hannah Ayscough and Isaac Newton. His father died three months prior to his birth. Hannah remarried Reverend Barnabus Smith, leaving the three-year old Newton under the care of his maternal grandmother, Margery Ayscough.

>> Newton attained his preliminary education from The King’s School in Grantham, where he excelled and achieved the top-rank. He then enrolled himself as a sizar at the Trinity College, Cambridge in 1661.

>> It was during his years at the Cambridge that Newton developed an interest in physics, mathematics, optics and astronomy. Though he was taught standard curriculum, he developed an interest in advanced science and spent his time reading works of modern philosophers.

>> A plague epidemic of 1665 forced the shutdown of the college for two years, which Newton spent at his home in Woolsthorpe. However, he did not let go of his studies and continued the same privately.

>> It was during these two years of hiatus from regular studies that Newton worked on the development of his theories on calculus, optics and law of gravitation. He even discovered the generalised binomial theorem and began to develop a mathematical theory that later became infinitesimal calculus.

>> Newton contributed heavily to the field of mathematics, distinctly advancing every branch of the subject then studied. His work on fluxions or calculus was featured in the manuscript of 1666, which was later published with his mathematical papers.

>> It was his solutions to the contemporary problems in analytical geometry of drawing tangents to curves (differentiation) and defining areas bounded by curves (integration) that brought him into the limelight. Newton discovered that the problems were inverse to each other.

>> He also discovered general methods of resolving problems of curvature, through his method of fluxions and inverse method of fluxions, today known as differentiation and integration calculus. Unlike Leibniz’s usage of algebraically expressing calculus, Newton used both algebra and geometry to express the same.

>> Furthermore, Newton is credited for finding out the generalised binomial theorem. He even discovered Newton’s identities, Newton’s method and classified cubic plane curves.

>> Newton made significant contribution to the theory of finite differences and was the first to employ fractional indices and coordinate geometry to derive solutions to Diophantine equations

>> He returned to Cambridge in 1667 as a Fellow of Trinity. However, the same required him to become an ordained priest, something which he detested from due to his unconventional views.

>> Newton postponed the ordination indefinitely but could not prolong it further in 1669 when he was elected for the prestigious Lucasian Chair, an appointment for which ordination was a prerequisite. However, he secured special permission from Charles II which helped him to avoid ordination.

**PROFESSIONAL YEARS**

>> As a professor, Newton was required to serve as a tutor but his special permission gave him a privilege according to which he needed to deliver an annual course of lectures which he delivered on his work on optics.

>> Newton worked on his study of optics over a period of years, investigating about the refraction of light by a glass prism. Years of elaborate, refined and exact experiments led Newton to finally discover and conclude the fact that color is an intrinsic property of light and that light was composed of particles.

>> Newton found out that white light was a mixture of infinitely varied coloured rays that is visible in the rainbow and the spectrum. Furthermore, he determined the fact that the refraction of white light caused by a prism into a multi-coloured spectrum could be recomposed to white light using a lens and a second prism. He even dealt with the fact that white light, when refracted to form colored light, did not change its properties.

>> He concluded that colour is the result of objects interacting with already-coloured light rather than objects generating the colour themselves, which was later known as Newton’s theory of color. To prove this theory, Newton build upon a telescope in 1668, known as the Newtonian telescope.

>> Later in 1672, Newton came up with his first published work on lights, optics and color titled ‘Opticks: A treatise of the Reflections, Refractions, Inflexions and Colours of Light’. His work, however, did not please everyone at the Royal Society, including Robert Hooke with whom he shared an unpleasant relationship all through.

>> Unable to take the criticism well and denying the fact that his work had any shortcomings, Newton suffered from a nervous breakdown which further escalated after the death of his mother in 1679.

>> Newton went on to six years of hiatus during which he withdrew from all sorts of intellectual correspondence. It was during this time that Newton developed on his theory of gravitation and its effects, which he first started during the interval from Cambridge due to Plague.

>> Newton determined that there was a single force that determined the motion of Moon, the falling of an apple from a tree and the relation between a pendulum and a sling.

>> Developing on Hooke’s theory, he proved that the elliptical form of planetary orbits would result from a centripetal force inversely proportional to the square of the radius vector.

>> Encouraged to work out the problem mathematically and offered remuneration for the same, Newton began to work on his theory of mechanics and gravitation and came up with his first book on the subject, titled ‘Philosophiae, Natrualis, Principia Mathematica’ in 1687.

>> Popularly known as Principia, the first edition of the book set the foundation of the science of mechanics. Newton explained that gravitational force was responsible for controlling the motions of the celestial bodies.

>> He even came up with the three laws of motion. First, a stationary body will stay stationary unless an external force is applied to it. Second, force is equal to mass times acceleration, and a change in motion is proportional to the force applied and third, for every action, there is an equal and opposite reaction.

>> Though the publication of the work drew charges of plagiarism by Hooke, it was overruled as most scientists knew that Hooke had only theorized the idea and the proof that Principia reflected upon was the work of Newton.

**PERSONAL LIFE & LEGACY**

>> Despite having a near-to perfect professional life, Newton’s personal life was less than perfect. He suffered from bouts of insecurity and pride and even mental instability.

>> Newton spent his final years in Cranbury Park in Winchester England with his niece and her husband. He had achieved considerable popularity due to his scientific discoveries and a whole lot of money as well.

>> Newton breathed his last on March 31, 1727, in his sleep after experiencing severe pain in his abdomen. He was buried at Westminister Abbey. Posthumously, Newton was adjudged as the greatest scientist or genius who ever lived. He was even compared to the likes of Aristotle, Plato and Galileo.

>> There is a monument by the name, Newton’s monument that has been created at the north of the entrance of Westminister Abbey in his memory. It also points out the greatness of the genius scientist and pays a tribute to his scintillating discoveries.

>> For about a decade, from 1978 until 1988, an image of Newton appeared on Series D’1 banknotes issued by the Bank of England. The image showed him holding a book and having a telescope, a prism and a map of the Solar System by his side.

>> The Oxford University Museum of Natural History houses a statue of Isaac Newton, looking at an apple at his feet. Furthermore, the piazza of the British Library in London holds a large bronze statue of Newton.

**TRIVIA**

>> It is said that the falling of an apple from a tree inspired this great scientist to discover the force behind the action which eventually led to the discovery of gravitational force.

>> He published the book, ‘Philosophae Naturalis Mathematica’, which is widely regarded to be one of the important books in the history of science. In it, he described universal gravitation and the three laws of motion.