Isaac Newton (1642–1727)

Isaac Newton was born December 25, 1642, (4 January 1643 on the Gregorian calendar, then not yet adopted in England), in Woolsthorpe, Lincolnshire. Already showing signs of an exceptional intellect –and solitary personality– in grammar school, he was admitted in June 1661 to Trinity College, Cambridge, an old and prestigious institution, but somewhat in decline at the time. Although the curriculum in Trinity then focused primarily on classical Aristotelian philosophy, on his own initiative Newton became acquainted with the Descartes' writings, which introduced him to mechanistic philosophy.

Isaac Newton image
Painting of Isaac Newton (1642–1727).
Credit: Wikipedia.

Between 1664 and 1666, Newton lay the groundwork of his theory of infinitesimal calculus, binomial expansion, laws of motion, theory of color, and theory of universal gravitation. He did so largely in isolation, and despite having to return to Woolsthorpe for nearly a year in the summer 1665 following the closure of Cambridge due to an outbreak of the plague. It is during these few years that nearly all of Newton's lifetime scientific achievements took shape. In October 1669 he was named Lucasian professor of mathematics, but in fact lectured very little in subsequent years. Shortly thereafter he designed and constructed the first reflecting telescope, which caused a sensation and led to his election to the Royal Society in January 1672.

Newton's masterpiece, his 1687 "Philosophiae Naturalis Principia Mathematica" (usually referred to simply as Principia), was composed between 1684 and 1686 and seen through publication by Edmond Halley, of cometary fame. Newton's key insight of 1666, namely that the same force of gravity felt on Earth also held the planets in their orbits around the Sun, was developed in detail therein, providing a theoretical framework for the Laws of planetary motion formulated empirically by Johannes Kepler, as well as a host of other phenomena, including the orbital paths of comets. Revised editions of the book appeared in 1713 and 1726.

Newton made numerous discoveries in the field of optics, especially with respect to light and colors. His groundbreaking studies of the dispersion of light by glass prisms were begun as early as 1665, first expounded in a short essay entitled "New Theory about Light and Colors" published in 1672, and described in full length only much later in his 1704 "Opticks". Newton's obsessive reluctance to publish his ideas or to entertain correspondence with other prominent European scientists was the chief cause of various priority disputes, the most strident and long lasting of which with his country man Robert Hooke (1635–1703) over various matter of optics and gravitation, and with Gottfried Wilhelm Leibniz (1646–1716) over the discovery of differential calculus.

From 1693 onward, Newton became increasingly involved in administrative and political affairs. In 1696 he became warden (and later master) of the Mint, a secure administrative position which provided him with a steady income. He was knighted in 1705 and presided over the Royal Society from 1703 to the end of his life. He died in Kensington on 20 March 1727, and was buried in Westminster Abbey after a state funeral.

Newton, I. 1687, Philosophiae Naturalis Principia Mathematica, trans. and ed. F. Cajori 1934, University of California Press.
Hall, A.R. 1963, Westfall, R. 1993, The Life of Isaac Newton, Cambridge University Press. From Galileo to Newton 1630–1720, Harper & Row [1981 Dover reprint], chapters 10 & 11.
Hall, A.R. 1992, Isaac Newton. Adventurer in Thought ,Cambridge University Press.
Westfall, R. 1993, The Life of Isaac Newton, Cambridge University Press.