Isaac Newton
At his birth on Christmas day, 1642, inWoolsthorpe, Lincolnshire, Newton 'ny and frail that he was not to live. Yet despite his boyilty, he lived to the age of 85.As a delicate child, he was a loner, interested more in reading, solving atical problems, and mechaniering than in taking part in the boyish activities.
Up to the time Newton entered Cambridge University in 1661, there was lilttle inkling of his mental prowess. His shyness kept him from making easily, and he did not mix with his more boisterous fellow students. At the university he took courses in Latin, Greek, Hebrew, logic, geometry, and trigonometry, and he attended lectures in astronomy, natural philosophy, and optics. His leisure time was spent reading works by Kepler and by Descartes, the inventor of analytic geometry, and filling his notebooks with remarks on the refraction of light, the grinding of lenses, and the extraction of roots of algebraic equations.
Newton received his BA degreewithout any great distinction-and then returned to his home because of the Great Plague that was sweeping Europe. Practically all his time in his early twenties was spent at his home in Woolsthorpe. These were the most productive years of his life. During this period he discovered the expansion of the general binomial (a + b}n; he invented the "fluxions" (differential calculus); with prisms he demonstrated the composite nature of white light; he discovered the law of gravitation; and he laid the foundations of celestial mechanics.
In 1668 Newton constructed the world's first reflecting telescope. It had an aperture of 1 inch and a tube length of 6 inches, which led Newton to say of it: "This small instrument, though in itself· contemptible, may yet be looked upon as the epitome of what may be done this way." Not satisfied with his fi rst effort, he completed an improved and somewhat larger reflector with an aperture of nearly 2 inches.
The publication of his Principia (1687), embodying his mathematical principles and his ideas on gravitation and the system of the world, marked the peak of Newton's creative career in science. The Principia represents the thought and study of more than 20 years, and it ranks in importance with Ptolemy's Almagest and Copernicus's De Revolutionibus. His treatise Opticks appeared in 1704, but most of it was written many years earlier.
Many tributes followed Newton's death in 1727. One that stands out was made by the great French mathematical astronomer Lagrange, who said: "Newton was the greatest genius who ever lived, and the most fortunate; for we cannot find more than once a system of the world to establish." Newton himself acknowledged: "If I have seen further than other men, it is because I have stood upon the shoulders of giants
