(2)ISAAC NEWTON 1642_ 1727

 Nature and Nature's laws lay hid in night God said, Let Newton be! And all was light. Alexander pope

Isaac Newton, the greatest and most influential scientist. Who ever lived, was born in Woolsthorpe, England, on Christmas day, 1642, the same year that Galileo died. Like Muhammad, he was born after the death of his father. As a child, he showed considerable mechanical aptitude, and was very clever with his hand. Although a bright child, he was inattentive in school and did not attract much attention. When he was a teenager, his mother took him out of school, hoping that he would became a successful farmer. Fortunately, she was persuaded that his principal talents lay elsewhere, and eighteen, he entered Cambridge University. There, he rapidly absorbed what was then knows of science and mathematics, and soon moved on to his own independent research. Between his twenty- first and twenty- seventh year, he laid the foundation for the scientific theories that subsequently revolutionized the world. The middle of seventeenth century was a period of great scientific ferment. The invention of the telescope near the beginning of the century had revolutionized the entire study of astronomy. The English philosopher Rene Descartes had both urged scientists throughout Europe to cease relying on the authority of Aristotle and to experiment and observe for themselves. What Bacon and Descartes had preached, the great Galileo had practiced. His astronomical observation, using the newly invented telescope, had revolutionized the study of astronomy, and his mechanical experiment had establish what is now know as Newton's first law of motion. Newton was always reluctant to publish his result, and although he had formulated the basic ideas behind most of his work by 1669, many of his theories were not made public until much later. The first of his discoveries to be published was his ground- breaking work on the nature of light. In a series of careful experiment, Newton had discovered that ordinary white light is mixture of all the colors of the rainbow. He has also made a careful analysis of the consequences of the laws of the reflection and refraction of light. Using these laws, he had in 1668 designed and actually built the first reflecting telescope, the type of telescope that is used in most major astronomical observatories today. Newton's most discoveries, however, were in the field of mechanics, the science of how material objects move. Galileo had discovered the first law of motion, which describes the motion of objects if they are not subjected to any exterior forces. In practice, of course, all objects are subjected to exterior forces, and the most important question in mechanics is how objects move under such circumstances. This problem was solved by Newton in his famous second law of motion, which may rightly be considered the most fundamental law of classical physics. The second law (described mathematically by the equation F = ma ) states that the acceleration of an object (i.e., the rate at which its velocity changes is equal to the net force on the object divided by the object's mass. To those first two laws, Newton added his famous third law of motion (which states that for each action _i.e., physical force _ there is an equal and opposite reaction), and the most famous of his scientific laws, the law of universal gravitation. This set of four laws, taken conjointly, form a unified system by means of which virtually all macroscopic mechanical systems, from the swinging of a pendulum to the motion of the planets in their orbits around the sun, may be investigated, and their behavior predicted. Newton did not merely state these laws of mechanics; he himself, using the mathematical tools of the calculus, showed how these fundamental laws could be applied to the solution of actual problems. Now, one might grant that Newton was by far the greatest and most influential scientist who ever lived but still ask why he should be ranked higher than such major political figures as Alexander the Great or George Washington, and ahead of such major religious figures as Jesus Christ and Gautama Buddha. My own view is that even though political changes are of significance, it is fair to say that most people in the world were living the same way 500 years after Alexander's death as their forebears had lived five centuries before his time. Similarly, in most of their daily activities, the majority of human beings were living the same way in 1500 A.D. as human beings had been living in 1500 B.C., In the last five centuries, however, with the rise of modern science, the everyday life of most human beings has been completely revolutionized. We dress differently, eat different foods, work at different jobs, and spend our leisure time a great deal differently than people did in 1500A.D. Scientific discoveries have not only revolutionized technology and economics; they have also completely changed politics, religious thinking, art, and philosophy. Few aspects of human activity have remained on changed by this scientific revolution, and it is for this reason that so many scientists and inventors are to be found on this list. Newton was not only the most brilliant of all scientist; he was also the most influential figure in the development of scientific theory, and therefore well merits a position at or near the top of any list of the world's most influential persons. Newton died in 1727, and was buried in Westminster Abbey, the first scientist to be accorded that honor.