ABSTRACT
In the history of science, 1666 was annus mirabilis-a miraculous year. The plague, which had reached London the preceding spring, was spreading throughout the south of England, and was only brought under control by the Great Fire twelve months later. In the meantime, Cambridge University had closed its doors and sent all its students home, among them the young Isaac Newton. At his mother’s farm at Woolsthorpe he spent a year of enforced idleness-as legend would have it, watching apples fall. But in that year he invented differential and integral calculus, he created his theory of universal gravitation, and he proved experimentally that white light is made up of many colors. When asked how he managed to do all these in so short a time, his unhelpful reply was: “By thinking about them.”
