Gottfried Kirch, his wife Maria, and their calendars

Although he did not travel, Newton sat at the centre of an intellectual community that stretched from India to America, though its members were all European, and Newton noted their nationality, provided that they were English. Gottfried Kirch (1639-1710), the son of a cobbler or tailor who came to Germany as a penniless refugee fromContinue reading “Gottfried Kirch, his wife Maria, and their calendars”

Newton’s inverse square law

One of the most famous results in The Principia is the theorem that states that if a body is acted on solely by a force that attracts to a fixed point, and obeys the inverse square law, its orbit is a conic. And that, conversely, if a body that is acted on solely by aContinue reading “Newton’s inverse square law”