principia – Newton's Principia: Translation, Beneath the Surface

Newton and the orbit of comets part 2

In this blog I plan to outline the method that Newton, and then Halley, used to compute the orbits of comets. It is a challenge to those who are handy with a computer, or who have the skills of draughtsmanship; and I hope that it will also be of interest to people who are interestedContinue reading “Newton and the orbit of comets part 2”

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”