Recent content by sorce

  1. S

    Graduate Orbit of planet have to be a conic section

    i saw in wikipedia that Newton prove it usinge geometry in his book "principia" but i can't find download of the book/
  2. S

    Graduate Orbit of planet have to be a conic section

    How we can prove (using geomtry and not differential equation) that the orbit of planet have to be a conic section.