Newton's theorem of revolving orbits does not go to infinity. However, this conclusion holds only when two bodies are present (the two-body problem); the motion of three bodies or more acting under their mutual gravitation (the "n"-body problem) remained unsolved for centuries after Newton, although solutions to a few special cases were discovered. Newton proposed that the orbits of planets about the Sun are largely elliptical because the Sun's gravitation is dominant; to first approximation, the presence of the other planets can be ignored. By analogy, the elliptical orbit of the Moon about the Earth was dominated by the Earth's gravity; to first approximation, the
Three Laws of Robotics even when ordered to do so, as such orders cause a conflict and lock-up very much in the manner of Asimov's robots. Robby is one of the first cinematic depictions of a robot with internal safeguards put in place in this fashion. Asimov was delighted with Robby and noted that Robby appeared to be programmed to follow his Three Laws. Isaac Asimov's works have been adapted for cinema several times with varying degrees of critical and commercial success. Some of the more notable attempts have involved his "Robot" stories, including the Three Laws. The film "Bicentennial Man" (1999) features Robin