Kepler's laws of planetary motion formula_16 The area enclosed by the elliptical orbit is formula_17 So the period formula_18 satisfies and the mean motion of the planet around the Sun satisfies This captures the relationship between the distance of planets from the Sun, and their orbital periods. Kepler enunciated in 1619 this third law in a laborious attempt to determine what he viewed as the "music of the spheres" according to precise laws, and express it in terms of musical notation. So it was known as the "harmonic law". Using Newton's Law of gravitation (published 1687), this relation can be found in the case of
Three Laws of Robotics Three Laws. However, the 1960s German TV series "Raumpatrouille – Die phantastischen Abenteuer des Raumschiffes Orion" ("Space Patrol – the Fantastic Adventures of Space Ship Orion") bases episode three titled ""Hüter des Gesetzes"" ("Guardians of the Law") on Asimov's Three Laws without mentioning the source. References to the Three Laws have appeared in popular music ("Robot" from Hawkwind's 1979 album "PXR5"), cinema ("Repo Man", "Aliens", ""), cartoon series ("The Simpsons"), tabletop roleplaying games (Paranoia) and webcomics ("Piled Higher and Deeper" and "Freefall"). Robby the Robot in "Forbidden Planet" (1956) has a hierarchical command structure which keeps him from harming humans,