Equations of motion when masses move according to Newton's law of gravity. In general relativity, rotational motion is described by the relativistic angular momentum tensor, including the spin tensor, which enter the equations of motion under covariant derivatives with respect to proper time. The Mathisson–Papapetrou–Dixon equations describe the motion of spinning objects moving in a gravitational field. Unlike the equations of motion for describing particle mechanics, which are systems of coupled ordinary differential equations, the analogous equations governing the dynamics of waves and fields are always partial differential equations, since the waves or fields are functions of space and time. For a particular
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,