Parallel manipulator usually more limited in the workspace; for instance, they generally cannot reach around obstacles. The calculations involved in performing a desired manipulation (forward kinematics) are also usually more difficult and can lead to multiple solutions. Two examples of popular parallel robots are the Stewart platform and the Delta robot. Parallel manipulator A parallel manipulator is a mechanical system that uses several computer-controlled serial chains to support a single platform, or end-effector. Perhaps, the best known parallel manipulator is formed from six linear actuators that support a movable base for devices such as flight simulators. This device is called a Stewart
Parallel universes in fiction or unintentionally – as in "Angel Heart". Less often, the alternative narratives are given equal weight in the story, making them truly alternative universes, such as in the German film "Run Lola Run", the short-lived British West End musical "Our House" and the British film "Sliding Doors". More recent films that have explicitly explored parallel universes are: the 2000 film "The Family Man", the 2001 cult movie "Donnie Darko", which deals with what it terms a "tangent universe" that erupts from our own universe; "Super Mario Bros." (1993) has the eponymous heroes cross over into a parallel universe ruled by