TARDIS console rooms, in any of the known configurations, is the TARDIS console that holds the instruments that control the ship's functions. The appearance of the primary TARDIS consoles has varied widely but shares common details: hexagonal pedestals with controls around the periphery, and a moveable column (or time rotor as it has been called in the original series and the 2011 episode "The Doctor's Wife") in the centre that bobs rhythmically up and down when the TARDIS is in flight, like a pump or a piston. The secondary console was first seen in season 14 (1976–77) of the original series.
Power-law fluid which if both ends of the coupling are spinning at the same (rotational) speed, the fluid viscosity is minimal, but if the ends of the coupling differ greatly in speed, the coupling fluid becomes very viscous. Such couplings have applications as a lightweight, passive mechanism for a passenger automobile to automatically switch from two-wheel drive to four-wheel drive such as when the vehicle is stuck in snow and the primary driven axle starts to spin due to loss of traction under one or both tires. Just like a Newtonian fluid in a circular pipe gives a quadratic velocity profile (see