Time vortex (Doctor Who)
In the science fiction television series Doctor Who, the time vortex (sometimes called the space-time vortex) is the medium that the TARDIS and other time machines (such as the vortex manipulators used by River Song and Captain Jack Harkness) travel through. It is mostly used as a kind of wormhole in time and space.
The vortex is outside normal space-time, and therefore normal rules of physics do not apply. For instance, in the vortex the equation for the relationship between energy and matter is E = mc3 (The Time Monster). In the Virgin New Adventures novel Just War by Lance Parkin, it was stated that the vortex was built by the Time Lords as a multidimensional spiral that connected all points in space and time.
The vortex is an extremely hostile environment. In the serial Planet of Giants, opening the TARDIS doors in-flight caused the First Doctor and his companions to shrink to about an inch. Also, in the Second Doctor serial The Enemy of the World, the TARDIS doors open in-flight, pulling Salamander into the space-time vortex.
In Warriors' Gate the interior of the ship is exposed to the "time winds", which age whatever they come into contact with. Time Lords appear to have some resistance to this, although unprotected travel within the vortex is still extremely dangerous and often considered fatal (Shada). In "Utopia", Captain Jack survives for a time in the vortex as he clings to the TARDIS whilst it is in flight; but afterwards he is judged to be dead by Martha Jones, only to revive due to his personal immortality.
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