TARDIS

"That's it? That's a TARDIS? The pinnacle of time technology reduced to a wooden shack with a lamp on top?"

―Hellenica Monroe

TARDIS
General Information
Other names	Time Capsule Timeship
Homeworld	Gallifrey
Sapience level	Sapient
Species origin	Created by Time Lords
Racial abilities	Spacetime traveling
Behind the Scenes
Universe	Doctor Who

TARDIS; which stands for Time and Relative Dimension in Space; is a designation coined by Susan Foreman to refer to living, intelligent, spacetime-traveling biomechanical ships, the type of which is employed by the Time Lords of planet Gallifrey to travel through time and space and traverse the time vortex. They're dimensionally transcendental and can change their physical appearance to pass off as a commonplace object.

Biology

Originally, the TARDIS designation might have applied specifically to the Doctor's vessel, but it seems to have spread out to the point of becoming the most popular name for the whole diverse class of living Gallifreyan timeships. Several different types exist, with the Doctor's TARDIS being a Type 40: generally regarded as a very outdated model by other Time Lords.

TARDISes are well known for being dimensionally transcendental, i.e. much bigger on the inside than the outside; and may in fact house their own miniature pocket universes containing numerous rooms, corridors and machinery. The Doctor's TARDIS contains a library, a zoo and a swimming pool, among other things.

A TARDIS on the planet Marinus.

The chameleon circuit allows a functioning TARDIS to rapidly scan its surroundings before it materializes into a specific time and location, and assume an illusory form that draws no attention to itself. It's also possible for the Time Lord to choose the shape his or her TARDIS will take. A fault in the chameleon circuit may cause a TARDIS to become "stuck", however, just like the Doctor's TARDIS ended up permanently stuck in the shape of a 20th century British police box.

In spite of its enormous mass (once estimated as 5 million kilos "in [Alzarius'] gravity"), a TARDIS can alter its weight to match what would be expected of the object it is disguised as; and thus can be lifted and carried away by groups of humanoids. It is, however, far more durable than what it appears to be, as the Doctor's TARDIS has remained intact after falling off a mountain, and even the army of Genghis Khan wasn't able to break into it.

A TARDIS' console room.

The TARDIS' translation circuits allow its non-Time Lord occupants to speak and comprehend most alien languages: a process that requires mediation by the TARDIS' resident Time Lord (as Time Lords already are natural polyglots thanks to their psychic abilities). Being living creatures, the relationship between a TARDIS and its Time Lord pilot is symbiotic, and a TARDIS may even assist in the Time Lord's regeneration process. When a Time Lord uses up all their 13 lives and dies permanently, their TARDIS will head back to Gallifrey to report their death.

Despite the chameleon circuit suggesting that an element of stealth would be integral to the design of a TARDIS, these ships make a very distinctive whirring sound when they materialize and dematerialize. Contrary to some belief, this sound is not exclusive to the Doctor's TARDIS, although it might possibly be a characteristic of earlier models. It is possible to materialize a TARDIS silently, however.

Notes

• Although the TARDIS acronym stands for "Time and Relative Dimension in Space", it was occasionally given as "Time and Relative Dimensions in Space" instead (notice the plural). This error has been committed even by the Doctor himself, albeit rarely.
• Romana's statement about the TARDIS weighing about 5 million kilos in Alzarius' gravity is confusing, as kilograms are not dependent on gravity. However, it's possible that the physics of E-Space (where Alzarius is located) might differ from those of normal space to the point of altering an object's mass. It's also possible that "kilos" in this case might refer to a Gallifreyan unit rather than common kilograms.
  • Alternatively, one might interpret the statement as meaning that its weight in Alzarian gravity is equivalent to the weight of 5 million kilos in "normal" (presumably Gallifreyan) gravity.
• According to Derrick J. Wyatt, the Omnitrix from the Ben 10 franchise is unable to accept TARDIS DNA, despite them being sapient beings, due to their nature as living spaceships.