TARDIS


 * This is a general article on a type of vessel. For discussion of the vehicle used by the Doctor, see The Doctor's TARDIS and TARDIS (disambiguation). 

A TARDIS or TT Capsule was the main kind of space-time vehicle used by the Time Lords.

Name
"TARDIS" was an acronym. Susan told Ian Chesterton and Barbara Wright that she had "made up the name 'TARDIS' from the initials" of the full name, "Time And Relative Dimension In Space". (DW: An Unearthly Child)


 * It was once indicated that she gave the Doctor the idea of the acronym when he was possibly the Other. (NA: Lungbarrow)

Although some Time Lords, like Castellan Spandrell and Romana, utilized the more generic name "TT capsule" (DW: The Deadly Assassin, The Pirate Planet), others were perfectly familiar with Susan's supposed acronym. (DW: The Three Doctors, NA: Lungbarrow, BBCR/BFA: Human Resources) Some beings on the fringes of Time Lord society, like the Sisterhood of Karn, also knew the acronym without being prompted by the Doctor or his companions. (DW: The Brain of Morbius)

There was a slight discrepancy as to the precise meaning of the acronym. Vicki pluralized the fourth word when she explained the term to Steven, making it stand for "Dimensions". (DW: The Time Meddler) This interpretation seemed to hold for a time, being used by several subsequent companions and Doctors. (DW: The Wheel in Space)

Nevertheless, the singular Dimension, may have been "more correct", as the Doctor's fifth, eighth, ninth and tenth incarnations — as well as their respective companions — consistently preferred the original, singular form, as did the Doctor's TARDIS itself when its matrix was transplanted into Idris. (DW: Frontios, Doctor Who, Rose, Smith and Jones, Turn Left, The Doctor's Wife) The "dedication plaque" in the Doctor's TARDIS referred to the ship as "Time and Relative Dimension in Space", favoring the singular form. (DW: Amy's Choice)

Flight
TARDISes usually moved through time and space by "disappearing there and reappearing here" (DW: Rose), a process known as "de- and re-materialisation". This was controlled by a unit known as the dematerialisation circuit. (DW: Terror of the Autons) They were also capable of flying through space like conventional spacecraft, but doing so for prolonged periods could result in damage to the ship. (DW: The Runaway Bride)

During flight, a distinctive grinding and whirring sound was often heard (DW: An Unearthly Child onwards). River Song once demonstrated that TARDISes were capable of materialising silently, teasing the Doctor (perhaps facetiously) that the noise was actually caused by leaving the brakes on (DW: The Time of Angels). Other, newer TARDISes, flown by other pilots (such as the Master and the Rani) were also known to make the same sound in the course of their normal operation, and the Minyans' computer recognized the sound as being associated with Time Lord ships. (DW: Underworld) The Doctor himself materialised his TARDIS more than once without making the distinctive noise. (DW: The Dalek Invasion of Earth, The Impossible Astronaut)

This sound was also made by other devices: SIDRATs, a craft similar to TARDISes used by the War Lords (DW: The War Games); a Time Lord who appeared to the Doctor (without using any visible means of transport) to warn him of the appearance of the Master (DW: Terror of the Autons); when the Time Lords provided the Doctor with a new dematerialisation circuit, it appeared on a table making this sound (since this was the part of the TARDIS which controlled its materialisations, it may have been operating under its own power) (DW: The Three Doctors); and when the Doctor modified Skagra's invisible spaceship to fly like a TARDIS, again, this sound was heard. (DW: Shada)

When a TARDIS materialised, it could sometimes result in strong wind and small tremors (enough to shake wine glasses) in the area in which it appeared. (DW: Love & Monsters, Smith and Jones, The Eleventh Hour, The Lodger, The Big Bang, TW: End of Days)

If a TARDIS materialised in a space occupied by another object, that object might appear inside the TARDIS. (DW: Bad Wolf) Once, the Doctor landed an incomplete TARDIS in his own TARDIS and on top of an Ood; the Ood was atomised. (DW: The Doctor's Wife) Conversely, a TARDIS could dematerialise while leaving its occupants behind. (DW: Blink)

If the TARDIS landed in the same space and time as another TARDIS, a Time Ram could occur, which would destroy both TARDISes, its occupants and even cause a black hole strong enough to destroy the Universe. (DW: The Time Monster). However, Time Rams could be avoided by materialising inside the other TARDIS. This act itself also had inherit dangers, including space loops. (DW:Logopolis, Space / Time).

TARDISes had trouble materialising during Time Loops (DW: The Lodger, SJA: The Wedding of Sarah Jane Smith)

Types
TARDISes were of two broad categories — exploratory and military. Of the two, TARDISes without armaments were apparently more common.

Exploratory
Most TARDISes were used for the observation of various places and times. This kind of TARDIS underwent much modification over the years. Each new model received a distinct number to differentiate it from other models. The numerical scheme was seemingly simple; the higher the number, the later the design had been produced. However, two types of numbering schemes may have been employed. The Monk called his version a "Mark 4", and the First Doctor's reaction seemed to suggest that he had a lower-numbered model. (DW: The Time Meddler) Subsequent incarnations and other Time Lords called the Doctor's TARDIS a "Type 40". (DW: The Ribos Operation) It is additionally possible that each type had several marks. Thus, both the Monk and the Doctor might have had "Type 40s", with the Monk's being a later version of a Type 40.

Whatever the case, TARDISes were generally referred to using the nomenclature Type X. For instance, the Second Doctor, while working for the Celestial Intervention Agency, was briefly assigned a Type 97 TARDIS. (PDA: World Game) The fifth incarnation of the Doctor once remarked that he should have upgraded to a Type 57 TARDIS. (DW: Warriors of the Deep) On another occasion, he noted that a Type 70 would allow him to break through a temporal distortion grid, but that his Type 40 was not cut out for such a "brute force approach". (BFA: Singularity) In his eighth incarnation, he encountered the Type 103, which appeared to be a near-human. (EDA: Alien Bodies)

By the time of the Doctor's fourth life, the entire Type 40 line had been retired from use. (DW: The Deadly Assassin) This policy ostensibly helped the Time Lords police the use of time travel by reducing the total number of TT capsules postemtially in use at a given moment in time. Policing was further assisted by ensuring that individual units of the same model had the same key. Thus the Castellan's guards were able to easily effect entry into the Doctor's TARDIS. (DW: The Invasion of Time)

Military
On more than one occasion, the Doctor encountered heavily armed battle TARDISes armed with time torpedoes, developed during his fifth incarnation or earlier. (DWM: The Stockbridge Horror, BFA: Neverland)

Features and functions

 * For basic information on TARDISes similar to the Doctor's, see Type 40.

Dimensionally transcendental
One of the key features of a TARDIS was that the interior existed in a different dimension than the exterior. The main application of this concept was that it was a different size on the inside than the out. With the exception of Iris Wildthyme and Professor Chronotis' TARDISes, this meant that they were bigger on the inside than the outside. (DW: An Unearthly Child, et al)

The Fourth Doctor once explained the phenomenon by using two boxes, one smaller than the other, and placed the larger one down and moving away from it so that the big box looked as if it could fit within the small box. He explained that if the big box could be accessed from the small box it would be bigger on the inside. Once they realized that. it was a small feat making them bigger on the inside than the outside suggested. (DW: The Robots of Death)

Chameleon circuit

 * See main article

One feature of all TARDISes was their ability to blend into their surroundings once they landed. If working properly, a chameleon circuit would assess the surroundings just before arrival and change the exterior to resemble something common to that landscape. (DW: An Unearthly Child, Rose, Boom Town) On the one occasion he got it working (since leaving London in 1963), the Doctor's chameleon circuit appeared to give him no control over the change (DW: Attack of the Cybermen). However, were the mechanism functioning correctly, it should have been possible to programme it from a keyboard on the TARDIS's main console (DW: Logopolis). Later models may have allowed greater flexibility. The Master's ability to produce an architectural column in sometimes incongruous environments like the Pharos Project or Heathrow (DW: Logopolis, Castrovalva, Time-Flight), as well as the Monk's statement that he chose to make his TARDIS look like a sarcophagus (DW: The Time Meddler), perhaps indicated that the circuits of later models could indeed be manually operated. This theory is further substantiated when the Doctor entered the Monk's TARDIS and changed its appearance from a pillar of stone to a police box identical to his own TARDIS. (DW: The Daleks' Master Plan)


 * In Logopolis, it is implied that the Doctor could select what the TARDIS would look like. He even demonstrates to Adric how he would change the TARDIS into a pyramid, if the chameleon circuit were functioning properly.

Organic machines
TARDISes were incredibly complex machines. The nature of their construction was such that they were said to be grown rather than constructed (DW: The Impossible Planet), thus simulating a biological process, though it is not clear whether this is indicative of the machine being biological in nature or simply so intricate and complex as to appear to mimic the processes of a biological entity.

Due to the level of complexity in their construction, TARDISes had a certain degree of sapience, and could take independent action, such as when the Doctor's TARDIS resurrected Grace Holloway and Chang Lee (DW: Doctor Who), or when someone looked into the heart of the TARDIS. (DW: Boom Town, The Parting of the Ways)

Conflicting evidence from various sources, such as other Time Lords and the Doctor himself, make unclear the extent the average TARDIS was alive, and whether that life extended beyond artificial sapience and into a biological existence. Some more-advanced TARDISes, such as Compassion, were fully sapient beings in their own right.

TARDISes often "mourned" the death of their Time Lord pilots, even going so far as to commit suicide by flying into a sun or hurling themselves into the Time Vortex. The Fifth Doctor claimed there was "an elephants' graveyard" of TARDISes somewhere at the end of time. (BFA: Omega, The Axis of Insanity)

Because the TARDIS displayed these organic traits, the Doctor considered his TARDIS to be alive. He talked to and stroked parts of the TARDIS when he operated it. (DW: School Reunion) He diagnosed mechanical difficulties as medical conditions like "indigestion." (DW: The Runaway Bride, Doctor Who) He once commented that a TARDIS was "more like a person." (DW: The Five Doctors) On one occasion, the Doctor's TARDIS manifested an avatar to help him fight a mental battle, taking on the forms and personas of the various companions who had ridden within it – however, this was when the Doctor was in fact unconscious and was battling within his own mind. (IDW: The Forgotten).

When Amy told him she thought he was mad for talking to a time machine, the Eleventh Doctor told her that the TARDIS could, in fact, hear him. (NSA: Night of the Humans)

When the matrix of the Doctor's TARDIS was placed inside the body of a human female, it was learned that they were in fact sentient beings with some degree of free will. As the TARDIS said in her human body, "All of my sisters are dead," This implies that all TARDISes were female. (DW: The Doctor's Wife)

Rassilon Imprimatur
Before a TARDIS was fully functional, it needed to be primed with the biological imprint from the symbiotic nuclei of a Time Lord's cells. Known as the Rassilon Imprimatur, this gave them a symbiotic link to their TARDISes and allowed them to survive the physical stresses of time travel. Without the Imprimatur, molecular disintegration would result — a safeguard against misuse of time travel — even if the TARDIS technology were copied. Once a time machine was properly primed, however, and the imprint stored on a component (a briode nebuliser), it could be used safely by any species. (DW: The Two Doctors)

Other

 * See List of TARDIS components

The Doctor's TARDIS

 * See main article

The First Doctor stole his TARDIS. (DW: The War Games) By the time of his fourth incarnation, all other Type 40s had been de-commisioned, save his. (DW: The Deadly Assassin) Following the events of the Last Great Time War, the Tenth Doctor believed that his was the last TARDIS in existence. (DW: Rise of the Cybermen)

Possessed by other renegades
The Master possessed at least two TARDISes. According to the Doctor, the Master's had a Mark II dematerialisation circuit. (DW: Terror of the Autons) The Rani, the Monk and Iris Wildthyme also had TARDISes. Iris' may have been even older than the Doctor's. (DW: Mark of the Rani, The Time Meddler, EDA: The Scarlet Empress)
 * See The Master's TARDIS, the Monk's TARDIS and Iris Wildthyme's TARDIS for more information.

Unique TARDISes
Compassion (a former member of the Remote) evolved into a TARDIS, the prototype of the sentient Type 102, the only one of that type. The first generation of mass produced sentient TARDISes was the Type 103. (EDA: The Shadows of Avalon)

Lolita evolved from a type 45 TARDIS that had previously belonged to the Master. (CP: Toy Story)

Idris and The Doctor also built the junk TARDIS out of dead TARDIS parts from the Bubble universe's junkyard. (DW: The Doctor's Wife)

Copies of TARDIS technology
During the Doctor's second incarnation, the renegade Time Lord known as the War Chief provided similar time ships named SIDRATs to the War Lords to further their plans of conquest. When they learned of this, the Time Lords placed the War Lords' planet in a time loop. (DW: The War Games)

When the Skith probed the Doctor's mind they gained knowledge of the TARDIS and made their own version, the SKARDIS. (DWM: The Age of Ice)

When the Daleks gained time travel, they made a version of the TARDIS, the Dalek time machine. (DW: The Chase)

An alternate reality UNIT, under the command of Rose Tyler, used technology taken from the Doctor's dying TARDIS to create a time machine to send the alternate Donna Noble back in time to correct history. (DW: Turn Left)

79B Aickman Road was a copy of TARDIS technology. (DW: The Lodger)

Behind the scenes

 * Although TARDIS is correctly spelled in all-caps as an initialism, it is common for it to appear as Tardis in novelisations and original novels, TV listings, media reports, etc. In dialogue, the word is almost always used in the context of "the TARDIS" (referring to the Doctor's capsule) or "a TARDIS". An exception to this is the two Peter Cushing films, in which it is simply referred to as "Tardis" (with the lower-case implied).
 * On the sets of the TARDIS for Christopher Eccleston, David Tennant and Matt Smith, there is a plaque saying the make model and chasis number of the TARDIS.