TARDIS

A TARDIS, ( Time And Relative Dimensions (or Dimension) In Space), is the vessel which the Doctor and other Time Lords use to travel through space and time. The "D" in the name may stand for "dimension" or "dimensions"; depending on who is asked. Susan, the Doctor's granddaughter, coined the name TARDIS, and the name was eventually applied to all Time Lord time machines ("The Pilot Episode," "An Unearthly Child," "Lungbarrow"). However, some Time Lords, such as Castellan Spandrell and Romana have referred to the TARDIS as an "S/T capsule," with "S" presumably standing for "Space," and "T" standing for "Time." ("The Deadly Assassin," "The Pirate Planet"). The First Doctor often referred to the TARDIS simply as "the ship."

A properly piloted and working TARDIS is capable of transporting its occupants to any point in space and time. While it may, under certain circumstances, venture into other universes, generally a TARDIS is confined to travel within this one. The Doctor's TARDIS, generally referred to as the TARDIS, is a Type 40 Mark I.

Overview
The TARDIS "travels" by dematerializing (vanishing) from one point and, after traversing the space-time vortex, simply rematerializing (appearing from nothing) anywhere else. This peculiar device was one of the trademarks of the show, allowing for a great deal of versatility in setting and storytelling without a large expense in special effects. The distinctive sound of this dematerialization/rematerialization effect, a cyclic wheezing, groaning noise, was originally created in the BBC Radiophonic Workshop by Brian Hodgson running his keys along the strings of an old, gutted piano.

Power Systems
TARDISes draw their power from a variety of sources, but their primary source of power is a dimensional link to the nucleus of an artificial black hole created by the legendary Time Lord Omega. Each TARDIS's individual link, and the nucleus itself, is known as the Eye of Harmony. ("The Deadly Assassin," "Doctor Who: The TV Movie")

Type 40 and perhaps later types also have an ancillary power station, which on the Doctor's TARDIS exists in the form of an art gallery, the exhibited works apparently being converted from matter into raw energy when needed. ("The Invasion of Time") The TARDIS's architectural configuration controls, in addition to rearranging the almost infinite number of rooms inside the TARDIS, can also delete them, apparently converting them and their contents into raw energy which is then dumped into the reactor core. This action can often give the TARDIS the added thrust it may need to escape from areas of gravity strong enough to otherwise defeat the TARDIS's helm controls. ("Logopolis," "Castrovalva") Both these systems appear to act on a very sophisticated application of the energy-mass equation formulated by Albert Einstein as E=mc2, which among other things, demonstrates that energy and matter are different forms of the same substance, and one can be converted into the other.

Vital Components
Before a TARDIS is fully functional, it needs to be primed with the biological imprint from the symbiotic nuclei of a Time Lord's cells. Known as the Rassilon Imprimatur, this gives them a symbiotic link to their TARDISes and allows 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 is properly primed, however, and the imprint stored on a component (a briode nebuliser), it can be used safely by any species. ("The Two Doctors") Other elements needed for the proper functioning of the TARDIS and requiring occasional replenishment include mercury (used in its fluid links) and the rare ore Zeiton 7. ("The Daleks," "Vengeance on Varos")

The Doctor's TARDIS
The Doctor's TARDIS is an obsolete Type 40 Mark I that he borrowed "unofficially" when he departed his home planet of Gallifrey. All the other Type 40s, have long since been (officially) decommissioned and replaced by new, improved models, although the Master does possess a Mark II Type 40 TARDIS, and the Monk's TARDIS also appears to be a Type 40. The changing appearance of the primary console room over the years implies that the Doctor does upgrade the TARDIS's systems every now and then. Dialogue in "The Invisible Enemy" indicates the TARDIS is also capable of  periodically changing its own interior appearance. The TARDIS also has a secondary control room, and possibly more control rooms within its vast interior.

The Doctor's TARDIS appears from outside to be an ordinary 1950s style blue British police box (a phone booth designed for police communications). Although it is only slightly larger than a telephone box on the outside, the TARDIS is extremely large inside with a vast number of rooms and corridors. This is because the TARDIS is "dimensionally transcendental", meaning that its exterior and interior exist in separate dimensions. In The Robots of Death, the Doctor uses the analogy of how a larger cube can appear to be able to fit inside a smaller one if the larger cube is further away, yet immediately accessible at the same time. This application of transdimensional engineering was "a key Time Lord discovery."

Although it is supposed to blend inconspicuously into whatever time or environment it turns up in, it invariably shows up in the police box shape. At the time of the series' debut in 1963, the police box was still a common fixture in British cities. With some 700 in London alone, it was a logical choice for camouflaging a time machine. The concept of the police box disguise came from BBC staff writer Anthony Coburn, who re-wrote the programme's first episode from a draft by C. E. Webber. Coburn is believed to have had the idea for the time machine's external form after spotting a real police box while walking near his office on a break from writing the episode.

The idea may also have been a creative ploy by the BBC to save time and money in props, but soon became an in-joke genre convention in its own right as the old-style police box was phased out of use. The anachronism has become more pronounced since there have been very few police boxes of that style left in Britain for some considerable time.

The rationalisation for being "stuck" in the shape of a police box was attribued in the second episode of the series to a malfunction in the ship's chameleon circuit, the mechanism which is responsible for changing the outside appearance of the ship in order to fit in with its environment. Despite his considerable ingenuity in other fields and his ownership of a sonic screwdriver, the Doctor has been unable to fix this problem completely; the occasional temporary success has always been followed by a return to the status quo. Ironically, the exterior appearance of the TARDIS (despite slight changes in the prop) has become the most unchanging feature of the show over the course of its run, and the shape of the police box is now more immediately associated with the Doctor than with the police.

When announcements were made that the premiere story of Season 22 would have the Doctor finally repairing the chameleon circuit with the TARDIS's signature police box shape being abandoned, considerable uproar was heard from fans. The announcement appears to have been a publicity ploy, as the story in question, "Attack of the Cybermen," had the TARDIS assuming numerous exterior shapes inappropriate for its environment, such as a pipe organ, before finally settling back into its familiar police box form. In the Virgin Doctor Who novel Iceberg, the Doctor uses a "splinter" of the TARDIS which has the outward appearance of a jade pagoda.

The Doctor's TARDIS has at least two console rooms - the primary, white-walled, futuristic one seen most often throughout the programme's history and the secondary console room used during Season 14, which has wood panelling and a more antique feel to it, sometimes referred to by fans as the Edwardian console room. The cavernous, steampunk-inspired console room seen in the Doctor Who telemovie may be a reconfiguration of either of these rooms or another console room entirely. The main feature of the 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 have varied widely but share common details; hexagonal pedestals with controls around the periphery and a moveable column in the center that bobs rhythmically up and down when the TARDIS is in flight. The secondary console was smaller, with the controls hidden behind wooden panels, and had no central column. The entrance to the TARDIS can be locked and unlocked from the outside with a key, which the Doctor keeps on his person.

A distinctive architectural feature of the TARDIS interior is the "roundel," a circular decoration that adorns the walls of the rooms and corridors of the TARDIS, including the console room. Some roundels conceal TARDIS circuitry and devices, as seen in the serials The Wheel in Space, Logopolis, Castrovalva, Arc of Infinity and Terminus. The design of the roundels has varied throughout the show’s history, from a basic circular cut-out with black background to a photographic image printed on wall board, to translucent illuminated discs in later serials. In the Third Doctor serial The Time Monster, the interior console room of the TARDIS was dramatically altered, including the wall roundels. This new set, designed by Tim Gleeson, was disliked by producer Barry Letts who felt that the new roundels resembled washing-up bowls stuck to the wall. As it turned out, the set was damaged in storage between production blocks and had to be rebuilt, so this particular design only saw service in The Time Monster. In the aforementioned secondary console room, most of the roundels were executed in recessed wood paneling, with a few decorative ones in what appeared to be stained glass. The panelling for this set became warped during storage and it had to be abandoned in favor of the more familiar white room seen at the beginning of "The Invisible Enemy."

Because the Doctor's TARDIS is so old, it is inclined to break down. The Doctor is often seen with his head stuck in a panel carrying out maintenance of some kind or another, and he occasionally has to give it "percussive maintenance" (a good thump on the console) to get it to start working properly. Efforts to repair, control, and maintain the TARDIS were frequent plot devices throughout the show's run. This creates the amusing irony of a highly-advanced space-time machine which is at the same time an obsolete and unreliable piece of junk.

The TARDIS is possessed of telepathic circuits, although the Doctor prefers to pilot it manually. In Pyramids of Mars, its controls are said to be isomorphic, that is, only the Doctor can operate them. However, this characteristic seems to appear and disappear when dramatically convenient, and various companions have been seen to be able to operate the TARDIS and even fly it. The Time Lords are also able to pilot the TARDIS by remote control, as in "Colony In Space" and other episodes, usually, as the Doctor bitterly notes in "The Brain of Morbius," so he may take care of "some dirty work they don't want to get their lily-white hands on." In The Two Doctors the Second Doctor uses a portable Stattenheim remote control given to him by the High Council to summon his TARDIS to him. The Rani also uses a Stattenheim remote control to summon her TARDIS, though the Master's compliment to her on this point in "Mark of the Rani" indicates she developed hers before the Time Lords on Gallifrey did. The TARDIS is also vulnerable to diversion or relocation by the Guardians, Eternals, and other immensely powerful beings.

Some of the TARDIS's other functions include the Hostile Action Displacement System (HADS), which can teleport the ship a short distance away if it is attacked. ("The Krotons") The Cloister Room on the TARDIS sounds the Cloister Bell when disaster is imminent. The interior of the TARDIS also exists in a state of "Temporal Grace", which is supposed to ensure that no weapons can be used inside its environs. This last function is also inconsistent in its application, as demonstrated in "Earthshock."

At times the TARDIS also appears to have a mind of its own. It is heavily implied in the television series that the TARDIS is intelligent to a degree, and has a bond with those who travel in it (in the 1996 telemovie, the Doctor calls the TARDIS "sentimental"). These characteristics have been made more explicit in the novels and  audio plays. In the Big Finish Productions audio adventure  Omega, the Doctor meets a TARDIS which "dies" after its Time Lord master has passed away.

Other TARDISes
The Time Scathe was a TARDIS precursor developed on Gallifrey during the reign of the last Pythia, shortly before Rassilon, Omega, and the Other seized power. ("Cat's Cradle: Time's Crucible")The first true TARDISes were developed by this triumvirate. In "The Arc of Infinity" Omega has built his own TARDIS.

The Master has his own TARDIS, with at least one other kept in reserve, which are more advanced models than the Doctor's and whose chameleon circuits function perfectly. In the serial  Logopolis, the Master tricks the Doctor into materializing his TARDIS around the Master's, creating a dimensionally recursive loop. In his first encounters with the Doctor, the Master uses a Type 40 Mark II.

Other Time Lords with TARDISes include the Monk and the Rani. The War Chief provided dimensionally transcendent time machines named SIDRATs to the alien race known as the War Lords. Gallifreyan Battle TARDISes have appeared in the comic books, novels and audio plays, which fire "time torpedoes" that freeze the target in time. In The Chase and The Daleks' Master Plan, the Daleks named their time machines DARDISes.

In the Peter Cushing films of the 1960s, the Doctor's TARDIS is his own invention. While the exterior still has the familiar police box shape, the interior differs substantially from that in the television series, with no central console and the control room being shot on a black set with no walls to give the interior the appearance of being infinite in size. The interior doors differ from the exterior ones only by being white in color.

Cultural References

 * Outside of Doctor Who, the TARDIS has been immortalized in space: Asteroid 3325 was named "TARDIS" in its honour.


 * In the 1989 American movie Bill & Ted's Excellent Adventure, the two protagonists travel through in a time machine disguised as a phone booth, although it is not bigger on the inside than on the out.