Dimension
A dimension was a property of space, extending in a given direction, which, when combined with other dimensions of width and height and time, made up the universe. [source needed]
Properties
One billion cubic centimetres was small in terms of a dimension's size. (AUDIO: The Light at the End)
Terminology
"Dimension" was sometimes used interchangeably with "parallel universe" or "alternate timeline", [by whom?] but these were different variations of realities. [source needed] Time was popularised [by whom?] [statement unclear] as "the fourth dimension," though this was incorrect in spatial terms. [source needed]
Dimensions within the universe
N-Space had eleven dimensions. (PROSE: Parasite) Space [source needed] and time [source needed] were two of these. They combined into "spacetime". [source needed] Three of N-Space's dimensions were required to sustain life forms native to the universe such as humans and Time Lords. As the Twelfth Doctor theorised, "Perhaps [the Boneless didn't] even understand that we need[ed] three dimensions to live in." (TV: Flatline)
The First Doctor stated that the "fourth dimension" (as humans understood it) was time. (TV: An Unearthly Child) [disputed statement] Vicki Pallister later elaborated that time, even though a dimension in itself, had dimensions of its own. The Doctor even stated, in their adventure at the time, that he did not understand "this" fourth dimension. (TV: The Space Museum)
Hyperspace was another dimension. (TV: The Stones of Blood) It could be reached using a black hole, which essentially collapsed dimensions into a singularity. (TV: The Horns of Nimon)
According to one account, a TARDIS' interior existed as a separate dimension from the rest of the universe. This meant the interior didn't exist, creating temporal grace. (TV: The Hand of Fear) Another account described TARDISes as being a part of the universe; the Tenth Doctor said that his TARDIS was "the last TARDIS in the universe". (TV: Rise of the Cybermen) According to another account, the Eleventh Doctor said that the Doctor telling Mels that the TARDIS existing in a state of temporal grace was "a clever lie" to ensure that Mels didn't fire her gun. (TV: Let's Kill Hitler) Nonetheless, the Eleventh Doctor also described the huge room inside the TARDIS which was surrounded by a tiny exterior as "basically another dimension". (TV: The Vampires of Venice) The external dimensions of the Doctor's TARDIS were leeched by the Boneless, making its exterior shell smaller but keeping the interior the same size. (TV: Flatline)
A location of space called the Arc of Infinity was known as an ancient curve between dimensions. (TV: Arc of Infinity)
N-Forms were constructs created by the Patrexes that were able to cross dimensions and exist in pocket dimensions of their own. (PROSE: Damaged Goods)
The Mavora existed in only the first two dimensions, and thus they were a completely flat shape and could slide between the atoms of the universe. (COMIC: The Broken Man)
The 2Dis was able to restore three dimensions to small objects the Boneless had flattened into two dimensions and reverse the process. After the Boneless took on a 3D form in N-Space, they had the ability to "restore" dimensions as well. (TV: Flatline)
Dimensions in other universes
The Boneless originated from a "universe" with only two dimensions, although the Twelfth Doctor also mentioned a way of sending them "back to their own dimension". People in the three-dimensional universe of N-Space had theorised such a universe's existence, but according to the Doctor, "no-one could go there and prove its existence without a heck of a diet". (TV: Flatline)
Other dimensions
There were countless billions of dimensions, some of them incomprehensibly different to N-Space. Beings from these distant dimensions obeyed very different laws of physics and were (presumably) forbidden to cross into other dimensions. Nobody No-One came from a reality 45 billion dimensions away from N-Space and was composed of language and communication instead of matter and energy. (AUDIO: The Word Lord)
E-Space was a small dimension connected to N-Space by the Logopolitans in an effort to delay the death of the universe from entropy. Access was through a Charged Vacuum Emboitment. The Fourth Doctor and Romana stumbled through one such CVE. (TV: Full Circle) They found the Great Vampire hiding there. (TV: State of Decay)
According to Fenric, the Doctor trapped him in the Shadow Dimensions for seventeen centuries (TV: The Curse of Fenric) which were remnants of the pre-universe. (PROSE: The Curse of Fenric)
The Seventh Doctor claimed King Arthur's craft found in Lake Vortigern was from another dimension or parallel universe. (TV: Battlefield)
The Antiverse was a universe comprised of anti-time. Use of the Oubliette of Eternity would send people to this universe, turning them into Neverpeople. The Eighth Doctor and Romana went there looking for the remains of Rassilon. (AUDIO: Neverland)
The Divergent Universe was a universe created by Rassilon to contain the Divergence, a race that would theoretically replace the Time Lords. The Eighth Doctor went there on a self-imposed exile. (AUDIO: Zagreus)
Jason Kane spent several years in a hell dimension. It was predominately rock. Tunnelling craft tunnelled their way between habitable areas. (PROSE: The Infernal Nexus)
According to the Tenth Doctor, the Morass was a dimension where time and space had been torn apart. (COMIC: The Crimson Hand)
The bubble universe was a universe outside of N-Space which could be accessed from N-Space via a space-time rift. (TV: The Doctor's Wife)
Species from different dimensions
- Transcendental beings, who existed in the higher dimensions such as...
- The Guardians of Time
- The Chronovores
- The Eternals
- Spillagers (AUDIO: Winter for the Adept)
- Seven-dimensional Legions (PROSE: Lucifer Rising)
- Eight-dimensional Scourge (AUDIO: The Shadow of the Scourge)
- Good Daleks (AUDIO: Project Infinity)
- Neutron eaters (AUDIO: Lost Souls)
- Edgers (COMIC: On the Cards)
- The two-dimensional Boneless (TV: Flatline)
