An alternate timeline is a reality that diverges from the "true" timeline due to the actions of time travellers or
other temporal phenomena. They are different from a parallel universe in that they do not exist as seperate continuums.
Physics
Alternate timelines can be visited accidentally by contact with a time track (DW: The Space Museum, BFA: The Mutant Phase) or other anomalies (BFA: Colditz) in the Time Vortex. Deliberate travel to these timelines is possible if the traveller possesses something, such as the sigil ring, that allows them to change time streams. (MA: Goth Opera) Whether it is possible or not to travel to a timeline after it has been negated is unknown, though every point in time has its alternative (DW: Pyramids of Mars) and so every alternative may always exist.
They may diverge from points in history where there is temporal fluxuation, but beings with enough power are capable of changing time enough to create them, such as Sutekh and the Chronovores. Because the universe only has a finite amount of mass and energy, the creation of an alternate timeline adversely affects the real timeline, causing chaos throughout the universe; releasing enough energy can destroy the timeline and set history back on its correct course. (NA: Blood Heat) This may explain why the effects of the reality bomb (DW: Journey's End) and Rassilon's Ultimate Sanction (DW: The End of Time) could be observed before either event had even occurred.
Though a timeline may be negated, memories of it could still be retained.
Timelines encountered by the Doctor
| Timeline |
Negated By |
Featured in
|
| The First Doctor and his companions become exhibits in the Moroks' Space Museum |
First Doctor, Ian Chesterton, Barbara Wright, Vicki |
DW: The Space Museum
|
| Barbara Wright marries Ptolemy I and becomes Queen of Alexandria |
alternate Barbara |
VD: The Book of Shadows
|
| WOTAN conquers Earth (this was the correct timeline before it was changed by the Doctor) |
First Doctor |
PDA: The Time Travellers, DW: The War Machines
|
| Nancy Grover uses Grold technology to become a goddess |
Third Doctor and Liz Shaw |
MA: The Eye of the Giant
|
| The Power Elite take over Earth |
Third Doctor |
VD: Prisoners of the Sun
|
| Freedom fighters from the 22nd century assassinate Sir Reginald Styles |
Third Doctor and Jo Grant |
DW: Day of the Daleks
|
| Theodore Cassells's experiments lead to a global war which devastates Earth |
Third Doctor |
TVA: A Stitch in Time
|
| The Third Doctor dies on Dust and regenerates |
Eighth Doctor by destroying Gallifrey (EDA: The Ancestor Cell) |
EDA: Interference - Book One, Interference - Book Two
|
| Sutekh is freed and devastates Earth |
Fourth Doctor and Sarah Jane Smith |
DW: Pyramids of Mars
|
| Daleks undergo the Mutant Phase |
Dalek Emperor |
BFA: The Mutant Phase
|
| Melanicus creates the Millennium Wars |
Fifth Doctor, Sir Justin and Shayde |
DWM: The Tides of Time
|
| Humans evolve into Haemovores |
Seventh Doctor and Ace |
DW: The Curse of Fenric
|
| The Dark Matrix terrorises England |
Seventh Doctor and Ace |
PDA: Matrix
|
| The Nazis win World War II after a piece of laser technology is left at Colditz Castle |
Alternate Eighth Doctor and Elizabeth Klein (inadvertantly) |
BFA: Colditz, Klein's Story
|
| Adolf Hitler uses the Timewyrm's power to enable Nazi Germany to conquer Earth |
Seventh Doctor and Ace |
NA: Timewyrm: Exodus
|
| Chad Boyle kills Dorothy McShane with a brick to the head |
Ace |
NA: Timewyrm: Revelation
|
| The Process enslaves the Time Scaphe crew |
Seventh Doctor |
NA: Cat's Cradle: Time's Crucible
|
| Silurian Earth |
Destroyed, not negated, by Seventh Doctor |
NA: Blood Heat
|
| The Doctor doesn't leave Gallifrey, allowing many alien races to invade Earth |
Seventh Doctor, Ace and Bernice Summerfield |
DWM: Time & Time Again
|
| The Knights of Velyshaa conquer Gallifrey |
Fifth Doctor, Sixth Doctor, Seventh Doctor, the Temperon |
BFA: The Sirens of Time
|
| Humans don't evolve and Earth is a Tractis colony known as Paratractis |
Eighth Doctor, Sam Jones, Jo Grant |
EDA: Genocide
|
| Pete Tyler doesn't die and Reapers begin consuming humanity |
Pete Tyler |
DW: Father's Day
|
| The Year That Never Was |
Tenth Doctor, Martha Jones and Captain Jack Harkness |
DW: Last of the Time Lords
|
| Donna's World |
alternate Donna Noble, with assistance from Rose Tyler |
DW: Turn Left
|
| The Progenitor Daleks repopulate Skaro and exterminate humanity to extinction |
Eleventh Doctor and Amy Pond |
VG: City of the Daleks
|
| The Doctor's TARDIS explodes, creating a Time Field which erases parts of history |
Eleventh Doctor, Amy Pond, Rory Williams (Auton) and River Song (DW: The Big Bang) |
DW: Series 5
|
| Amy Pond is stranded on Apalapucia for 36 years |
Eleventh Doctor |
DW: The Girl Who Waited
|
| River Song's World |
Eleventh Doctor, Amy Pond, Rory Williams, River Song, the Teselecta |
DW: The Wedding of River Song
|
Timelines encountered by others
