Time Travel

Time travel is a classic science fiction subgenre that involves characters experiencing any disruption of the normal flow of time. The disruption can be real or perceived, as characters who are held in stasis without aging only to reawaken and find themselves "in the future" are just as likely to fall under the wide umbrella of this trope as characters who are transported instantaneously. Time travel can occur forwards, backwards, or in a loop. Variations of this trope are popular for both canon works and fanfiction.
==Types of time travel==
Time travel can largely be split up into physical time travel, mental time travel, and timeloops but (as with any trope classification) things tend to get messy and strange when one gets into the details. 
Time travel might or might not involve paradoxes, usually depending on whether the has a single timeline (wherein there is only ever one future and one past, leading to problems should the traveler, say, kill their own grandfather) or many timelines (wherein the traveler is technically killing an alternate universe version of their grandfather). Some works involve both.
===Physical time travel===
Physical time travel is any time travel where a character's mind and body both travel through time. Extra items like clothing or technology may or may not be included. In The Time Traveler's Wife, the eponymous time traveller always arrives naked and even has to have a tooth pulled because the filling won't travel with him. Time machines and time slips are popular methods of facilitating time travel, the first usually being voluntary and the latter most often being accidental. 
===Mental time travel===
Mental time travel involves only a character's mind traveling through time, most often but not always to take possession of their own younger body and redo their life, a trope often referred to as peggy sue (no relation to mary sue) after the movie Peggy Sue Got Married. 
In Stargate: Continuum, the character Ba'al travels back physically but as he is immortal and unaging he simply kills his past self and to take his own place, thus hitting most of the common mental time travel tropes instead of the physical ones. The Netflix show Travelers involves time travelers from the far future taking over the bodies of other people. 
===Timeloops===
A timeloop, like in Groundhog Day, is when a character repeats a period of time over and over again. This is most often mental time travel, as in the aforementioned movie, and usually a fairly short amount of time, such as a single 24-hour day. It's common for the traveler's goal to be fixing something that went wrong, escaping the timeloop, or both.
==History and canonical use==
The Science Fiction Citations website by Jesse Sheidlower, gives the earliest use of the term "time travel" as a 1914 philosophy paper, but also identifies the 1895 novel The Time Machine by H.G. Wells as the first to use "time traveller". This novel is also the source of the word "time machine" itself.
While Star Trek TOS provides a number of the earliest examples of canonical time travel in a television series, time travel has been a recurring theme in Star Trek franchise. 
The Flash and other DC Comics characters who possess super speed and a strong enough access to the speed force have the ability to travel through time or to alternate universes. The Flash (2014) has multiple storylines involving time travel. Legends of Tomorrow follows a team of heroes and villains who travel through time.
The Back to the Future film series has this as its basic premise.
Canonical time travel is also present in Doctor Who, Harry Potter, Dragon Ball Z, The Adventure Zone, Beforeigners, and a wide variety of other works. For a more complete list see the external TV tropes wiki entry.
The Professional Wrestling promotion CHIKARA had a member, Archibald Peck claimed he had been able to defeating and win because previous adversary's finishing maneuver, the Backfist to the Future, had actually sent him to the future, where he had bought a sports almanac and found out who would be answering his challenge. Another wrestler, Lance Steel claimed to have traveled through time in a "Time-Displaced Noble Knight" where he found a tag team partner who was also named "Lance Steel".
==Use in fan works==
:Fandom-specific pages: The Hobbit, Lois & Clark: The New Adventures of Superman
Time travel of all kinds is popular in fanfiction, especially in fandoms with source texts that already have canonical time travel of one kind or another. Many time travel fics are fix-it fics where the traveller has a second chance and attempts to fix a mistake or tragedy of the past. Other motivations (Watsonian or Doylist) include crossovers, interaction with characters the timeline wouldn't otherwise allow them to meet, or world building. 
===Physical time travel===
Intentional physical time travel in fics tend to be a fix-it on behalf of the time traveler, even if the traveler is the antagonist of the fic, in which case the plot revolves around fixing whatever it is they feel is wrong with the past, such as a loved one dying or the rise of an enemy they can't defeat in the future. From a Doylist perspective, the author might be looking to write interactions between the traveler and characters who, in the present, are long-dead, mortal enemies, too old to ship the character with comfortable, or some combination thereof. 
===Mental time travel===
In peggy sue fics, where the time traveller has a long to-do list of things they're going to get right this time, the peggy sue often comes from a grimdark, quasi- or literally post-apocalyptic timelines where everyone is dead or dying, in order to justify the character giving their timeline as a lost cause and/or to provide more angst or tension. The peggy sue character sometimes has to struggle to deal with suddenly having a child's body again, encountering long-dead loved ones, and/or faded memories of their own past that make it hard to convincingly pretend to be their own past self.
As many peggy sue fics stick to the stations of the canon (TV Tropes link) conflict in a peggy sue is often not a question of "What comes next?" but instead whether the peggy sue's future knowledge and better skills will let them succeed this time. A common plot-twist is for peggy sue fics to stick with the stations of the canon right up until a very crucial moment, at which things veer wildly off course and it's revealed that one of the peggy sue's enemies came back as well.
In mental time travel fics that aren't peggy sues, the traveller might be in someone else's body, or their own future. If they're in someone else's body there might be worry about the morals of the situation. Characters who are reincarnated into the past are sometimes considered to have time traveled.
===Timeloops===
If it's a fix-it, the timeloop is an excuse to get one crucial plot point right, in which case the timeloop might be self-inflicted by the character experiencing it. Usually it's more of a curse the character must overcome, sometimes without apparent cause. Characters often use timeloops to become more skilled, or at least knowledgeable, although they're held back by their bodies resetting so often.
Timeloops that repeat years, decades, or a character's entire life often have a lot in common with peggy sue time travel.
===Misc===
*Set right what once went wrong (Nobody dies, Fix-it)
*Meeting with an important character (ancestor in the past, descendant from the future, Alternate First Meeting, spending more time with the past self of a lost loved one)
*Character observes the same chain of events unfold, but gains new information and insight from another perspective and context
*Paradoxes
*Retrieving a useful artifact or tool
==Examples==
===Print examples===
* Star Trek: The Original Series:
** "The Once and Future Enterprise" by David S. Jennings, art by J.E. Fleming, from Archives Issue #2 Summer 1978. 13 pages.
** The Sourdani Journal, a 1983 novel by Lynda K. Roper.
** A Matter of Time by Peggy Avant in 1988.
* Space: 1999: Timetrap, a 107-page gen novel by Patricia Brimer, Stephen Eramo, Sharon Anne Hutchinson, & Darlene Palenik published in December 1977.
* Blake's 7: 
** "World Enough and Time" by Sue Bursztynski a 1991 gen fic in Issue #47 of The Chronicles
** "I am Falling" by Penny Dreadful, a 2003 groundhog day fic in Issue #69 of The Chronicles
* Man from UNCLE: The Running Out of Time Affair a 2001 gen time travel novel by Marlene Martin.
* Mixed Metaphors, a 1982 gen 104-page multifandom crossover novel.
===Physical time travel===
* The 100: Lightning Only Strikes Once by fiona_249. Clarke/Lexa fic in which Clarke is sent back in time following Lexa's death.
* Buffyverse: 
**Black Swan by Nemo the Everbeing. Angel is caught in a backlash of a spell gone wrong and emerges in a terrifying future. With the help of that universe's Wesley, he must find a way back through time to change history.
**A Stitch in Time by Rheanna and Yahtzee. Drusilla travels into the past to stop Angel from getting his soul back, and the Angel gang follow.
** Living History by Lizbeth Marcs. Some people have come a place far, far away and a time far, far ahead to ask for help on an urgent matter. The target place and time? Moscow, February 2008. The problem? They’re in Cleveland, September 2003. And that’s just the beginning of the trouble.
**Compelled - The Buffy/Angelverse Reshaped by Hotpoint; "The God-King of the Primordium decides to replay the game from an earlier level and shows the universe what an Old One with a grudge is capable of..." - series of stories in which Illyria travels back in time to before the destruction of Sunnydale and rewrites history.
* Final Fantasy VII: The Fifth Act (LJ link) by Sinnatious - takes advantage of the expanded canon of Final Fantasy VII to have Cloud from post Advent's children travel back to the time of its prequel, to fix things.
* Hanson: A Change of Grace by Sheryl and Karen. Time "weavers" pull Taylor back in time to the late 1800s so that he can right a wrong in the life of one of his ancestors.
* Harry Potter: Unravelling like the hours of light by Graziana, Hermione goes back in time and then returns. Nothing changes. Hermione finds herself in 1976 with Remus Lupin.
* The Lord of the Rings: Tempus Edax Rerum by Mirrordance. Angsty AU in which Legolas travels from the future to interfere the Fellowship's quest.
* Merlin: Post hoc, ergo propter hoc ('After this, therefore because of this.') by hitome_bore - Merlin travels back in time to make sure that Arthur grows up knowing that not all magic is evil.
* NCIS/Stargate SG1: Closed Timelike Curve by Bindingdiva. Gibbs/DiNozzo, Jack/Daniel, Gibbs/Jack/Daniel/DiNozzo (and combinations thereof). After the bombing, Gibbs never remembered his relationship with Tony until Tony is killed in a case involving a Goa'uld. Gibbs and O'Neill travel to the past to save him, creating a whole new future for all of them.
* Stargate Atlantis: Sheppard's Law by speranza. McKay/Sheppard. Rodney goes back in time to save John's life, a lot.
* Supernatural: The Hardest Word by gekizetzu. Sam/Dean fic in which Sam travels eight years into the future.
* Torchwood: Live In Infamy by livii, Jack/Tosh, Things did get worse after Pearl Harbor. AU for 1x12, Captain Jack Harkness.
* The Vampire Diaries: 
**Timeless by Hybridlovelies. Klaus/Caroline, The girls come up with a plan to send Caroline back in time to kill Klaus before he ever arrives in Mystic Falls. But it turns out their plan won't be as simple as they thought. Especially when Caroline gets stuck in the past & only has Klaus to rely on.
**Only Human by peaceful village. Klaus/Caroline, where a still human Caroline travels back in time and meets still human Klaus.
* The X-Files: The X-Files: Ascensions by Raj Sisodia. A continuing series of new X Files fan-fiction inspired by the season 4 the episode "Synchrony".
===Mental time travel===
* Buffyverse: 
**Impact by shiny silver grl. Takes place in season 3. As Darla prepares to give birth, Cordelia interferes with an attempt on Angel's life, but the consequences of her actions land her two years in the past, mere days before Doyle is to die on the Quintessa.
**Man of the World by EnigmaticBlue. Fred’s death and the return of his memories leave Wesley a desperate man. He makes a dangerous bid to make things right, only to find that he’s a stranger in a world that’s no longer familiar to him.
* Gilmore Girls: I’ve Been Here Before by La Rose Bleue. Lorelai/Luke. After waking up at Christopher’s, Lorelai wakes up again at home in a very different era of the Gilmoreverse.
* Harry Potter: 
**Backward With Purpose by Deadwoodpecker. Harry, Ron, and Ginny send themselves back in time to avoid the destruction of everything they hold dear, and the deaths of everyone they love.
** Eternal Return by Silver Pard. For the Greater Good. Harry understands this. 
** Harry Potter and the Nightmares of Futures Past by S'TarKan. The Dark Lord is defeated, but it took everything and everyone Harry ever cared about. This time, he'll do it differently.
* Marvel Cinematic Universe: If You Had This Time Again by dls. Loki/Tony Stark. Tony Stark closed his eyes in a wrecked Siberian bunker and woke up on a demolished New York street. Four years earlier. 
* Merlin: The King And His Sorcerer by tarayith. Arthur/Merlin. Merlin wakes up in Arthur's bed five times and incidentally discovers time travel along the way.
* Stargate Atlantis: Iterum by Keira Marcos. McKay/Sheppard. After losing Atlantis and living a miserable life on Earth, John and Rodney take a chance on an untested device for a second chance. 
* X-Men: First Class: 
**If Only Could by freckleon. Charles/Erik, Today is not the day that Charles' world came crumbling down. Today is two weeks earlier.
**Timeline series by Unforgotten. After Magneto of an X2-ish future succeeds in the unthinkable, Charles sends his consciousness back to 1962 to guide Erik away from the path that will lead to the genocide of the human race forty years hence. Charles knows that Erik has always loved him, and intends to use this knowledge + sex to seduce Erik away from his ideals in his youth. There's no way this well-thought-out, sensible, debugged and 100% bulletproof plan can possibly go wrong.
===Timeloops===
* A Song of Ice and Fire: All Mimsy Were the Borogroves by MoonWitch96. Melara Heatherspoon is Mad. But well, you would be too if you had the power of time-loops and memories of another life kicking it in your head.
* Gundam Wing: Time and Time Again by BarBieBoy. All the pilots but Heero are killed in an explosion; he relives the same day over and over, trying to stop it.
* Harry Potter: Getting the Hang of Thursdays by Hayseed. Time loop story in which Snape has to try to save Hermione.
* Merlin: Visited Upon The Son (A Thousand Shattered Futures Remix) by Woldy. Merlin will keep doing this until he gets it right.
* Stargate Atlantis: Stop All The Clocks by elementalv. Gen. The even darker side of time loops. Written for the "Not Dead Yet" challenge at SGA Flashfic. 
* Stargate SG1: A Million Days by Tallulah Rasa. Gen. An AU of the Groundhog Day episode, "Window of Opportunity". 
===Other===
* Hawaii Five-0: Deja Vu All Over Again by stellarmeadow, Danny Williams has a unique ability to rewind time one minute. Only sometimes intentionally, but always backwards one minute, except for one minute when he's 16 and time stops completely for everyone and everything around him, except him. After that, he's drawn to Hawaii.
* Supernatural: The Time-Traveler's Brother by gretazreta. Sam/Dean fusion with The Time Traveler's Wife.
* X-Men: First Class: Never Too Late To Be Who You Might Have Been by acetamide. Charles/Erik, Erik wakes suddenly and takes a deep breath, and realises that there is nothing.
===Thematic lists and rec sets for time travel stories===
:Multifandom:
::*Time Travel Recs by Lanta. Mainly Buffyverse, Harry Potter and Star Wars, with some other fandoms
::*Timetravel fic list by Lizeth, featuring Bleach, Final Fantasy VII, Harry Potter, Naruto and many others.
::*Recs tagged Time Travel at Fancake, a thematic reccomendation community on Dreamwidth
::*Recs tagged Time Loops at Fancake
::*Recs tagged Time Travel Fix-it at Fancake
::*The Time Traveling Community a multifandom Fanfiction.net community
:Buffyverse:
::*Huge List of Buffy/AtS Time-Travel Fics, compiled by blaze
:Harry Potter:
::*HP themed list: Time travel compiled by Painless_j (thematic list)
::*Harry sends his mind back in time to his younger self compiled by Lira
::*Time-travel of the redo type-involving other characters besides Harry compiled by talriga
:Naruto
::*Shifting Time a community on fanfiction.net for collecting Naruto time travel fanfiction recommendations
::* Naruto Time Travel Stories on fanfiction.net
::* Wynne's Naruto Time/Dimension Travel Favorites on fanfiction.net
:Stargate SG-1/Stargate Atlantis:
::*"time travel" tag at Crossroads fic index
::*"time loop" tag at Crossroads fix index
::*"time travel" tag at stargateficrec
::*SG-1 fic recs by green-grrl (has a time travel section)
:Supernatural:
::*Time Travel Sam/Dean and Sam'n'Dean fics post at LJ community sd_recs
==External Links and Resources==
===At AO3===
*Fanworks tagged "Time Travel"
*Fanworks tagged "Peggy Sue"
*Fanworks tagged "Time loop" or "Groundhog Day Loop"
*Fanworks tagged "Alternate Universe: Time Traveler's Wife"
===At TV Tropes===
*Time travel trope page
*Mental time travel trope page
*Peggy Sue trope page 
*Groundhog Day loop trope page
*Groundhog Peggy Sue trope page
*Unstuck in time trope page
===Elsewhere===
*Time Travel Fiction community on Livejournal
*Temporal Anomalies in Time Travel Movies by M.J. Young
*Time Travel on the Terminator Wiki
*Time Travel on the Science Fiction Encyclopaedia
== References ==
Category:Glossary
Category:Science Fiction Fandom Glossary