Temporal Paradox: Difference between revisions

[[File:ParadoxWomanJ2 931.jpg|frame|[[Futurama|Torn From Tomorrow's Headlines!]]]]

 

 

A contradiction of causality within the timeline brought about by [[Time Travel]]. Theorized to be [[Time Crash|dangerous to the fabric of reality]], and known to be [[Your Head Asplode|dangerous to the brains]] of anyone who tries to get their head around them. [[Bellisario's Maxim|So don't]]. It's usually what [[The Professor]] worries about during a [[Time Travel]] story.

 

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* Toriyama follows the multiverse approach in ''[[Dragonball Z]]'': Future Trunks travels back in time to change the past, although he knows that this will not affect his own past or future (since each timeline exists as a separate dimension, changes made in one time line will not affect the others). Because Cell was also traveling around, but then Trunks prevents Cell's trip, fans have theorized that there are at least five time lines: the time line chronicled by the anime and manga (Line 1), the time line Trunks-who-participates-in-the-Cell-Games (this is Future Trunks, mentioned above) originates from (Line 2), and the time line Cell-who-killed-Trunks-to-steal-the-time-machine-and-terrorized-the-main-series-time-line originates from (Line 3), plus two theoretical/implied time lines. The first implied time line is the one visited by the Trunks native to Line 3, the Trunks killed by Cell so that he could go back to Line 1. This time line would proceed identically as Line 1 up to the point of Cell's discovery; after that, all fans have been able to guess is that the androids were somehow defeated. The commonly-accepted (suggested by the Daizenshuu guidebooks) theory is that Bulma built the deactivation switch (just like she did in Line 1) but Kuririn didn't destroy it, and Trunks took it back to Line 3 to use on the androids there. (Of course, it was the very discovery of Cell that lead Trunks and Kuririn back to Dr. Gero's lab in order to get the blueprints Bulma used to build the switch... so maybe Piccolo defeated them...?) The ''other'' theoretical time line is one Cell ''would'' have visited, if the Trunks native to Line 2 didn't kill him, using the strength gained from his training in Line 1. This line would proceed identically to Line 1 up until Cell's discovery, as well, so the Trunks visiting this time line probably won't be strong enough to defeat Cell, if he comes from a time line where Cell is waiting to kill him if he kills the androids and...

* ''[[Haruhi Suzumiya]]'': Every instance of time travel in the stories (and there are many) invariably generates paradoxes like these. Characters go back in time to save themselves, information comes out of nowhere, etc., etc. Of course, no explanation is ever given in the books.

 

 

* The [[Marvel Universe]] has a simple solution for this in the novel trilogy ''Time's Arrow''. There are a large—but not ''infinite''—number of alternate universes, that deal with what ifs. If someone in those timelines goes back in time to change something, it will create a new timeline that's an offshoot of one's own from that point. No going back and killing Hitler, Cyclops notes when told this—the idea being that if you do so, your ''own'' timeline will be unaffected. Oddly, this doesn't seem to be the case in the comic universe.

** Except when it is that way. You don't think that any two comic writers actually agree on how this stuff works, do you? That said, the ''[[Earth X]]'' series (including Universe X and Paradise X) suggests a couple of different versions of this. In the end, it is fundamentally, philosophically important that the idea that {{spoiler|alternate universes branch off only as a result of time travel}} is true.

 

 

* Pretty much every film in the [[Planet of the Apes]] franchise.

* In the ''[[Back to The Future]]'' movies, Doc Brown is very concerned with paradoxes. Paradoxen. Paradoci? [PARADOCES]

 

 

* Lazarus Long, protagonist of Robert Heinlein's ''[[Time Enough for Love]]'' creates a time machine and argues that it would not be possible for him to change the past, because in doing so he would also change the future—in the essence, negating his own existence, or at least the details of it—and making his own journey into the past improbable at best, if not impossible.

* [[David Weber]]'s ''[[The Apocalypse Troll]]'' has the characters discussing the theories about time travel—one (it's not possible) has been disproved by the fact that one character just did, to arrive in the time of the discussion; the other two, that the future will be altered by what she did or that her presence has caused an alternate world to split off, can't be proved or disproved by anything they can do now. They end up assuming the alternate world and thereafter ignore the question.

* In ''[[The Dark Tower/The Drawing of the Three|The Dark Tower]],'' Roland kills the man who murdered Jake, who Roland met in [[The Dark Tower/The Gunslinger|The Dark Tower]]. He spends the first part of [[The Dark Tower/The Waste Lands|The Dark Tower]] fighting off insanity because of the paradox this creates.

** To say nothing about what happens to Jake in the first part of [[The Dark Tower/The Waste Lands|The Dark Tower]] who is both alive and dead at the same time.

* Time travel is forbidden in [[The Dresden Files]] because it might end up destroying the fabric of reality. Characters capable of seeing the future can't be specific about their visions for the same reason.

** The Gatekeeper, specifically, has a vision of something major in the Dresdenverse, and alerts Harry to it, in the most vague, roundabout way. Bob later explains he did this to avoid the entire universe going kaput. He also mentions that no one has ever caused a temporal paradox before, and you can tell by the way the universe keeps existing.

 

 

* In ''[[Quantum Leap]]'', it appears that Sam is affected by the changes he makes to history only after he leaps, and this has some bearing on his occasional manifestation of [[Suddenly Always Knew That|previously unmentioned skills]] (and previously unmentioned/nonexistent family members). Al, on the other hand, seems to be affected instantly, but only when probability of a new event becomes sufficiently high. (In one episode, Sam assures Al's untimely death. When the probability reaches 100%, Al is replaced by another character, but he reappears when Sam reduces the probability.)

* One has to give credit to ''[[Doctor Who]]'', in that a show with a ''time traveler'' as a central character delves into temporal paradoxes relatively infrequently; in most cases, the time travelling is just a way to set stories in different periods, the temporal version of [[Adventure Towns]]. It does have its fair share of 'em though (especially after Steven Moffat started writing for the new series):

 

 

* In the RPG ''[[Feng Shui]]'' there are no temporal paradoxes, because history rewrites itself to accommodate changes in the timeline. For instance, if Donald Fong goes back in time and kills his great-great-grandfather, when he returns to the present, he'll find that everyone now knows him as Donald ''Wong'', a person with a very similar life to Donald Fong. He'll remember his old life as Donald Fong, but everyone else will always have known him as Donald Wong. In extreme cases - such as when someone controls enough feng shui sites to cause a critical shift (i.e. they change reality) - people can get written out of the timeline entirely; they still exist, but they have no past in the current timeline, because their version of history simply doesn't exist anymore.

* The german RPG ''[[The Dark Eye]]'' takes a similar approach in declaring the time a dynamic, "healing" weave. An example to solve the grandfather paradox is to have the person get stranded in time, get a life, meet a woman, marry and have kids and thus becoming his own grandfather.

 

 

* In ''[[Achron]]'' paradoxes are a deterministic and fully logical gameplay element. So pretty much a Aversion on the illogical/indefinite portion of the trope.

* The ''[[Metal Gear Solid]]'' games are well known for situations occuring in which the player can create a paradox of sorts, by killing someone in a prequel who is known to be alive in chronologically later games. Of particular note is Revolver Ocelot, in the third game, whose death during certain scenes results in an instant [[Nonstandard Game Over]]. It's especially surreal when your CO ''from the future'' starts chewing you out for causing a Time Paradox. The fact that EVA (who is never mentioned in any other game in the series AFAIK) is protected by a similar [[Nonstandard Game Over]] adds an additional layer of surreality.

** Which takes us to the third game. {{spoiler|Arriving at Babylon they find the place ransacked because by retconning his past the vizier of course never died, got hold of the dagger, and proceeded to attack it, looking for the Sands of Time. Kaileena is captured, but when the Prince tries to rescue her the vizier stabs himself with the dagger, turning into a sand god or something, killing Kaileena and infecting the Prince with the sands. Princey manages to swipe the dagger though, escape, and sets about to kill the vizier again. Along the way he bumps into Farah, who had been captured way back when the vizier got the dagger, and discovers that the sands have manifested within him as the Dark prince; a seperate personality that tries to convince him to look out only for himself. He catches up with the vizier, is soundly beaten and thrown into a well, finds his father, who is dead again, and has a crisis moment where the Dark Prince tries to take over. He resists, fights the vizier again, kills him with the dagger, Kaileena appears and cleanses him of the sands, and all seems well. Then the Dark prince pulls him into his own mind, tries to screw it all up but he resists, gets rid of him too and gets the girl. Alls well that ends well. Aside from the dead father and ruined city.}}

* The flash game [http://www.kongregate.com/games/Scarybug/chronotron chronotron] revolves around the players ability to travel back to the begining of the stage (so that multiple version of the player exists at the same time). It is quite possible to either kill a past self, or bar their passage to the time machine - resulting in a time paradox "death", complete with a [[wikipedia:Penrose triangle|penrose triangle]] warning sign.

 

 

* The actual ''objective'' of Servant Archer{{spoiler|/Heroic Spirit Emiya}} in ''[[Fate/stay night]]''. {{spoiler|He tries to kill his younger self (the protagonist, Emiya Shirou) to force a contradiction within Gaia, which he hopes will cause his whole existence to be erased to keep reality from breaking from the impossibility of the event. He himself admits that this would have a very low chance of happening, considering that by meeting Archer, Shirou is already set on ''not'' becoming Heroic Spirit Emiya, so the death of a "different" Emiya Shirou shouldn't affect Heroic Spirit Emiya in the slightest.}}

** Besides, {{spoiler|it's said that the Heroic Spirits are removed from the time axis and await their summonings in the Seat of Heroic Spirits. So, even in the case that Shirou actually ''did'' want to become a Heroic Spirit, as Archer is no longer bound by the rules of time, Shirou's death would not form a paradox and free him from his destiny. Archer's whole objective in UBW was both attempt this plan anyway in the off-chance that it actually succeeded, and to make sure his past self didn't have to see his ideals betray him like he did.}}

 

 

* Paradox is notably averted in ''[[Schlock Mercenary]]'', where it's put forth that causality is ''never'' sacrificed. If a time traveler were to go back and kill his/her grandfather, even though another one of them wouldn't be born as a result, they've already caused the event, so they'll still exist. Changes due to time travel are likened to "overwriting" the original timeline (though it's also worth mentioning that, within the Schlockiverse, time travel is normally impossible).

** The comic itself likens it to the most common time travel power in video games: [[Save Scumming|"Load Game"]].

 

 

* The ''[[Danny Phantom]]'' [[Made for TV Movie|movie]] ''The Ultimate Enemy'' is one big temporal paradox. In the original timeline, Danny's family and friends are killed, he goes mad with grief and kills himself (people with a [[Split Personality]] can do that and survive), and his [[Super-Powered Evil Side|evil self]] terrorizes the world for ten years. Thanks to Danny and some timely interference by the [[Dungeon Master]], this timeline was erased, but his evil self was in the past when it was erased, so he still exists even with the events that caused his existence never happening. His evil self even pointed out the paradox. "Don't you get it? ''I'' still exist. That means ''you'' still turn into me." The Observants mention something about him still being there because "he exists outside of time."

* Naturally enough, the animated series of ''[[Bill and Teds Excellent Adventure]]'' often courted this trope. One obvious example is the episode in which Bill and Ted neglect to buy Bill's father an antique railroad watch as a birthday present, to replace the one he lost as a child. Ted's initial plan is actually perfectly sound: [[Stable Time Loop|take the original watch from Bill's father when he 'loses' it in the past, then give it to him in the present.]] This plan fails however, so they travel even further back in time to obtain the watch ''before'' Bill's father inherits it. Of course, this should mean that Bill's father wouldn't miss the watch in the first place, but the episode [[Bellisario's Maxim|simply ignores this.]]

*** No, the ''real'' question is: Why does the Legion of Doom use [[Time Travel]] for such petty activities as foiling the origins of 3 of their 11 nemeses, or stealing a few ancient trinkets? That's like using a tactical nuclear weapon to open a can of peas.

 

** Don't forget the information paradox with the knowledge of Mikuru's mole. Kyon didn't know Mikuru had the star-shaped mole until future!Mikuru showed it to him. Mikuru herself didn't know until Kyon told her about it. When future!Mikuru realizes this, she is understandably upset, thinking she messed something up.

* ''[[Transformers Armada]]'', in the "Drift" episode. Starscream is blasted with the Requiem Blaster, then Highwire somehow apparently warps the kids back in time, but in an [[Alternate Universe]], where both the Autobots and Decepticons are imprisoned and slowly being digested within Unicron. Before he expires, Hot Shot reveals that the Minicons are actually Unicron's cells, and the Transformers were being used by them. Then the kids travel further back in time to when the Minicons were created. Here they tell them to escape from Cybertron, eventually resulting in them coming to Earth and all subsequent events in the story. Then, back in the present, Perceptor stops Thrust from blasting Starscream. Therefore, the kids had to go back in time to trigger the sequence of events that led them to Cybertron and ultimately the time travel event itself.

* In [[Dragon Ball|The Bardock TV Special]] Bardock attempts to stop Freeza from destroying Planet Vegeta to prevent the creation of a Super Saiyan. {{spoiler|He fails.}} In the Episode of Bardock spinoff it turns out that Bardock {{spoiler|wasn't killed in the explosion but was sent back in time to before the Saiyans discovered Planet Plant.}} He fights Chilled, {{spoiler|Freeza's ancestor}}, and during the fight he {{spoiler|becomes a Super Saiyan.}} This means that Bardock {{spoiler|is the Super Saiyan of legend, and that Chilled was the one who passed the legend down to King Cold and Freeza.}} That in turn means that {{spoiler|Freeza destroyed Planet Vegeta because Bardock became a Super Saiyan when he fought Chilled.}}

** What's more is that Freeza {{spoiler|ordered Dodoria to kill Bardock }}{{spoiler|[[You Can't Fight Fate|specifically because]]}} {{spoiler|he feared Bardock may}} {{spoiler|[[Self-Fulfilling Prophecy|become a Super Saiyan...]]}}

 

* [[Booster Gold]] only becomes Booster Gold because as Michael Carter, a janitor in a 25th-century superhero museum, he steals a timesphere belonging to the time master Rip Hunter. It later transpires that {{spoiler|Booster will father Rip Hunter and teach him everything he knows about time travel}}. So if he hadn't stolen the timesphere, the timesphere wouldn't have been there to steal in the first place. Augh.

** To complicate matters, {{spoiler|Rip has to train Booster to be a time master so that Booster can have trained ''him'' to be one when he was a little boy.}}

* In [[Pre Crisis]] [[Superman]] comics, all time travel works this way, which is why Superman's ability to time travel by exceeding the speed of light is not a [[Game Breaker]]; he can travel back to the past, but he can't successfully change anything. [[The Movie]] ignores this.

 

 

* Another [[Sandra Bullock]] film, ''Premonition'', [[Playing with a Trope|mixes this trope]] with [[You Can't Fight Fate]]: {{spoiler|Linda's attempts to prevent her husband's death cause it, but she does get pregnant before he dies, and prevents herself from going crazy and getting committed,}} which she could not have done had she not had the premonitions of the future.

* Referenced in ''[[Déjà Vu (film)|Deja Vu]]'' by agent Carlin right before they send a note back in time:

* Willow contains a predestination paradox (if you assume, as the film does, that prophecy really is knowledge of the future): Bavmorda's attempts to destroy Elora are the very thing that causes her own destruction, which she would not have attempted to do EXCEPT for foreknowledge that Elora was going to cause her destruction.

 

* As ''[[Lost]]'' season 5 deals with a [[Stable Time Loop]], this type of paradox is emerging. Kate, Sawyer, and Juliet save Ben's life, allowing Ben to grow up and turn the wheel, which causes the time travel in the first place. There may be physical examples as well: in the future, Richard gives Locke a compass. Then Locke travels to 1954 and gives it back to Richard. While it's possible Richard now has two compasses (and must later give Locke the "newer" one,) or the compass was never created.

** The other major season 5 storyline has a similar problem. Jack's goal is to set off a bomb that will prevent their plane from crashing, meaning they'll never come to the island; completely erasing everything that's happened on the show. This means Jack will never have been there to detonate it. Interestingly, it is suggested that the explosion may end up doing the opposite of what Jack wants and leads to the plane crashing. The blast ends up creating {{spoiler|an alternate timeline where they never went to the island.}}

* A ''Reverse Grandfather'' paradox occurs in the [[Farscape]] episode ''Kansas'': In order to convince his dad to not go on the ''Challenger'' mission, Crichton sets up a scenario he remembers from his childhood where he was trapped in a burning building and his dad saved him. When the time for the rescue actually occurs, Dad gets injured and older John has to save both his father and his younger self.

 

* Chronos, the Incarnation of Time from Piers Anthony's [[Incarnations of Immortality]] is immune to this, to an extent. He cannot be balked by paradox, he remembers the original and the new timeline, though no one else does. The limit is that he cannot interfere with his own workings ( the "Three Person Limit" ). He can exist once, go back in time and change things, but he cannot go back in time and stop himself from changing things, thus the three person limit.

* The ultimate time paradox story is [[Robert A. Heinlein|Heinlein]]'s ''--[[All You Zombies]]--'', {{spoiler|in which the protagonist turns out to be hisheritthey's own mother, father, son, daughter, grandmother, grandfather, grandson, granddaughter, great-grandmother, great-grandfather, great-grandson, great-granddaughter, great-great-grandmother, great-great-grandfather, and so on, ad infinitum.}}

* Averted—by the characters, no less—in [[Isaac Asimov]]'s short story ''The Red Queen's Race''. They wind up creating a [[Stable Time Loop]] instead. {{spoiler|A scientist conducts an experiment to send modern scientific texts back in time, translated into ancient Greek. His translator, fearing a Temporal Paradox, only translates the parts that would account for the oddly anachronistic scientific advances ''already in our ancient history'', like Hero's steam engine or the infamous Baghdad Battery.}}

* In ''[[Artemis Fowl]] and the Time Paradox'', {{spoiler|Opal Koboi from the past travels to the present, and possesses Artemis' mother, making her appear ill. This forces present day Artemis to travel back in time to get the cure from the past Artemis. Opal then uses Artemis returning to the present to return to a few days before the present to make Artemis' mother ill in the first place. Ironically, this is all so she can aquire the secret of time travel.}}

* Played with in the latest ''[[Thursday Next]]'' book, where they find that despite the existence of the [[Time Police|Chronoguard]], no one has actually ''invented'' time travel yet, so they assume that the technology much have been sent from the future and eventually they'll find the spot on the timeline where someone invented it to [[Stable Time Loop|close the gap]]. As one character describes it, it's like they're running the technology "off of borrowed credit." This causes trouble however, when the Chronoguard begins to realize that no one in the timeline ''ever'' invented time travel. The resulting paradox causes the system to unravel and gets rid of any further possibility of [[Time Travel]] in the series (although it seems everyone in the populace has a [[Ripple-Effect-Proof Memory]]).

** But by the nature of the series, couldn't someone just enter [[H. G. Wells]]'s novel and bring out a working time machine?

* In ''Flatterland'' (a [[Spin Offspring]] sequal to [[Flatland]]), Victoria Line and the Space Hopper end up trapped in a black hole. They're rescued by slightly older versions of themselves with a portable white hole, producing both a reverse grandfather paradox and an object loop.

 

 

* In [[Achron]], pulling one of these off yourself isn't as complicated as it sounds. Usual example: You build a chronoporter (a time teleporter) at a point in time. However, your opponent, who is further in the past than you, destroys your chronoporter. Since chronoporters are expensive and essential to most late-game tactics, you send some units back in time to defend the chronoporter. Instant ontological paradox! The chronoporter only survived because it was defended by units it would chronoport later on. Bear in mind that time travel is fully logical in Achron, so what seems like a paradox makes perfect sense in-game.

** It is also possible to make a unit [[Awesome but Impractical|literally]] become [[My Own Grandpa|its own grandparent/grandchild]].

* ''[[Strange Journey]]'' has a rather curious form of this. In the second sector, you find a group of Disir whose time-control powers have been stolen by Yggdrasil. They send you to the future to battle him, but since he's so powerful, he'll just utterly [[Curb Stomp Battle|curb stomp you]] with a hearty [[Evil Laugh]]. Moments later, as you drift into unconsciousness, another guy pops up in the battlefield and starts hitting Yggdrasil. Moments later, you return to Sector Two, and the Disir tell you the battle's now engraved in your destiny. Fast-forward to Sector Five, and you find yourself in a very familiar battlefield, with a sleeping Yggdrasil, and a destiny goddess who reminds you you have to save yourself before Yggdrasil kills you in the past...

* The issue of paradox is averted in ''[[Second Sight]]''. Throughout the game, it appears that John Vattic is coming across information pertaining to peoples deaths, and then projecting himself back through time to avert them. The finale [[The Reveal|reveals]] that {{spoiler|the parts which Vattic thought were the "present" were actually potential futures he was seeing through precognition. So he was ''predicting'' deaths which hadn't actually happened, rather than averting deaths through time travel (which would create the paradox of why he would need to travel back in the first place.}}

** Result: There are [[Stable Time Loop|an infinite number of Sedas who both do and don't Time Travel]].

** And before you even get to that, there's that whole ordeal in Queens. After the boss battle, Rando breaks the Life Sphere, intending to return 100 year to the past with La Saia so they can get married. [[Fridge Logic|Since when is Time Travel defined as a feature of the Life Sphere?]] We're left with the same problem: if Rando and La Saia get married, La Saia never commits suicide because Rando never got the Life Sphere, resulting in La Saia's ship never being sunk, which should completely remove the Shipwreck dungeon from the game, which would mean that the Turtle was never built, meaning that Toan never did anything in Queens. And without a dungeon to go to, there's no place for the Atla to end up, so the town itself was never destroyed.

* ''[[Dragon Quest V]]'' makes use of the Reverse Grandfather Paradox: you travel back time to meet your child self, who keeps a piece of [[Applied Phlebotinum]] that would prevent the world from total annihilation. You switch that piece with a fake, knowing that the [[Big Bad]] will kidnap your child self and destroy the thingie.

* An example of the Object Loop occurs while recovering the key to Karazahn in ''[[World of Warcraft]]''. The key, as found in the present, was beyond the skills of Khadgar to repair and so was taken back in time to be given to Medivh. Due to the damage suffered by the key, Medivh could not immediately repair it, instead giving the player a spare key. The key he was repairing would be given to Khadgar, to continue its trek into the future to be broken and taken back, ad nauseum.

** In this same game, Mephiles the Dark decides upon his name when Shadow addresses him by it. Mephiles then goes back 10 years and introduces himself to Shadow, who learns his name. Thus, Mephiles learns his name from Shadow and vice versa.

* The ''Journeyman Project'' series works on information paradoxes. The [[Time Police]] protagonist is only prompted to go back in time when monitoring devices report historical alterations. Thus, once his mission is completed, there was never a reason to go back in the first place. The only major loophole the series provides is the rule that anything travelling back in time while a temporal overwrite is moving forward ([[Timey-Wimey Ball|We know, we know]]) is rendered immune to causality.

** ''[[Remember 11]]'': Both Information Loop and Object Loop with Yuni's terabyte disk, which travels endlessly between 2011 and 2012 and back. [[Epileptic Trees|Possibly]] Reverse Grandfather Paradox in {{spoiler|"player's" involvement in the story, as "it" corrupts [[Dead Little Sister|Sayaka]], causing Satoru to devise a plan to summon and send it back in time, making "it" corrupt [[Dead Little Sister|Sayaka]]...}}

 

* At the climax of the Doc Gets Rad chapter of ''[[The Adventures of Dr. McNinja]]'', villain {{spoiler|Sparklelord}} is sent back in time to the moment when he originally entered from [[Another Dimension]]. This version apparently overwrites the original copy of him, but without any accumulated memories, thus condemning him to repeat the same sequence of events for eternity. So there is an infinite quantity of him entering the loop, but nothing coming out... huh? Presumably, the only reason the universe doesn't implode is that the comic runs on the [[Rule of Cool]].

* Trying to understand a complicated series of events in [[Irregular Webcomic]] seems to lead to this conclusion. Two characters are captured for [[Organ Theft]] purposes. Their future selves come to save them, but end up being captured as well. The original pair having their organs stolen survive by stealing the organs from their future selves, but eventually come across their original organs, and put those in them as well so that when their organs are stolen, only the spares are taken. [http://irregularwebcomic.net/1871.html It's all very complicated]. Of course {{spoiler|The characters end playing a part in destroying the universe by destroying the only time machine in existence instead of using it to become their future selves.}}

** For a more minor example, at one point Jade complains to John that [[Running Gag|her pumpkins keep disappearing]] so John sends her some pumpkin seeds for her birthday. However, these get sent back in time, and it is receiving that present that inspires Jade to start gardening in the first place.

** For another, we have one of John's conversations with Karkat, who is trolling him backwards through time. Karkat claims that John told him that humans hatch as slugs instead of being born, and John tells him that's completely false but thanks him for the pranking idea. Sure enough, in John's next conversation with Karkat, he tells him exactly that and Karkat believes him.

* [[SSDD]], Doctor Cook claims that he got on the Maytec board of directors using stock market information from a PDA that was accidentally sent back in time. But then he locked up the present day version of the PDA and made sure it was never sent back, he noted that the future version didn't disappear or anything.

** Also the Anarchists were prevented from stealing the ''Wildfire'' time machine and using it to build the ''Inglourious'' fifty years earlier. Unfortunately they still have it, centuries before it wasn't built.

 

* Tom Francis' [http://www.pentadact.com/index.php/2007-02-28-machine-of-death-exploded "Exploded"] uses the "information" variant. Two guys invent a machine that predicts how one can die. While one can ''postpone'' one's predicted death, one cannot avert it entirely. The invention makes both men fantastically wealthy, and miserable.

* The Reversed Grandfather Paradox is lampshaded for all it's worth in ''[[Red vs. Blue]]'' when Church is send back in time and attempts to prevent the accident that started the entire time travel problem.

** {{spoiler|Sheila killing Church because of the friendly fire setting?}} Guess who changed the default setting.

 

* In the first ''[[Futurama]]'' [[The Movie|movie]], the "paradox-free time travel" isn't quite paradox-free: {{spoiler|there remains an ontological paradox surrounding the origin of the name "Lars," as future-Fry chose that name when he realized that the injuries he sustained when Bender attempted to kill him made him Lars.}} From whence did the name come? No one knows.

** I do. {{spoiler|Fry was trying to say "Ow, my larynx", but the damage to his larynx made it sound like "Lars". The original Lars must have chosen the name at that moment. Paradox, schmarado- Oh, wait. The original Lars wouldn't have existed since without a Lars to send Fry into depression he wouldn't have gone back in ti-}} Oh, no. I've gone cross-eyed.

** The whole episode is this. Past Twilight is so bewildered and amazed by the concept of time travel that she can't shut up, and future Twilight doesn't manage to tell her what the actual thing she's supposed to be averting is before she gets sucked back to the future: all past Twilight knows is that future Twilight was from the following Tuesday. So she spends the week panicking about it, ends up with all the injuries future Twilight had when she visited, and by Monday night concludes the only way to stop whatever will happen by Tuesday from happening is to stop time. {{spoiler|So she goes to the archives, but as Tuesday morning arrives, nothing happens, but she finds the time spell and goes back in time to warn herself not to worry about the future...}}

 

** Dark's exact words are "Oh I didn't tell you my death note can also kill people in the past and I am going to write his name in it in the future to kill him in the past and stop him stealing the death note." [[Sarcasm Mode|Hope that clears up any confusion.]] It doesn't help that the flashback scenes go from "Present Day" to "Meanwhile in the Past" to "Back in the Future"

* In ''[[Megaman Star Force Orion]]'', Amaya and Taisaka decide to go back in time to prevent Kiri from making contact with the Ice Goddess Talisman. With the help of the UMA Fire, they reach the year in which Kiri is exiled from her home. Fire then brings them 2 years forward in time, and Taisaka and Amaya meet Tagekai, who reveals that Taisaka was originally a member of Tri-Clan. This causes Taisaka to break down as Amaya abandons Taisaka, soon meeting Takeshi's former self. Takeshi later reveals he has memories of everything that occurred as he was 66, as he is trapped in that age. Taisaka changes herself by telling her younger self not to fight Tagekai which causes her to become exiled. Amaya and Taisaka bring Kiri to the Omnikron Temple, and Amaya meets Eidaya, explaining everything. This creates a major time paradox, which causes the already fragile sands of time to become even more fragile. Soon Amaya returns to the past, meeting his father, who realizes that Amaya is Amaya, and he travels after him. As Amaya tries to fix things in Tri-Clan, Takeshi reveals he killed Taisaka, and Daisuke King, a Time Traveling Kamen Rider, shows up and brings Amaya to the present. He warns Amaya that Ryo is about to be killed by a Shinigami named Albano, and if this were to happen, the future would be corrupt, as Takeshi would cease to exist in the present. At the same time, Amaya's father plans to force time into 11:60 PM on December 24. Finally, Taisaka travels to the present from the past, creating a temporal corruption where memory demons overcome the present world and attempt to end the world. Time is eventually reset with the use of the Stolen Pocketwatch from the very first episode.

 

 

* ''Millennium'' concludes with a massive paradox barrelling its destructive way into the future whose time travel efforts caused it.

* Played with in ''[[Primer]]''. As one of the characters says, "The ''last'' revision is apparently the one that counts." We find characters gradually losing their worries about causality; they wind up going back in time to relive the events of that same week in their original place—apparently intending to do everything ''right'' this time. It appears that causing a paradox causes some kind of mild brain trauma to the time traveler involved. But then there's that other version of yourself that you drugged up and locked in the basement so you could replace him...

 

 

* In ''Strange Attractors'' by [[William Sleator]], almost any time travel to the past causes instability in the universe. As those instabilities add up, the entire universe can "go chaotic", essentially becoming a huge mass of paradoxes. The only noticeable effect of this is that electrical lighting flickers. In fact the timeline in the series is so fragile you can cause paradoxes by going so much as five minutes into the ''future''.

* In Ted Chiang's short story ''The Merchant and the Alchemist's Gate'', the titular gate can transport anyone exactly twenty years into the future, or twenty years back. This leads to increasingly more improbable shenanigans, starting with a [[Stable Time Loop]] involving a treasure map, and reaching its arguable peak when {{spoiler|a character's wife meets her husband's younger self in the past, takes him to the bedroom, and upon descovering his lack of the, er, skills that the husband has in the present, teaches him how to please a woman, over the course of weeks. It's also implied that the husband married her in the present because, when he saw her, she reminded him of the middle-aged woman who took his virginity.}}

 

 

* In the ''[[Star Trek]]'' [[Trek Verse|universe]], time travelers (and the writers) are generally immune to the effects of changes they make to the timeline, and can therefore find themselves in an [[Alternate Universe]] where they should not exist (as in "The City on the Edge of Forever" ([[Star Trek: The Original Series|TOS]]), "Yesterday's Enterprise" ([[Star Trek: The Next Generation|TNG]]), or "Cold Front" ([[Star Trek: Enterprise|Enterprise]])).

* ''[[Star Trek: Deep Space Nine]]'' has an episode with Chief Miles O'Brien going forward in time a few hours and then, when he feels he's about to die, sends his future self in the past to take his place and prevent the disaster.

 

 

* In the [[Time Travel]] RPG ''[[Continuum]]'', if a time traveler creates a paradox, they accumulate "frag," and if they accumulate too much, it eventually causes them to unravel. What's more, unchecked temporal paradoxes will eventually lead to the unraveling of reality itself. Much of the game centers around the players, who are part of "The Continuum" trying to fix paradoxes deliberately created by time travelers (known as "narcissists") who don't believe the official line on paradoxes, and who want to mess with the timeline for their own personal gain.

** Similarly, the expansion sourcebook (currently trapped in [[Development Hell]]) ''Narcissist'' has a different take on this—the original time traveler entered the "main" timeline's past and introduced time travel sometime around 14000 BC. Said time travel directly resulted in a [[The Singularity|singularity]] around 2500 AD, which then used its super-powerful minds and infinite resources to make ''sure'' that said time traveler never leaves our timeline (which would require a portal made out of X number of Temporal Paradoxes), and that time travelers don't cause the timeline to deviate from the history that led to the singularity. In alternate timelines away from "the swarm"—agents of the Singularity, named that because there's a lot of them, but they're disorganized idiots—paradoxes ''don't exist'': "frag" exists in the main timeline specifically due to the singularity's agents constantly trying to time-[[Mind Rape]] anyone attempting to change history.

* Averted in ''[[Genius: The Transgression]]''. As the game puts it, it turns out the universe doesn't particularly care if your grandmother gets shot and there's no shooter—barring [[Time Police|external intervention,]] you pop out of existence if you pull the trigger and the bullet hits home. This can have some interesting consequences, as the angry young lad seeking to avert a massacre in his country's history [[Ret-Gone|did not]][[I Am Your Father|discover...]]

* In ''[http://dig1000holes.wordpress.com/time-temp/ Time and Temp]'', a paradox would [[Ret-Gone]] ''[[Earthshattering Kaboom|all of existence]]''. Office temps (hence the name of the game) are used as field agents to prevent this, because they're otherwise [[Mooks|unimportant]] enough to minimize the risk of personal [[Grandfather Paradox]] - though their potential for [[Nice Job Breaking It, Hero|incompetence]] is at odds with this.

 

 

* In the RTS [[Achron]], you can use the free form time travel to create some interesting paradoxes. Apart from the Grandfather Paradox and the Ontological Paradox in many different incarnations, you can create a stable feedback loop to continuously strengthen your army. For example, if 10% of your army survive an attack, you can send these back in time to support their past selves in battle. That way, more units will survive and more units will get sent back in time. Thus, more units will survive. It can also happen the other way around, with your army getting continuously weaker, but that is much rarer and harder to spot. For example if the units you send back in time chronofrag (similar to [[Tele Frag]]) their past selves. Since all players have these abilities, results can get quite unpredictable.

* In ''[[Chrono Trigger]]'' one character accidentally paradoxes herself out of existence, forcing you to put history back on track. Later you get to do things like take an item from a treasure chest, then go back in time four hundred years and loot its (inferior) temporal duplicate.

{{quote|<To a very confused Keira>

'''Daxter:''' Honey, the more you think about it, the more it hurts the head! }}

** Mephiles hates Shadow for sealing him, and attacks when he's freed. Shadow hates Mephiles for attacking him, and seals him. What?!?

* ''[[Radiant Historia]]'' has them. Logical, since one of its central themes is [[Time Travel]]. One of the most obvious examples is {{spoiler|a mission where you talk to a grieving widow, who laments the medicine she got for her husband never arrived till it was too late, leading the party's hero to accept the medicine and give it to the man in the past, causing him to feel better, negating the need for ordering the medicine in the first place}}. Well, gosh.

 

** Well, three of the girls do not remember ever being anything ''but'' girls, so presumably their memories were altered. [[Plot Hole|As for Jo...]]

* In the Surreptitious Machinations arc of [[General Protection Fault]], Empress Trudy travels back in time to give her younger self the necessary information on what she must do to take over the world. Near the end of the arc, Nick and Ki's son Todd reveals that the entire [[Bad Future]] he and Empress Trudy came from was the product of a temporal paradox, since it could not have happened without Empress Trudy advising her younger self, which would not be possible if it did not previously exist. It is heavily implied that {{spoiler|Pandemonium}} was responsible for the existence of the alternate future in the first place. As a result of the future being changed, Todd, the Empress and all other objects from the alternate future fade from existence, but the Empress teleports to a different time just before she fades, and the Gamester finds and recruits Todd.

 

 

** Well the original timeline seems to be that 70's Cosmo is that cause of Crocker losing him and Wanda. Timmy then stops this incident only for present day Cosmo to turn on the mic while Timmy is talking and cause the incident to happen anyway. While this doesn't explain how Crocker knew about the existence of fairies after his mind was wiped in the original timeline, since we don't see the original incident play out, we can just assume any number of reasons for that. (Perhaps he managed to write a note in that timeline too)

** There was also a [[Historical In-Joke]] to imply that it was an alternate timeline.

 

{{reflist}}

[[Category:Narrative Devices]]

[[Category:Time Travel Tropes]]

[[Category:Self-Demonstrating Article]]