5 Time Travel Paradoxes That Will Induce Headaches

[Therumancer]

Well, the other theory is of course that by time travelling you step outside of time and thus can make whatever changes you want without actually causing a paradox. Basically the universe knows you existed, and caused an event that prevented your own existence or time travel, and thus you do exist, even if the timeline no longer accounts for your existence.

This is common in a lot of science fiction, and things like the X-men used it heavily in explaining how say Bishop could travel back in time, change the past to prevent a nightmare future, and not cause a paradox as a result. The same science that sent him back in time ensured that he was effectively outside of time, and thus it doesn't even matter if he prevents his own existence.... the universe STILL knows what happened. Of course Marvel has also defined itself temporally a lot of different ways over the years and seems to largely fall back on the "Multiverse" theory which is why guys like Doctor Doom, Kang The Conqueror (actually a future descendant of Doom if I remember) and others haven't pretty much wrecked creation.

Marvel Comics still uses multiverse theory, they just flip the definition from the standard one that the article uses (popularized by Ray Bradbury, IIRC). Basically, in Marvel terms, the original timeline becomes a "parallel universe", and the new timeline is now the mainstream universe. This makes a lot more sense in a story where time travel is possible and effective, yet paradoxes are not created.

The X-Men are, as usual, the best example. Rachel, Bishop and Nimrod are all from the "Days of Future Past" universe, which continued to exist after Kitty went back in time and prevented it from happening in the main timeline. Nimrod is a Predestination Paradox (the tech from past-Nimrod is used to design future-Nimrod), while Bishop is a Grandfather Paradox (the reason he went back in time is no longer valid thanks to his own actions) and Rachel is not really a paradox at all. (She time traveled specifically to escape her own timeline, and now affects only the main timeline.)

It could be argued that Marvel uses the Multiverse theory now, it hasn't always done so. Largely because Marvel has an increasingly vested interest in keeping as many versions of it's various IPs out there as possible. I thought I mentioned that originally. There is a difference between how Bishop was originally conceived, defined, and handled, compared to where they went with it later. Especially when you look back at some of the comments made when guys like Kang have showed up from the future (he's not a moron, and the point is he's not splitting the timeline which is what made him so terrifying, but they use him increasingly less), not to mention very old Story Arcs where Spider Man hitched a ride on Doctor Doom's time machine. After all when Spidey returns to the present the last time and there is no more time travelling going on, he doesn't suddenly run into a second Spider Man. Granted there are a number of conceptually unlikely ways of dealing with that (like say every Spider Man sidestepping into another reality at that time so none of them ever meet each other) but that wasn't in the spirit of the story from what I remember. Ditto for the whole Bishop thing, where the whole point would have been rendered irrelevant if travelling back in time would have accomplished nothing (which is something Forge of all people likely would have known).

But yes, other odd Paradoxs do show up, and stories about Cable fighting Apocolypse, heavily exploit that possibility. Way back during "Contest Of Champions 2" they even had a weird match up between Cable and The Scarlet Witch which was never resolved. The Scarlet Witch fundamentally changes probabilities, while Cable travels/bodyslides through time and space to use foreknowledge to counter problems he's encountered in the past (well in his most over the top portrayals). The "match" as far as it went involved Wanda hexing, and Cable entering flux (shadows of multiple versions of him there as he ran through possibilities of beating her) as they started countering each other continually before it was interrupted. While I suppose one could argue billions of alternate realities were created right there (billions is nothing when your dealing with the infinite) I'm not buying that within the spirit of the entire thing, even when one argues the Cable is fighting Apocolypse across multiple realities at any given time.

 

[Triaed]

What bothers me and it is almost never discussed is that the atoms (whether in a time traveller's body or object) are already in use in either the future or the past by another object. We cannot create mass/energy

Yes, this could be explained by the parallel universe theory: one would arrive at a universe where exactly the number of atoms in your body would be there already... in your body.

So, if I were to travel to 100 years to the past, the atoms that make up my body, clothes, etc would be already in use by a potato, a train, some Ukrainian woman's scarf and 6 of my atoms would be part of Einstein's body (probably his balls)... apparently, we all need to have someone famous' atoms in our body today. The point is that I could not be there.

Same thing if I travel 100 years in the future. Most of the atoms that compose me today would be scattered and in use someplace else. My mass cannot occupy that space... even if I am scattered in trillions of little bits all over the world (although most likely in a pile of dirt or ash).

 

[ExtraDebit]

Imagine we made the sun travel 1 second into the past, now we got 2 suns. We could essentially duplicated anything like in diablo 1 by making it travel back in time. It fucks thermal dynamics in the face and then some. The problem with pseudoscience like time travel is that it fucked up all the proven science.

 

[WindKnight]

My personal favorite paradox is from the Robert Heinlan story 'All You Zombies' Spoilery summary, with the really big spoilers in a spoiler box

An agent for a time travel agency wants to recruit a man Known as 'the unmarried mother'(TUMM), and listens to his lifes tale - of how he was abandoned on the doorstop of an orphanage as a girl (bear with me), and as a teenager was seduced by an older man who got her pregnant and then abandoned her suddenly, with the birth revealing she had both sexual organs, and the pregnancy had ruined the female, so they set her up with the male organs. As a man he bonds with his new daughter, until the father (though described as being older than he would have been) kidnaps the baby and disappears.

The recruiter offers to help TUMM find the guy and take his revenge, taking him back in time...

Spoiler

he drops TUMM off just in time to meet a young girl, before jumping forward about a year, kidnaps the daughter, jumps back even further and drops her off at the orphanage, then jumps back to where he left TUMM to grab him, and take him to the time agency. Everyone in the story - including the recruiter - is the exact same person at different points along their timeline.

 

[Hagi]

Spoiler: How to kill Hitler without paradoxes:

 

[Rhykker]

Spoiler: How to kill Hitler without paradoxes:

I believe that is the Predestination Paradox

 

[Hagi]

Spoiler: How to kill Hitler without paradoxes:

I believe that is the Predestination Paradox

I was under the impression that the predestination paradox is a time traveller causing himself to go back in time.

As in a person as an infant getting saved by a mysterious man, causing him to live to an old age where time travel is invented. In order to find out who saved him he travels back in time, only to find an infant on the verge of death and him the only person who can save said infant.

Killing Hitler seconds before he commits suicide hardly constitutes causing your own journey, you'd have to cause Hitler to happen for that paradox to go.

 

[Rhykker]

Spoiler: How to kill Hitler without paradoxes:

I believe that is the Predestination Paradox

I was under the impression that the predestination paradox is a time traveller causing himself to go back in time.

As in a person as an infant getting saved by a mysterious man, causing him to live to an old age where time travel is invented. In order to find out who saved him he travels back in time, only to find an infant on the verge of death and him the only person who can save said infant.

Killing Hitler seconds before he commits suicide hardly constitutes causing your own journey, you'd have to cause Hitler to happen for that paradox to go.

The example you gave is an example of the predestination paradox, but the predestination paradox doesn't have to involve a time traveler causing himself to go back in time. Check out the example given in the article -- it doesn't involve anyone traveling through time at all

 

[Hagi]

Spoiler: How to kill Hitler without paradoxes:

I believe that is the Predestination Paradox

I was under the impression that the predestination paradox is a time traveller causing himself to go back in time.

As in a person as an infant getting saved by a mysterious man, causing him to live to an old age where time travel is invented. In order to find out who saved him he travels back in time, only to find an infant on the verge of death and him the only person who can save said infant.

Killing Hitler seconds before he commits suicide hardly constitutes causing your own journey, you'd have to cause Hitler to happen for that paradox to go.

The example you gave is an example of the predestination paradox, but the predestination paradox doesn't have to involve a time traveler causing himself to go back in time. Check out the example given in the article -- it doesn't involve anyone traveling through time at all

You don't have to travel through time to cause time travel.

Your given example involves the coworker sending information back in time that causes an event that causes her to send information back in time. Thus she herself is causing her own action of time travel.

Killing Hitler, after he's already committed the atrocities doesn't match this pattern. Him committing said atrocities, the cause of the time travel, isn't impacted by the time travel. Regardless of whether or not the time travel actually occurred the cause for it remains.

The predestination paradox involves a cause for time travel that wouldn't have occurred without that time travel. In effect meaning the instance of time travelling is causing itself, thus it's called predestination.

Going back in time and killing Hitler in 1945 because of atrocities committed before that is not a paradox, predestination or otherwise. The cause for going back in time remains fully intact and unaltered even after the time travel.

 

[Gerishnakov]

Of course the other possibility is that the universe is predestined, everything that will happen has in effect already happened, and you can change nothing because your 'change' is what already happened. IE we know that noone ever goes back in time to kill Hitler, because he didn't get killed.