Does time travel really HAVE to create paradoxes?

[⇛Marnetmar⇛]

I was just thinking about this.

 

If you go back in time to kill baby Hitler, you've created a paradox where you actually couldn't have killed baby Hitler, because if Hitler is what led you to travel back in time in the first place, then you couldn't have gone back in time to kill baby Hitler.

 

But does the universe actually care how you got there in the first place? As far as the universe at the point you time travel to is concerned, you could very well have just magically popped into existence (this violates the law of conservation of mass and I'll get to that in a moment) and still continue existing after killing baby Hitler. 

 

On the flipside, I guess that magically popping into existence is a problem in itself because you've basically added another copy of the atoms that would eventually go on to make up you to the universe. Or maybe not? Maybe this is actually how a theoretical white hole would work? I mean, it doesn't really matter that you've removed those atoms from one version of the universe and added a second copy of them to the other version of the universe because you've gone on to ensure that the version of the universe you came from will never exist in the first place (and like I was saying, does it actually matter how the atoms got there once they're already there? [I mean, it does but y'know])

 

Maybe this is actually a way of demonstrating that time as we know it doesn't actually exist at all and it's therefore pointless to even talk about time travel paradoxes in the first place? It could be that rather than there being multiple universes with multiple timelines like some people propose, there's one universe and "time" doesn't actually exist and therefore time travel doesn't make sense at all because by "time traveling" you'd be violating the law of conservation of mass by taking the atoms that make up you and duplicating them.

 

I have no idea why this brain vomit is pouring out of me but there's no sense in letting perfectly good brain vomit go to waste so I'll dump it on you guys.

Edited January 12, 2021 by Marn

[Jayextee]

I reckon if time travel to the past were possible, any change would simply create a new universe to accomodate the timeline divergence; the future from which the traveler came still exists and continues unabated as if they'd failed in their task, but also the timeline in which the traveler succeeded also exists.

This could mean, again if time travel to the past were possible, infinite combinations of timelines and events and such, but I reckon it's doable. Most people who argue against that kind of thing seem to have some difficulty in perceiving infinites of anything; which is pretty common, actually.

[⇛Marnetmar⇛]

18 minutes ago, Jayextee said:

I reckon if time travel to the past were possible, any change would simply create a new universe to accomodate the timeline divergence; the future from which the traveler came still exists and continues unabated as if they'd failed in their task, but also the timeline in which the traveler succeeded also exists.

This could mean, again if time travel to the past were possible, infinite combinations of timelines and events and such, but I reckon it's doable. Most people who argue against that kind of thing seem to have some difficulty in perceiving infinites of anything; which is pretty common, actually.

 

The thing that I'm not able to wrap my head around with an infinite universe/infinite timeline theory is, provided that it was true, would all these separate universes exist in a tangible way? i.e would all of the atoms and such that make up these universes definitely exist in their own right even if it was impossible to reach one universe from another?

 

If that's the case, how could the actions that anybody takes (or doesn't take) create an entire universe's worth of matter? 

 

Unless maybe you have a single universe with multiple "timelines" which are experienced as time to whoever is living in them but actually just represent some fucky superposition thing of every possible particle configuration for a given universe? So basically you have a set amount of particles, but from the particles' perspective they're actually everywhere at once? Maybe this is basically quantum physics in a nutshell?

 

inb4 someone who's more informed than I am rightly tells me I have no idea what I'm talking about 

Edited January 12, 2021 by Marn

[dmslr]

2 hours ago, Marn said:

this violates the law of conservation of mass

We would have already omitted so many laws only by traveling to the past. I don't see any reason to take the law into account. Personally, I don't believe in time travel to the past or the theory of infinite universes, therefore it all exists just in thought experiments where we can decide would laws allow us to do something, how it could happen and what it would cause. Often in movies we just assume that the universe just allowed us to travel to the past. At this point we should just be interested in paradoxes it have created.

I love to reflect on time travel paradoxes and would be happy to discuss them if my poor English allowed me to do so.

[seed]

3 hours ago, Marn said:

If you go back in time to kill baby Hitler, you've created a paradox where you actually couldn't have killed baby Hitler, because if Hitler is what led you to travel back in time in the first place, then you couldn't have gone back in time to kill baby Hitler.

 

I've not studied enough on this topic but, Jayextee's line of thought makes more sense to me, if you were to do that, it would just create a different timeline, where Hitler was assassinated, while the one where he lives carries on, doing its own thing.

 

What I am more curious about is interacting with yourself, and what consequences such an action would have.

[Dexiaz]

Answer the next question:

 

Stephen Hawking hosted a party for time travelers, but no one came. Is this true, or does Stephen Hawking kept time travelers coming as secret because it will create the time paradox otherwise?

 

But yeah, such dilemma was also seen in Mirai Nikki manga/anime and Quantum Break videogame.

[Yandere_Doomer]

just one of many time travel arguments that i cant wrap my head around...

Why does time travel have to be so complicated?

If i were to go back in time to kill baby Hitler, of course that would create an alternate universe, so maybe there are two versions of me, one in the Hitlerless universe and one in the Hitler...ful universe [where the holocaust happened and whatnot]

when i go to kill baby Hitler and create the new universe, im stuck in that universe, so i can only traverse that universe's timeline unless i were to find a way to prevent myself from killing baby Hitler. but then that would create 3 of me? hmm.... I would only revert back to my own timeline [the Hiterful one] if i kill my other self [so that i wouldnt have a paradox in one universe] so i could revert back to the original timeline.

once i revert to the original timeline, do i merge with my own self? or would i have to kill another me? 

but then i would have to be very careful when killing other versions of me so other people wouldnt see, thus creating another universe where my parents or other people know that i kill my other self.

but what about myself in general? do i have the same thought process throughout all of my selves? or do my other selves do different things based on how the world has changed around them because of my time traveling? so would that create another universe?

Agh! you know what? lets just dont screw with time....

 

[QuotePilgrim]

3 hours ago, Marn said:

The thing that I'm not able to wrap my head around with an infinite universe/infinite timeline theory is, provided that it was true, would all these separate universes exist in a tangible way? i.e would all of the atoms and such that make up these universes definitely exist in their own right even if it was impossible to reach one universe from another? 

Yes.

Thing is the way I see it, time travel is almost definitely impossible, so it doesn't matter what explanation you come up with, they are all equally valid (or rather invalid).

[SiMpLeToNiUm]

I think the way we'd even have to have time travel happen would involve repositioning all of the atoms currently in existence somehow.

There's a tendency to think of time as some outer force that "contains" all the "stuff" of the universe in some sort of convenient package, and the multiverse theories work really well and neatly because there's supposed to be all sorts of these parcels of stuff flying around in some even larger container, but that honestly seems a bit silly. We know there's stuff flying around, so why does there have to be a force of time governing it? What do we really know beyond that (and I could be speaking from total ignorance) to tell us that such a force exists and can even be manipulated? So really, it's not a manipulation of an abstract concept like time so much as it is a manipulation of matter and energy.

 We even see that in certain experiments, no two observers in certain locations have the same perception of events as they unfold, which is more a function of properties of forces than it is actually time. Think of it this way also: where do you get the absolutely mind-boggling amount of energy you'd need to move all atoms back to the positions they were in "in the past?" And, in my opinion, "time travel" is exactly that, a movement of atoms back to a previous position, since if you think about it that way, there's no governing force of "time" keeping atoms in check. It's about energy and movement, not time. So, the absolute specificity and knowledge of the precise position of so many atoms, not only in our small corner of the universe, but every other place all at once seems highly unlikely, to put it simply. Ignoring even that aspect, you'd also have to re-excite or take the exact specific energies from each of those atomic and subatomic molecules all at once as well in their complete arrangement at that point in "time." Where do you get knowledge like that, especially reasonably so, thousands or millions of years into the future when such a technology would even really be feasible given our current tech? Impossible, if you ask me. Also, does moving an atom and changing its energy level really make you go back "in time"? I dunno. Surely you'd need to affect the overall energy of the universe in a non-trivial way to even achieve this "great movement" of stuff, which really would probably affect the way things work in some unplanned-for way, and not even revert time at all like you expected.

[P41R47]

This is the whole concept of the Chrono games.

 

But let make some approaches to the matter of fact:

 

1-When you travel back or forward, you never get at an especified time, like 12 am of 2022, for example. Nope, if you move in this moment, 18:53 hs to the past years, it will be january 2020 tuesday at 18:53 hs.
Time is not an estatic thing, as a dimension, it moves along with space, too.

 

2-You can change event on past that affect future, but that only creates an alternate timeline you awill be experimenting, the other one is still there. Much like Dragon Ball Future Trunk not being the same as Present Trunk, even when he changed the past events. It modified his future, but the whole point of ruined landscape was still achieved by other means.

 

3-This creates different presents, too. One where you are alive, and one where you culd have drown when kid. There is no paradox if you travel from one to another, past at one point, is the same for both reallities, so people that knew you will still knew your past self.

 

4-The paradox approach of time travel is kinda a reductionism on the matter.
Take a shoelace and make a bond with both tips, the bond is where you are, and the tips sprouting are the new timlines created by your meddling.

 

5-Changing one single event alone wouldn't break an entire universe. Thats common sense than anything

 

6-Back To The Future approach to time travel is not accurrated with the actual metaphysic concept. This can be seen when Biff goes back in time and return to the same timeline, even when he already destroyed that timeline, as the Doc tells on a following scene, there is no way he could have returned to the same timeline, nor even usign the time machine, as the Doc was declared insane even before completing it. Not only plot hole, it destroy the intended idea for the film use.

 

7-The whole concept of same matter occupying the same place is feel onto itself, too. If someone from the future contact his own past self, it wouldn't be destroyed.

why? Because over time are soo many chemical changes on our body that, it hardly is the same body years after. So its not the the same matter anymore.

 

This are some insights i had through (oh the irony) time.

[TenenteZashu]

It's convenient to the plot

[HQDefault]

Yeah I always figured if time travel was a thing, you'd just create a new timeline and then get sent back to said new timeline. I guess the important part is whether or not the law of conservation of mass absolutely demands that all matter remains in the same universe, but if not and it's still considered valid if the matter just goes to a different reality, then yeah it's probably the alternate timeline thing.

 

Also you know the running joke that's like "if time travel is possible, where are all the tourists from the future?" Imagine how absolutely nuts it would be if you were in the timeline that had all the time travelling tourists that didn't give a damn about secrecy. You knew it would be invented one day and sometimes you just randomly find a guy in some cyber-punk esc jumpsuit taking photos with his bionic eyes and you're just like "oh great, time foreigners."

[Sergeant_Mark_IV]

The only way this can work is with multiple timelines. The traveler abandons it's timeline to enter another one. The abandoned timeline continues to exist and progress normally.
A paradox can only be prevented if the actions he made can not prevent the unfolding of events that happened on his original timeline, which will lead into another travel and ruining another timeline, infinitely.
And if he lives enough to the date of his birth, he may be able to meet "himself", because they are actually two different people. 

[Yandere_Doomer]

18 minutes ago, Sergeant_Mark_IV said:

The only way this can work is with multiple timelines. The traveler abandons it's timeline to enter another one. The abandoned timeline continues to exist and progress normally.
A paradox can only be prevented if the actions he made can not prevent the unfolding of events that happened on his original timeline, which will lead into another travel and ruining another timeline, infinitely.
And if he lives enough to the date of his birth, he may be able to meet "himself", because they are actually two different people. 

i was also thinking, if you and yourself were in another timeline, would it be necessary to kill yourself [or your other self] to prevent a paradox that causes a catastrophe to the space-time continuum? what if you trip while stabbing baby Hitler and your knife kills the Hitler family frog[why a frog? dont ask] causing the butterfly effect that leads to the overpopulation of flies? or what if you killing baby Hitler leads to a much more powerful leader creating a much worse regime that actually WINS the war?

causing a dystopian future where everybody lives in fear?

the whole time travel theory and all of these "effects" have so many twists and turns it would be near impossible for us average people to understand.

but it is a fun topic to bring up....

 

 

[Roebloz]

I think I got the perfect answer to this:

 

You cannot grasp the TRUE form of Giygas Time Travel's attack!

 

No really, it's not possible to understand time travel until its invented. If it is invented. For now, let's use it as a cheap plot-convenient tool.

[insertwackynamehere]

3 hours ago, SiMpLeToNiUm said:

snip

I think this sort of is related to https://en.wikipedia.org/wiki/Arrow_of_time

[wolfmcbeard]

Time travel exists for the sole purpose of the entirety of Star Trek: Enterprise season 3.

I don't think we'd ever fully understand time travel, and maybe that's simply because it's such a wild idea that it's not conceivable in this day and age, outside of science fiction.

 

[pilottobombadier]

I think that we are underthinking some of those paradoxes. 

Killing Hitler at infancy is a perfect example. 

Killing Hitler would not have stopped the Nazi movement, they'd have gotten someone else.  Stopping the Nazi movement in the 1930's would've required preventing WWI, or at the least, preventing Germany from getting a total screw job.  Even then, it wouldn't have stopped it from growing, and worse, it would have been able to grow unabated.  Imagine if that movement came to power after the dawn of atomic weapons.

At the same time, WWII created the perceived need for atomic weapons (and thus all of the advents of the so-called Nuclear Age), and that need would be affected by the lack of a second world war.

So, killing baby Hitler wouldn't stop that, not by a long shot.  What it would do, is create a different world, vastly different from the one that you're in.  Or possibly hardly changed at all.  Or possibly not changed at all.

Ultimately, you'd have to alter major events very far back to stop major cultural shifts that were an inevitability because of that distant past.  

[kalaeth]

(just a side note for the "killing Hitler", there's a really good book by Stephen Fry (yes, that one) about it : https://en.wikipedia.org/wiki/Making_History_(novel) )

 

 

About the paradoxes.. Well, first we don't even know if time actually exists as something, and if it does if it is a straight line or, using Doctor Who terminology a "big ball of wibbly wobbly... time-y wimey... stuff". If it is a straight line, and disregarding the whole problem of making a new version of someone (maybe we can only send a "soul" back into the past (check TV show Travelers, it gets wore but it has an interesting time travel premisse)), then the future where you came from stop existing and a new one forms. Like.. You cut the thread and the new future begins the moment you step into the past (or it branches into a new future and then time traveling will never make the future better or worse), and at the moment you (say) kill Hitler there isn't a future yet, so no paradox. 

 Or time is constant  (some parts of I think buddhism believe something like this, the past, present and future are whole) and then if you change something in the past whatever is in the present/future immediately changes into what it will be and since you were a secret grand-grand-grand nephew of Hitler's bastard son you don't exist anymore and then can't travel back and so a paradox is created and time collapses on itself and the universe is destroyed. Or you just disappear but Hitler stays dead. 

 

Oh, one more thing : why would you kill _baby_ Hitler when you can just travel back to WW I and kill him there? Do you have some weird baby killing fetish or what?

[dmslr]

2 hours ago, kalaeth said:

why would you kill _baby_ Hitler when you can just travel back to WW I and kill him there? Do you have some weird baby killing fetish or what?

Maybe they just want to be sure he won't sow ideas in someone's mind. But still, killing a baby is fucking evil.

[pilottobombadier]

11 hours ago, dmslr said:

Maybe they just want to be sure he won't sow ideas in someone's mind. But still, killing a baby is fucking evil.

Besides, why kill him as an infant when you can abduct him and put him in a better, loving home?

[Yandere_Doomer]

23 minutes ago, pilottobombadier said:

Besides, why kill him as an infant when you can abduct him and put him in a better, loving home?

no, i am not wasting all of that time [pun intended] for Hitler to possibly not grow up to be a psychopath. he will end just as soon as he starts.

 

 

[DooM Bear]

Short answer is no, you don’t always cause paradoxes with time travel.

 

Time travel to the future would not cause any issues at all :-)

 

Time travel to the past however, yes, under our current understanding of physics you are theoretically always going to create a paradox. There are thousands of reasons why this might be the case but take the butterfly effect or the observer effect for example, going off these theories possibly just the act of being there and seeing things could change things dramatically down the road.

 

That said, all these things (including the paradoxes) are theories so who knows! We might be completely wrong about it all and could be surrounded by time travellers from the future right now :-D

[pilottobombadier]

4 minutes ago, Deathclaw886 said:

no, i am not wasting all of that time [pun intended] for Hitler to possibly not grow up to be a psychopath. he will end just as soon as he starts.

 

 

Pot calling the kettle black? ;) 

Also, I wouldn't waste the time to kill Hitler at all.  It wouldn't do shit, the Nazis will most likely still rise.  Plus, it may put Stalin in a much better position militarily, and instead you have a second world war with Soviet Russia at a later point in our timeline.  

Never mind the paradoxes, people never really discuss the consequences.

[seed]

7 hours ago, pilottobombadier said:

Also, I wouldn't waste the time to kill Hitler at all.  It wouldn't do shit, the Nazis will most likely still rise.  Plus, it may put Stalin in a much better position militarily, and instead you have a second world war with Soviet Russia at a later point in our timeline.  

Never mind the paradoxes, people never really discuss the consequences.

 

Indeed, who knows if, by eliminating a great problem, you don't give birth to a bigger one. And what of his enemies? This would give them a pretty big advantage over the Nazi.

 

If anything, Hitler was a symptom of a larger problem of the time, not the root cause.

[Gez]

1 hour ago, seed said:

If anything, Hitler was a symptom of a larger problem of the time, not the root cause.

Yes, this is what's forgotten by all the "Kill Baby Hitler" scenarios out there (and their variants). The roots of Nazi ideology are older than him, and notably the concept of Lebensraum dates from late 19th century and is what motivated the Septemberprogramm of WW1 (which was aborted due to German armies getting stalemated in trench warfare) as well as the Herero and Namaqua genocide in Namibia. Seize territories held by "inferior" people, slaughter them all, and resettle with Germans.

 

If you go back in time and kill Hitler, the likely consequence is another Führer taking his place in history and doing pretty much the same things. After all, it's not like he was the only prominent potential Nazi leader; in fact the Night of Long Knives was made to get rid of the competition. Remove Adolf Hitler and maybe the next time traveler have to assassinate Ernst Röhm or Gregor Strasser as well.