JJ-Trek/ IDW Continuity and Discontinuities

[Mr. Laser Beam]

^ Fair enough.

As I said in another thread, as long as the Prime timeline remains and is not wiped out (Pegg's initial comments did give me some pause on that point), then the Kelvinverse can do whatever the hell it likes.

 

[Christopher]

"Oi" is right. IMHO, if they had wanted to be a hard reboot, they should've just done that from square one.

Different "they." Abrams, Lindelof, Orci, and Kurtzman made a choice to do it a certain way. Now Lin, Pegg, and Jung (with Abrams overseeing them from a greater distance) have decided to do things differently. I've already addressed this. It shouldn't be so difficult to understand that new creators might decide to do things differently than the previous team did.

Is it a bad thing if I'm asking how this time travel model supposed to work in the context of the larger franchise, and question whether it does or not based on what we've seen before?

No, except I already answered your questions days ago, and you keep ignoring my answers and restating the same questions. Why even ask the questions if you won't listen to the answers?

Same scene, but in one, Sisko and Dax were not there. But, the first version (without them) also happened. I'm having trouble understanding how this incident would fit your model, since there's a timeline (or version of one) in which Sisko and Dax were not there, and then there was one where they were there. Two different versions of the same event with visible differences. That would seem to prove that were was a "before" and "after," since they're mutually exclusive, despite both happening. I'm having trouble understanding how it's an illusion that there are two consecutive versions here.

Does this make any sense? What am I missing about this in regards to your theory?

Look. They're the same moment in time. Therefore, they happen at the same time. That much should be incredibly obvious. As far as the universe is concerned, they are both happening simultaneously, at the exact same moment, because they are the exact same moment. They're running side-by-side in parallel timelines. But if a time traveler experiences one version of that moment, then goes back in time and experiences the parallel version of the same moment, it looks to that individual traveler as if they are consecutive. Because the traveler is looping back and experiencing the same moment twice. But objectively, by definition, they're the same moment so they happen at the same time.

Saying that a single moment in time can come after itself is a contradiction in terms. It's like saying the North Pole is north of the North Pole. It's like saying 5 is bigger than 5. It doesn't make any damn sense. If you live through one version of July 26, 2016, then go back in time and change it to a different version of July 26, 2016, they're still both the exact same day. They are, by definition, simultaneous. It's only from your own subjective point of view that one came before the other, but that's an illusion resulting from your abnormal movement through time.

Memory Beta now used the term "Kelvin-timeline" in their USS Franklin article.

Only in a sidebar link that gets redirected to the "Alternate reality" page. I doubt it'll last long.

 

[WebLurker]

Different "they." Abrams, Lindelof, Orci, and Kurtzman made a choice to do it a certain way. Now Lin, Pegg, and Jung (with Abrams overseeing them from a greater distance) have decided to do things differently. I've already addressed this. It shouldn't be so difficult to understand that new creators might decide to do things differently than the previous team did.

Believe it or not, I do understand that. I'm only asking if the change fits the evidence (which there is some disagreement on).

No, except I already answered your questions days ago, and you keep ignoring my answers and restating the same questions. Why even ask the questions if you won't listen to the answers?

Sorry. But, you know what? I feel like I'm in the same position, too.

Look. They're the same moment in time. Therefore, they happen at the same time. That much should be incredibly obvious. As far as the universe is concerned, they are both happening simultaneously, at the exact same moment, because they are the exact same moment. They're running side-by-side in parallel timelines. But if a time traveler experiences one version of that moment, then goes back in time and experiences the parallel version of the same moment, it looks to that individual traveler as if they are consecutive. Because the traveler is looping back and experiencing the same moment twice. But objectively, by definition, they're the same moment so they happen at the same time.

Saying that a single moment in time can come after itself is a contradiction in terms. It's like saying the North Pole is north of the North Pole. It's like saying 5 is bigger than 5. It doesn't make any damn sense. If you live through one version of July 26, 2016, then go back in time and change it to a different version of July 26, 2016, they're still both the exact same day. They are, by definition, simultaneous. It's only from your own subjective point of view that one came before the other, but that's an illusion resulting from your abnormal movement through time.

So, would I be correct in assuming you're basically advocating for the "many worlds" theory, kind of like was originally suggested for the '09 movie? How would that work with stories written with the assumption that one single timeline is being altered, but no parallel realities are being made?

 

[Christopher]

So, would I be correct in assuming you're basically advocating for the "many worlds" theory, kind of like was originally suggested for the '09 movie? How would that work with stories written with the assumption that one single timeline is being altered, but no parallel realities are being made?

Doesn't matter. The same time is the same time. It's a contradiction in terms to say the same time comes after itself. They have to be parallel, and stories that assume one is "replacing" the other are just plain getting it wrong. The only way I could rationalize that in my DTI novels is by positing that they were parallel up until the moment of the original time travel, whereupon they merged together and the original history was forgotten from then on, so it was as if it had been erased.

 

[JD]

Same scene, but in one, Sisko and Dax were not there. But, the first version (without them) also happened. I'm having trouble understanding how this incident would fit your model, since there's a timeline (or version of one) in which Sisko and Dax were not there, and then there was one where they were there. Two different versions of the same event with visible differences. That would seem to prove that were was a "before" and "after," since they're mutually exclusive, despite both happening. I'm having trouble understanding how it's an illusion that there are two consecutive versions here.

Personally, I had always assumed that in universe they would be there in both pictures, and the only reason we didn't see them in TOS one was for the real world reason of Trials and Tribble-ations not being around for another 29 years.

 

[Christopher]

Personally, I had always assumed that in universe they would be there in both pictures, and the only reason we didn't see them in TOS one was for the real world reason of Trials and Tribble-ations not being around for another 29 years.

The evidence for that being that the tribbles that hit Kirk on the head were the same ones Sisko tossed out of the cargo bay. How could those same tribbles have hit him in the original footage if Sisko wasn't there to begin with???

Although I tend to assume there was a minor divergence/parallelism in the timeline caused by the DS9 characters' arrival, but that its effects were minimal enough that the timelines then reconverged.

 

[Idran]

So, would I be correct in assuming you're basically advocating for the "many worlds" theory, kind of like was originally suggested for the '09 movie? How would that work with stories written with the assumption that one single timeline is being altered, but no parallel realities are being made?

I think this might help put thoughts in order, WebLurker. Can you spell out in as much detail as you can what exactly you mean when you use the phrase "X happened before Y"? Not with any specificity, without calling to examples, just as general a situation as that. Trying to elaborate on what exactly that means might help to highlight things for you. A lot of times these issues come down to unrealized assumptions buried in vocabulary.

 

[WebLurker]

The evidence for that being that the tribbles that hit Kirk on the head were the same ones Sisko tossed out of the cargo bay. How could those same tribbles have hit him in the original footage if Sisko wasn't there to begin with???

Well, since the original episode shows tribbles still falling on Kirk even after Sisko and Dax have found the bomb, and have no reason to be tossing them (around the time that Kirk asks for the storage door to be shut), I could believe if there was an original iteration of the timeline where the DS9 crew wasn't there, that Kirk would still get hit with tribbles.

Although I tend to assume there was a minor divergence/parallelism in the timeline caused by the DS9 characters' arrival, but that its effects were minimal enough that the timelines then reconverged.

Okay, I see.

I think this might help put thoughts in order, WebLurker. Can you spell out in as much detail as you can what exactly you mean when you use the phrase "X happened before Y"? Not with any specificity, without calling to examples, just as general a situation as that. Trying to elaborate on what exactly that means might help to highlight things for you. A lot of times these issues come down to unrealized assumptions buried in vocabulary.

I think that the line between the "before" and "after" point in time travel is the actual moment that the time travelers arrive at their destination. The history books written before the time traveler went back would say things happened the original way, but when they got back to their home time, the same book would be modified. So, there's the before and after; the original iteration, the messed up one, and the repaired one (if the time traveler wants to fix things).

It's admittedly only a before and after from an outside viewpoint, but it's not that much different from editing a text document. The altered text may not change the page it's printed on (like Mr. Bennett's statement that they have to happen at the same time), but there is a before when it was different.

Does that make any sense?

 

[Christopher]

I think that the line between the "before" and "after" point in time travel is the actual moment that the time travelers arrive at their destination. The history books written before the time traveler went back would say things happened the original way, but when they got back to their home time, the same book would be modified.

But "before" from whose perspective? That's the assumption you're failing to question. If the time traveler is going backward in time, then obviously their perception of "before" is different from that of the rest of the universe. So why should their unnatural perception of the order of things override how everyone else perceives it?

An analogy: We TV viewers saw the events of the 23rd century in TOS and the 24th century in TNG, DS9, and VGR before we saw the events of the 22nd century in ENT. We went "back in time" because the show about the earlier century was made later. But as far as the inhabitants of the Trek universe are concerned, Archer came before Kirk. That's two mutually incompatible definitions of the word "before." It's the same if you're a time traveler in-universe. Look at "Time's Arrow," and how Picard and Guinan had contradictory perceptions of when they first met. From Guinan's perspective, she met Picard in 1893 before she met him in the 24th century. But from Picard's perspective, he met her in the 24th century before he encountered her in 1893. You cannot treat "before" and "after" as words that have an absolute, singular meaning when you're talking about time travel. They're relative terms, perceived differently by different observers.

So when you say "before the time traveler went back," what does that mean? From the time traveler's personal perspective, or from our perspective as viewers of the story, it looks like the traveler was in the future before he went back to the past. But as far as everybody else in the universe is concerned, the time traveler was in the past before he was born in the future. From Guinan's perspective, the adult Picard's arrival in 1893 came before his birth in 2305, because that's what "before" means for everyone who isn't traveling in time. As far as an objective observer is concerned, the time traveler's arrival in the past happened before everything else in the time traveler's life. That's why Guinan already remembered meeting Picard in 1893 even before he went back in time.

It's admittedly only a before and after from an outside viewpoint, but it's not that much different from editing a text document. The altered text may not change the page it's printed on (like Mr. Bennett's statement that they have to happen at the same time), but there is a before when it was different.

Does that make any sense?

No. It makes no sense at all, because you're mistaking the time traveler's subjective, distorted perception of the sequence of events for an absolute truth. It's only from the time traveler's POV that one version of history comes "before" the other. As far as an objective observer would be concerned, the two timelines happen at the same time.

 

[Hartzilla2007]

Meh, I'm still sticking with DC Comics time boom theory.

 

[Idran]

I think that the line between the "before" and "after" point in time travel is the actual moment that the time travelers arrive at their destination. The history books written before the time traveler went back would say things happened the original way, but when they got back to their home time, the same book would be modified. So, there's the before and after; the original iteration, the messed up one, and the repaired one (if the time traveler wants to fix things).

It's admittedly only a before and after from an outside viewpoint, but it's not that much different from editing a text document. The altered text may not change the page it's printed on (like Mr. Bennett's statement that they have to happen at the same time), but there is a before when it was different.

That's not actually what I'm asking. You're talking specifically about this example still, but I'm asking about the word itself as you intend it.

What I mean is can you spell out precisely what you mean when you use the word "before"? Your exact definition of that word, as precisely as you can. Not, like, a dictionary reference, since no one's internal thought processes include a dictionary, but your internal definition in your own mental concept web.

Like, can you explain what specifically "X happened before Y" means as you use it, without assuming any details at all about what "X" or "Y" refer to? If we're using the word "before" in a different way than you're using the word "before", after all, then we won't get anywhere. It's important to get on the same vocabulary footing when it's such a fundamental point like this.

For example, when I say "X happened before Y", what I mean is "the moment in time associated with the event X according to my own current perspective is earlier in absolute chronological progression than the moment in time associated with the event Y according to my own current perspective". Can you do something similar to what I did just there?

 

[ryan123450]

I hate to poke my head into this fray because its alot deeper and semantic than I want to delve into for a lengthy discussion...
But I will say that I think causality may have an important place here even more than temporality. For example the events as they progressed in T&T were caused by an event which happened one hundred years after the events that progressed in TTWT. That information as some bearing on the "before" and "after" of it all.

Not sure what exact use that point has to either side of this discussion, but it seemed like an important framework of the events to point out.

 

[Idran]

That is a good point; I don't think that basing your usage of "before" and "after" on causality rather than chronology is necessarily invalid, since the two are coincident and interchangeable under all normal situations. So it's certainly defensible as a definition. If that's what WebLurker means, then that makes the reason for the division much more clear; both sides seem to be correct with regard to their intended meaning in that case, and it's just confusion arising by using the same word to refer to two different concepts.

The only issue I'd see is that the terms would break down when you get a chain of events that form a causal loop, but that's not really a huge issue.

Edit: You know, the more I think about that, the more interesting it is to me. Like I said, the two are interchangeable in normal usage, so you would assume that they would be in internal thought processes too; you wouldn't think that you'd run into enough situations where the two were distinguished concepts that they'd link up mentally in very distinct ways, that they'd almost entirely overlap in a person's mind too. And yet, for myself at least, the chronology aspect is innately more primary than the causality aspect in my mind, strongly enough that it at least feels like it's always been part of how I've understood the word.

This is 100% a tangent from everything in this thread, but sometimes I'm just struck at the amazingly intriguing nature of the way the brain assigns meaning to words.

 

[Dayton Ward]

FYI, I've deployed Spock and some red matter to a point in the thread before all this started.

 

[Christopher]

FYI, I've deployed Spock and some red matter to a point in the thread before all this started.

Which I'm sure will come as a comfort to the alternate versions of ourselves in the timeline that branches off as a result. Or, rather, will have come, since it already happened...

 

[Enterprise1701]

Say, Christopher, with regard to the principle of "everything exists, before and after is subjective from an observer's perspective", does that mean that

Spoiler: The Collectors

in DTI - The Collectors, it is possible that the Aegis of the TIA timeline already foresaw that Noi, Lucsly, and Dulmur would resolve the gung-ho Federation problem for them?

 

[WebLurker]

That's not actually what I'm asking. You're talking specifically about this example still, but I'm asking about the word itself as you intend it.

What I mean is can you spell out precisely what you mean when you use the word "before"? Your exact definition of that word, as precisely as you can. Not, like, a dictionary reference, since no one's internal thought processes include a dictionary, but your internal definition in your own mental concept web.

Like, can you explain what specifically "X happened before Y" means as you use it, without assuming any details at all about what "X" or "Y" refer to? If we're using the word "before" in a different way than you're using the word "before", after all, then we won't get anywhere. It's important to get on the same vocabulary footing when it's such a fundamental point like this.

For example, when I say "X happened before Y", what I mean is "the moment in time associated with the event X according to my own current perspective is earlier in absolute chronological progression than the moment in time associated with the event Y according to my own current perspective". Can you do something similar to what I did just there?

My brain hurts.

"Before" to me would be the unaltered timeline, with "after" being the edited one. Does that answer the question?

But "before" from whose perspective? That's the assumption you're failing to question. If the time traveler is going backward in time, then obviously their perception of "before" is different from that of the rest of the universe. So why should their unnatural perception of the order of things override how everyone else perceives it?

So, even subjectively, there's no way to process that there was an iteration of the timeline that was different?

An analogy: We TV viewers saw the events of the 23rd century in TOS and the 24th century in TNG, DS9, and VGR before we saw the events of the 22nd century in ENT. We went "back in time" because the show about the earlier century was made later. But as far as the inhabitants of the Trek universe are concerned, Archer came before Kirk. That's two mutually incompatible definitions of the word "before." It's the same if you're a time traveler in-universe. Look at "Time's Arrow," and how Picard and Guinan had contradictory perceptions of when they first met. From Guinan's perspective, she met Picard in 1893 before she met him in the 24th century. But from Picard's perspective, he met her in the 24th century before he encountered her in 1893. You cannot treat "before" and "after" as words that have an absolute, singular meaning when you're talking about time travel. They're relative terms, perceived differently by different observers.

Okay, but how then, do we organize cause and effect for time travel?

So when you say "before the time traveler went back," what does that mean?

I mean the iteration of the timeline where the time traveler didn't change the past. The one where the grew up, built their time machine, and then went back and killed Hitler or whatever. So, "before" is the original timeline, and "after" is the altered one. Does that work or am I still missing what you're trying to tell me?

From the time traveler's personal perspective, or from our perspective as viewers of the story, it looks like the traveler was in the future before he went back to the past. But as far as everybody else in the universe is concerned, the time traveler was in the past before he was born in the future. From Guinan's perspective, the adult Picard's arrival in 1893 came before his birth in 2305, because that's what "before" means for everyone who isn't traveling in time. As far as an objective observer is concerned, the time traveler's arrival in the past happened before everything else in the time traveler's life. That's why Guinan already remembered meeting Picard in 1893 even before he went back in time.

Wasn't that a predestination paradox? There would be no alternate timelines, since all the events always happened on one timeline. I'm trying to make sense of how your model works when history is changed, creating different versions of events.

No. It makes no sense at all, because you're mistaking the time traveler's subjective, distorted perception of the sequence of events for an absolute truth. It's only from the time traveler's POV that one version of history comes "before" the other. As far as an objective observer would be concerned, the two timelines happen at the same time.

I guess?

 

[Christopher]

"Before" to me would be the unaltered timeline, with "after" being the edited one. Does that answer the question?

But that's only the way it's perceived by a time traveler who moves from the altered one to the "edited" one. Again, as far as objective observers are concerned, 7:10 PM on July 27, 2016 is a single moment that cannot come after itself. If there are two different versions of 7:10 PM on July 27, 2016, then by definition they coexist simultaneously.

So, even subjectively, there's no way to process that there was an iteration of the timeline that was different?

Of course they're different. There are two distinct versions, the "unaltered" one and the "edited" one. They just exist side-by-side, in parallel timelines, rather than one coming "after" the other. It may seem strange to you that the altered one already exists "before" the time travel that alters it, but that's because you're limited to conventional notions of causality, notions that become irrelevant the moment backward time travel is put on the table. If you can travel backward, then effect can come before cause. That's what time travel is.

Okay, but how then, do we organize cause and effect for time travel?

By replacing "after" with "as a result of." The definitions of "before" and "after" will be different for different observers. They are not absolutes, so they are not useful in this context. But an event can still be a result of a time traveler's action even if it comes before that action.

Try to imagine stepping outside of time and seeing all events and timelines as a single graph. The past is to the left, the future is to the right, and the various alternate timelines branch out above and below each other. Time travelers' journeys are curved lines that cross from one to the other. Since you're looking from outside of time, past and future are simultaneous. Before and after are just directions. Cause and effect are just geometric paths through the map. That's how I visualize it. Going back in time means following a curve that loops back to the left side of the graph and impinges on itself. (Physicists actually call this a "closed timelike curve.") If it creates an alternate timeline, then that timeline splits off at that point on the graph and stretches ahead to the right. It doesn't "appear" there; it's always there, just as every timeline is already there, because you're seeing time from the outside. But observers following paths inside those worldlines, those curves on the graph, can't see the whole picture. They can only perceive what's to the left of them on their worldlines, or to the right of them if the lines curve backward. So if someone's worldline curves backward on itself and then moves forward again in an alternate timeline, it looks to that observer as if the alternate path has only just "appeared." But it was there all along; the time traveler's path just hadn't reached it yet.

Wasn't that a predestination paradox? There would be no alternate timelines, since all the events always happened on one timeline.

I hate the use of the term "paradox" for that in "Trials and Tribble-ations," because it's actually the exact opposite of a paradox. A paradox is a self-contradictory process that doesn't resolve -- for instance, "This statement is a lie." There's no way to resolve it, no outcome possible. A time loop that causes itself is not a paradox, because it does have a single, self-consistent outcome. It seems like a paradox because it contradicts our conventional notions of causality, but again, those notions cease to be correct when time travel is bidirectional. Mathematically, physically, there is nothing wrong with the idea of an event looping back in time and causing itself to happen. What would be a paradox is if it looped back in time and caused itself not to happen. Because then you get an irresolvable loop -- if it didn't happen, then you didn't travel back in time to stop it, so it did happen, so you did go back in time, so it didn't happen, so you didn't go back in time... etc. The way it's usually portrayed in fiction is the paradoxical version.

I'm trying to make sense of how your model works when history is changed, creating different versions of events.

That's where parallel timelines come in. The only resolvable, non-paradoxical way that the event can happen two different ways is if they happened in parallel realities. You did go back in time and prevent yourself from going back in time, but you prevent it in a second timeline that splits off from the first as a result. The first one remains, because it has to remain, because the act of your going back in time still has to be part of the overall process in order for it to make sense.

 

[WebLurker]

But that's only the way it's perceived by a time traveler who moves from the altered one to the "edited" one. Again, as far as objective observers are concerned, 7:10 PM on July 27, 2016 is a single moment that cannot come after itself. If there are two different versions of 7:10 PM on July 27, 2016, then by definition they coexist simultaneously.

My brain still hurts, but I'll give you the benefit of the doubt.

Of course they're different. There are two distinct versions, the "unaltered" one and the "edited" one. They just exist side-by-side, in parallel timelines, rather than one coming "after" the other. It may seem strange to you that the altered one already exists "before" the time travel that alters it, but that's because you're limited to conventional notions of causality, notions that become irrelevant the moment backward time travel is put on the table. If you can travel backward, then effect can come before cause. That's what time travel is.

Can I ask a question? How is it "proven" that the time travel creates two coexisting parallel timelines, instead of the most recent version overwriting the other, since that would seem to solve the problem? At the end of the day, there's only one date X, it just replaced a version that no longer exists. (Sorry if I'm not getting it, but just saying "if it already happened, it can't unhappen" seems to be ignoring part of the idea behind time travel, IMHO. It's also an interesting enough discussion that more explanation would be appreciated.)

By replacing "after" with "as a result of." The definitions of "before" and "after" will be different for different observers. They are not absolutes, so they are not useful in this context. But an event can still be a result of a time traveler's action even if it comes before that action.

Okay.

But that's only the way it's perceived by a time traveler who moves from the altered one to the "edited" one. Again, as far as objective observers are concerned, 7:10 PM on July 27, 2016 is a single moment that cannot come after itself. If there are two different versions of 7:10 PM on July 27, 2016, then by definition they coexist simultaneously.

My brain still hurts, but I'll give you the benefit of the doubt (save for the previous question about if there are any alternatives).

Try to imagine stepping outside of time and seeing all events and timelines as a single graph. The past is to the left, the future is to the right, and the various alternate timelines branch out above and below each other. Time travelers' journeys are curved lines that cross from one to the other. Since you're looking from outside of time, past and future are simultaneous. Before and after are just directions. Cause and effect are just geometric paths through the map. That's how I visualize it. Going back in time means following a curve that loops back to the left side of the graph and impinges on itself. (Physicists actually call this a "closed timelike curve.") If it creates an alternate timeline, then that timeline splits off at that point on the graph and stretches ahead to the right. It doesn't "appear" there; it's always there, just as every timeline is already there, because you're seeing time from the outside. But observers following paths inside those worldlines, those curves on the graph, can't see the whole picture. They can only perceive what's to the left of them on their worldlines, or to the right of them if the lines curve backward. So if someone's worldline curves backward on itself and then moves forward again in an alternate timeline, it looks to that observer as if the alternate path has only just "appeared." But it was there all along; the time traveler's path just hadn't reached it yet.

I think I get the part about a person's personal timeline looping back, thanks to time travel. So, you're saying that all time travel events have "already" happened, even "before" the time traveler chooses to go back? Wouldn't that affect free will, though?

Also, would this model still apply/look like this if the time travel wasn't "supposed" to happen? For example, in "Carpenter Street" (ENT), Daniels tells Archer that the Xindi attack on Earth wasn't part of the "original" timeline, his future faction has no records of it and the NX-01's mission to stop it happening, and the faction has no idea what the outcome is going to be like. How would such a scenario fit your model?

I hate the use of the term "paradox" for that in "Trials and Tribble-ations," because it's actually the exact opposite of a paradox.

I was actually referring to the Picard and Guinen example from "Time's Arrow." Does your thoughts on "paradox" being the wrong term apply to that, too?

A paradox is a self-contradictory process that doesn't resolve -- for instance, "This statement is a lie." There's no way to resolve it, no outcome possible. A time loop that causes itself is not a paradox, because it does have a single, self-consistent outcome. It seems like a paradox because it contradicts our conventional notions of causality, but again, those notions cease to be correct when time travel is bidirectional. Mathematically, physically, there is nothing wrong with the idea of an event looping back in time and causing itself to happen.

I thought predestination paradoxes were called "paradoxes" because of the way that the effect triggers the cause, basically reversing cause and effect. I will agree, though, that I think these "paradoxes" are the more logical ones and make sense, at least on paper. I never had a problem with them, personally,

What would be a paradox is if it looped back in time and caused itself not to happen. Because then you get an irresolvable loop -- if it didn't happen, then you didn't travel back in time to stop it, so it did happen, so you did go back in time, so it didn't happen, so you didn't go back in time... etc. The way it's usually portrayed in fiction is the paradoxical version.

Would Trek shows like "Timeless" (VOY) and "Twilight" (ENT) be examples of this paradox?

That's where parallel timelines come in. The only resolvable, non-paradoxical way that the event can happen two different ways is if they happened in parallel realities. You did go back in time and prevent yourself from going back in time, but you prevent it in a second timeline that splits off from the first as a result. The first one remains, because it has to remain, because the act of your going back in time still has to be part of the overall process in order for it to make sense.

Hypothetical: say that the "many worlds" theory wasn't usable. What do you think would be the best alternative explanation?

I do have a couple of questions:

Wouldn't the many worlds theory also make predestination paradoxes impossible? That scenario depends on the time travelers staying in their own timeline, not going off into a new one.

In a lot of Trek time travel shows, the timeline is shown changing around the characters (like in "Yesterday's Enterprise" [TNG]). Would that still happen in a many worlds time travel model? Because, if the time travel creates an alternate timeline, wouldn't the "original" root timeline be unaffected (except for the missing time travelers), while the new timeline is the one that the time travelers mess up?

In other words, how would a story like "Yesterday's Enterprise" work in the many worlds model? (What parts would be the root timeline, the new timeline, how would the fix of sending the Enterprise-C back be explained? Those are the things I'm trying to make sense of.)

 

[Christopher]

Can I ask a question? How is it "proven" that the time travel creates two coexisting parallel timelines, instead of the most recent version overwriting the other, since that would seem to solve the problem? At the end of the day, there's only one date X, it just replaced a version that no longer exists.

Because that is a self-contradictory statement. It's meaningless. One version of a single moment in time cannot change into a different one, because change requires the passage of time. It requires a "before" version and an "after" version, and as I've been trying to explain to you, a single moment in time cannot come after itself. All the words you're using -- "overwriting," "replaced," "no longer exists" -- assume that time has passed. They're referring to two consecutive versions, to versions that occupy different moments of time. But we are talking about two different versions of the same moment in time. So none of those words that require duration or consecutivity are applicable here.

I don't know why it's so hard for you to understand this. If two things happen at the same moment, they are simultaneous, not consecutive. That is a very simple, basic concept. That is the literal definition of those words.

(Sorry if I'm not getting it, but just saying "if it already happened, it can't unhappen" seems to be ignoring part of the idea behind time travel, IMHO. It's also an interesting enough discussion that more explanation would be appreciated.)

It's ignoring the way time travel is usually portrayed in fiction, but -- news flash -- fiction isn't real. It deliberately portrays time travel in a physically absurd and logically contradictory way because that is more dramatically satisfying. But you should never, ever mistake what you've been told by fiction for a legitimate grounding in how science works. Fiction routinely portrays reality unrealistically. For instance, anyone who's ever witnessed a thunderstorm knows that the sound of the thunder comes after the lightning unless it's right on top of you, but for some bizarre reason, movie sound designers always, always make the thunder simultaneous with the lightning even though virtually everyone in the world has firsthand experience telling them that's wrong. And then there are all the sci-fi movies where you can see the stars outside a spaceship window even when it's brightly lit inside, when everyone who's ever looked out a window at night when the lights are on should know that's wrong. Fiction takes license. It's not a guide for how things really work.

I think I get the part about a person's personal timeline looping back, thanks to time travel. So, you're saying that all time travel events have "already" happened, even "before" the time traveler chooses to go back? Wouldn't that affect free will, though?

No, because these things are relative. How you perceive the universe depends on your point of view. You're still trying to assume there's a single absolute interpretation of things, but Einstein blew that notion out of the water over a century ago.

Free will exists, because the decisions you make haven't been made yet. But you only get to make them once. If you go back in time, it might look like events are happening a second time, but they aren't. You're just seeing their one and only occurrence a second time. It's like replaying a ball game on your DVR. You see the game played again, but nothing you do can change the outcome. Which can make you feel like you have no free will. But that's just because the choices were already made. Free will isn't the illusion; the absence of free will is an illusion created by time travel.

Put another way, our free will is always constrained by our circumstances. We're free to do what our situation allows us to do, and some situations are more constraining than others. The analogy I like to use is that if you're standing on an open plain, you have free will to move anywhere you want in two dimension (though not in the third), but if you then fall off a cliff, your freedom to decide your direction of movement becomes far more restricted. Time travel is like falling off a cliff. It puts far more limits on your freedom to affect outcomes than you would normally have, because it's an atypical situation.

Of course, again, fiction routinely portrays it unrealistically for dramatic effect, since it's less interesting if your characters have no power to affect events (although there have been a number of powerful time-travel stories built around the immutability of history, like the movie 12 Monkeys or Heinlein's "--All You Zombies--"). But you're still seeing those events from the perspective of the characters while they're making the choices. If you want to talk about the dynamics of time travel in broader terms, you have to step outside that subjective POV and look at the shape of the timestream more objectively, which is akin to looking back on it after all the choices have already been made.

Also, would this model still apply/look like this if the time travel wasn't "supposed" to happen? For example, in "Carpenter Street" (ENT), Daniels tells Archer that the Xindi attack on Earth wasn't part of the "original" timeline, his future faction has no records of it and the NX-01's mission to stop it happening, and the faction has no idea what the outcome is going to be like. How would such a scenario fit your model?

Again, the key is to understand that definitions are relative to your point of view. The timeline is the "original" from Archer's and Daniels's point of view, but that's relative to their own subjective experience of time. It's not a cosmic absolute. From the perspective of a different observer with a broader view of the multiverse -- which is the perspective we need to adopt if we want to analyze the dynamics of the time travel -- all those alternate paths are simply part of the graph, and characters see them as "original" or not based on their own subjective journeys and which ones they perceive first.

I was actually referring to the Picard and Guinen example from "Time's Arrow." Does your thoughts on "paradox" being the wrong term apply to that, too?

Of course. I was talking about self-consistent time loops in general.

I thought predestination paradoxes were called "paradoxes" because of the way that the effect triggers the cause, basically reversing cause and effect.

That is the exact point I already made -- that the writers using that term assumed that the inversion of conventional cause and effect was a paradox, but they were wrong to think that, because the scientific reality of it is that it's the opposite of a paradox. It's important to let go of our everyday preconceptions of causality, time, and space when we're talking about things like time travel, because those are situations that lie outside our everyday experience and thus our conventional intuitions don't apply. Which is why we have science and math to let us calculate what would actually happen in situations where our assumptions and expectations fall apart.

Hypothetical: say that the "many worlds" theory wasn't usable. What do you think would be the best alternative explanation?

I don't understand the question.

Wouldn't the many worlds theory also make predestination paradoxes impossible? That scenario depends on the time travelers staying in their own timeline, not going off into a new one.

Why do people always assume that every time travel has to happen in the exact same way? That is not how physics works. There are countless examples of the same physical laws producing very different outcomes when the initial conditions are different. The same cosmological processes that produce stars also produce planets and asteroids and comets. The same geological processes that create continents also create ocean basins. The same genetic and environmental mechanisms that led to the evolution of mammals also led to the evolution of birds. So why can't the same laws of time travel produce self-consistent loops in some conditions and branching timelines in others? I don't for the life of me understand why people jump to such a bizarre conclusion.

Indeed, according to one interpretation, quantum physics pretty much requires both to happen in any time travel. Quantum physics is probabilistic, after all. So quantifying a particle's path through time requires summing all its possible paths. In short, if there's a chance that it will cause its own past and a chance that it will alter its own past, then both outcomes will happen. To put this in human terms, let's say you go back in time to kill Hitler or whatever and you have a 50/50 chance of pulling it off. So this will result in a timeline where you fail to kill Hitler and everything stays the same, and a timeline where you kill Hitler and everything is different. It's not a choice between a loop and a parallel; both of them are required to happen.

In a lot of Trek time travel shows, the timeline is shown changing around the characters (like in "Yesterday's Enterprise" [TNG]). Would that still happen in a many worlds time travel model? Because, if the time travel creates an alternate timeline, wouldn't the "original" root timeline be unaffected (except for the missing time travelers), while the new timeline is the one that the time travelers mess up?

Scientifically, this is gibberish. It wouldn't happen that way. As I've already told you before (I'm getting sick of repeating myself), what I've done in my DTI novels is to rationalize this absurd fictional conceit by positing that the parallel timelines reconverge once time catches up with the moment of the original time travel. I've discussed the physics of this in Watching the Clock and my online notes to same, so I refer you to those.