What Future Trunks didn't do

[Cetra]

1. With all that brilliance he and Bulma were blessed (especially Bulma) they could have either borrowed the Dragon Balls from our Goku and restore their own planet as well as revive the people who died. And with the more powerful Dragon Balls that were made after Freezer's death they couldn't probably just have revived multiple people but actually also people that were death longer than one year (why not if the Elder Namekian says he made them more powerful? and in case of Dende's Dragon Balls it is not like he also cannot make his Dragon Balls stronger as he was able to give him certain powers when he restored Shenlong). Later he could have brought the Dragon Balls back to them.
or
2. Trunks saw Goku teleporting. He could have asked Goku "do you have 10 minutes for me to teach me how to do that?". Then he only would have needed to contact King Kai in his home timeline (even if he for some reason didn't know him he could have learned from his existence and ki in Goku's timeline and then find his ki in his own timeline), teleported to him and find Namek from there the same way Goku did and use their Dragon Balls (who also were made stronger after the death of Freezer).

[Super Saiyan Turlast x4]

1) I don't think it's possible to use the dragon balls in an entirely different era. It wouldn't make sense, either.
2) It took Goku nearly a yr to learn Teleport. It'd probably take Trunks even longer.

[Cetra]

What makes no sense about 1? Their maker is not in that timeline but the maker of exactly those Dragon Balls is still alive. And 2 should be no problem with Goku as a teacher and Trunks has all the time he needs. He even has the Time Chamber.

[Vegeto30294]

Well Shenron is only as strong as the God who "created" him, it sounds entirely too convenient to be able to have his wishes affect another time, especially an alternate timeline.

2. If you mean Future Goku, he's already dead, and no one mentioned the Time Chamber. If you mean Present Goku, Trunks was the one who decided to disappear for 3 years, and that's assuming its easy to teach to begin with.

[Darkprince410]

1) The Dragonballs are tied to the life force of their creator, thus taking them to the future to restore his world would effectively be cutting them off from their creator, thus cutting them off from their life force. It might work if he took Dende with him, and then returned them after a year's time, but by and large the majority of Earth's population would still be dead, given the limitation that exists for Earth's dragonballs (that they can't restore a large amount of people if they've been dead for more than a year).

2) Goku excels at being able to assimilate techniques after seeing them performed. If it took him the majority of a year to learn, it'd likely take Trunks far, far longer than that. Furthermore, Trunks wouldn't have the ability to reach New Namek from Earth (if Goku couldn't, then Trunks certainly couldn't) and North Kaiou wouldn't have any knowledge of what was happening on Earth to reach out to Trunks and help him reach New Namek.

[Cetra]

Well Shenron is only as strong as the God who "created" him, it sounds entirely too convenient to be able to have his wishes affect another time, especially an alternate timeline.

This whole "as strong as someone" never made too much sense because Shen Long has knowledge and powers that the creator does not have so what exactly those levels of capability are is unknown and it is magic anyway. Also the Namekian Dragon Balls were storywise very "convenient" when Goku was like "oh, crap, Shen Long can only resurrect one person per wish!" and the Elder was just like "Ha, ha, ha. Not anymore as awesome as I am"

2. If you mean Future Goku, he's already dead, and no one mentioned the Time Chamber. If you mean Present Goku, Trunks was the one who decided to disappear for 3 years, and that's assuming its easy to teach to begin with.

I am talking about our Goku. The scenario where Trunks has already met him and thinks "huh, this guy cannot only save his own timeline but mine too by teaching me how to teleport". I do not understand what you mean with the last part though and as said, it is not like Trunks has no time. Technically Goku could tell him or show him King Kai and he learns the teleportation - probably even finishes it alone when he is at home as he no longer needs Goku - and then visits his own King Kai.

1) The Dragonballs are tied to the life force of their creator, thus taking them to the future to restore his world would effectively be cutting them off from their creator, thus cutting them off from their life force. It might work if he took Dende with him, and then returned them after a year's time, but by and large the majority of Earth's population would still be dead, given the limitation that exists for Earth's dragonballs (that they can't restore a large amount of people if they've been dead for more than a year).

I have already answered that actually excluding he could take Dende with him which would also be an idea.

2) Goku excels at being able to assimilate techniques after seeing them performed. If it took him the majority of a year to learn, it'd likely take Trunks far, far longer than that. Furthermore, Trunks wouldn't have the ability to reach New Namek from Earth (if Goku couldn't, then Trunks certainly couldn't) and North Kaiou wouldn't have any knowledge of what was happening on Earth to reach out to Trunks and help him reach New Namek.

There is no "he would have no knowledge". King Kai would know from the moment Trunks visits him and tells him why he is here. And he would be able to reach King Kai because he already knows King Kai's ki from the other time. And the thought of Trunks needing more time is answered in the other posts. Technically Trunks could have used the time during the Cell games break to learn in the chamber while he musn't go over the limit of how long he may stay in the chamber.

[Darkprince410]

For the second part, outside of the Room of Spirit and Time, he wouldn't be able to afford the length of time it'd take to learn the technique if it took Goku that long, because every day that passes in the present passes in the future as well. If he spends a year in the present timeline, that's a year he's missing in his timeline, thus he'd be basically handing #17 and #18 the future with no resistance whatsoever.

Besides, as said, all the Z Senshi and most all of the world's population would have been dead for longer than a year's time, thus unable to be revived by a wish. Additionally, until he defeated #17 and #18, anything he did to restore the planet could still easily be undone by them. By the time he had defeated the two and Cell, he'd be better off just helping to rebuild civilization the hard way.

[Cetra]

For the second part, outside of the Room of Spirit and Time, he wouldn't be able to afford the length of time it'd take to learn the technique if it took Goku that long, because every day that passes in the present passes in the future as well. If he spends a year in the present timeline, that's a year he's missing in his timeline, thus he'd be basically handing #17 and #18 the future with no resistance whatsoever.

He did spend that time somewhere anyway as, like I said, it was the pre-Cell games time. Outside of the room, yes. It is too long as long as he returns to his original timeline where the time has passed and didn't just travel to the point right after he left (which he doesn't as we could see, he really arrived in his own time spot where time has passed I just wanted to point that out).

Besides, as said, all the Z Senshi and most all of the world's population would have been dead for longer than a year's time, thus unable to be revived by a wish.

Like I said, I already answered that. If you can magically make a dragon stronger to give him more power to revive more people at once there should be no problem with breaking the 1 year time window of the revival (as long as they are not reborn).

Additionally, until he defeated #17 and #18, anything he did to restore the planet could still easily be undone by them. By the time he had defeated the two and Cell, he'd be better off just helping to rebuild civilization the hard way.

Except it would have been better to have an even greater civilization he could help which would have been possible with the Dragon Balls.

[Darkprince410]

For the second part, outside of the Room of Spirit and Time, he wouldn't be able to afford the length of time it'd take to learn the technique if it took Goku that long, because every day that passes in the present passes in the future as well. If he spends a year in the present timeline, that's a year he's missing in his timeline, thus he'd be basically handing #17 and #18 the future with no resistance whatsoever.

He did spend that time somewhere anyway as, like I said, it was the pre-Cell games time. Outside of the room, yes. It is too long.

Besides, as said, all the Z Senshi and most all of the world's population would have been dead for longer than a year's time, thus unable to be revived by a wish.

Like I said, I already answered that. If you can magically make a dragon stronger to give him more power to revive more people at once there should be no problem with breaking the 1 year time window of the revival (as long as they are not reborn).

Additionally, until he defeated #17 and #18, anything he did to restore the planet could still easily be undone by them. By the time he had defeated the two and Cell, he'd be better off just helping to rebuild civilization the hard way.

Except it would have been better to have an even greater civilization he could help which would have been possible with the Dragon Balls.

1) His two times in the Room of Spirit and Time were a result of him trying to train to get stronger. When it came to the time he met up with Goku after Freeza's death, he immediately went back to his own time to spend the three years in his timeline. He wouldn't want to stay in the present for that long and leave the Earth of his timeline unprotected for so long. There really just isn't any time for him to be able to.

2) We don't know though whether it's actually possible for them to extend that time, because we don't know if that's a simple limitation of the Dragonballs themselves, or if it's related to how long a spirit resides in the afterlife until it is reincarnated. Even if it is a limitation of the Dragonballs, we don't know if it's physically possible for them to be altered in that particular way. When it came to increasing the number of wishes Earth's Dragonballs were capable of, it cut the power available to each wish in such a way that the normal three wishes that were available were cut down to two when reviving multiple people. With Muuri's Dragonballs, since it's still using Porunga's template, we can reasonably assume that the ability to revive multiple people with one wish resulted in a decrease in their effectiveness in some other sense. In short though, since we don't know if it's physically possible for that one year limit to be extended, we can't assume that it's possible to change that limit.

3) Helping to rebuild civilization the hard way would help to bring the remaining population together as a whole, and would be far more beneficial in the end than just wishing for all material things to be restored. You would be able to rebuild civilization in a way that best suits who all remains, rather than thrusting the "old ways" back at people that haven't lived that way for many, many years.

[Cetra]

1) His two times in the Room of Spirit and Time were a result of him trying to train to get stronger. When it came to the time he met up with Goku after Freeza's death, he immediately went back to his own time to spend the three years in his timeline. He wouldn't want to stay in the present for that long and leave the Earth of his timeline unprotected for so long. There really just isn't any time for him to be able to.

I already told you pre-Cell games = the break (10 days plus the time before where he already trained in the room though at that time Goku was about to cure from his heart virus so either he should have told him first steps when he visited him for the first time or after his first time chamber adventure). Please pay attention. I know he returned back home. But at that time he wasn't. And if he could have known it saved his own planet he surely would have combined his training with learning to teleport.

2) We don't know though whether it's actually possible for them to extend that time, because we don't know if that's a simple limitation of the Dragonballs themselves, or if it's related to how long a spirit resides in the afterlife until it is reincarnated. Even if it is a limitation of the Dragonballs, we don't know if it's physically possible for them to be altered in that particular way. When it came to increasing the number of wishes Earth's Dragonballs were capable of, it cut the power available to each wish in such a way that the normal three wishes that were available were cut down to two when reviving multiple people. With Muuri's Dragonballs, since it's still using Porunga's template, we can reasonably assume that the ability to revive multiple people with one wish resulted in a decrease in their effectiveness in some other sense. In short though, since we don't know if it's physically possible for that one year limit to be extended, we can't assume that it's possible to change that limit.

That is what i am trying to say. We don't know it so it very well is possible and thinking how Shen Long had an advantage over the first seen version of Polunga we can assume he might be able to do some other crazy stuff as well (and Polunga too as he was modified to revive multple people like Shen Long can but first he couldn't). Normally the souls are reborn when they are finally clean but some people actually are allowed to just stay who they are so while some earthlings might be reborn already as a fish at least the Z warriors (Vegeta probably not, who knows) were still existent in the afterlife.

3) Helping to rebuild civilization the hard way would help to bring the remaining population together as a whole, and would be far more beneficial in the end than just wishing for all material things to be restored. You would be able to rebuild civilization in a way that best suits who all remains, rather than thrusting the "old ways" back at people that haven't lived that way for many, many years.

"The hard way" would not change the fact that most of them are dead and except Goku in Z and Piccolo in GT no one of them wanted to stay dead (Tenshinhan only decided to stay because he didn't want to leave Chao Zu). This "they must depend on other things than just the Dragon Balls" is fine and all but definitely not in a world full of ruin and Trunks would like to get back the others as well. He even mentioned, they couldn't use the Dragon Balls because of Piccolo and Kami's death so that was considerable. And even if they revive the people possible they could still work the hard way.

[Darkprince410]

1) Again, there's not enough time. During those days of rest, he, Vegeta, and Piccolo were constantly using the Room of Spirit and Time to grow stronger. Their immediate concern was defeating Cell, so their time in there was based on that.

2) The only people that have been shown to retain their bodies in the afterlife were those souls that had been granted permission by Enma, either due to their good deeds in life (Goku, Piccolo, etc) or because he foresaw it'd be worthwhile to keep the body around (Vegeta). Other than that, dead individuals exist solely as disembodied souls residing in Heaven or Hell until they're cleansed and reincarnated. So outside of the Z Senshi, basically the entire Earth's population would be in line to be reincarnated. Additionally, there's no real precedent for how the Z Senshi would act in that situation. When they died, most all knew they'd be revived eventually, or chose not to be revived by any means. Given that it'd be many, many years before Trunks would have been able to acquire the Dragonballs to be able to restore them, by that point they might have accepted their fates to remain in the afterlife and train.

And again, we don't know if that one year time limit is based on the Dragonballs themselves, or if it's related to how long a soul can remain in Heaven or Hell before it is cleansed and reincarnated. It's very possible that after a year's time, they're cleansed and reincarnated as someone/something else, and nothing the Dragonballs could do could alter that.

3) Trunks said that about Piccolo's death and the inability to use the Dragonballs to explain why they hadn't been used then, when it was available for them to be brought back to life to help fight. Goku wouldn't be able to be brought back regardless, so it's possible that a number of the other Z Senshi close to Goku wouldn't want to leave either.

[Marco Polo]

Future Trunks seems to develop a different philosophy than the Z Fighters from our timeline. I think he just accepts that dead people should stay dead and that the living should move on. When he returned to his timeline he killed the Androids and Cell that's it. He's moving on.

Or you can choose to assume that he did get help from our Goku, offscreen, at some point between the end of the Cell Saga and the start of the Buu Saga. I mean it's not like it would be a very interesting set of events to show anyway. Maybe Toriyama simply skipped it because it's not interesting.

[NitroEX]

Something about taking the dragonballs with him to another time doesn't sit right with me. All I can imagine is them turning into stone once he time travels since there is no creator in his time.

The only way I could see that working is if the creator went with him but there'd be no way for him to fit inside the machine with Trunks.

[Hitiro]

Doubt the dragonballs will work in another time. At least not without the creator in that time.

Though Trunks only Gohan will be able to come back alive in his timeline if he used Dende's dragonballs. The balls are still stuck at the "revive-once" limit. As such, Piccolo, Vegeta, Chaotsu, Tienshinhan, Yamcha and Kuririn wouldn't be able to come back. Though Gohan would be be. Does the virus Goku gets count as a natural death? If so he shouldn't come back either.

[Darkprince410]

Doubt the dragonballs will work in another time. At least not without the creator in that time.

Though Trunks only Gohan will be able to come back alive in his timeline if he used Dende's dragonballs. The balls are still stuck at the "revive-once" limit. As such, Piccolo, Vegeta, Chaotsu, Tenshinhan, Yamcha and Kuririn wouldn't be able to come back. Though Gohan would be be. Does the virus Goku gets count as a natural death? If so he shouldn't come back either.

Tenshinhan, Yamcha, and Piccolo would also be able to be revived by them, since they were all wished back using Namek's Dragonballs when they were still on Earth. Vegeta however was revived by the wish to kill all those killed by Freeza and his minions, and both Kuririn and Chaozu had been revived in Dragonball, so they wouldn't be able to be revived.

[Hitiro]

Doubt the dragonballs will work in another time. At least not without the creator in that time.
Tenshinhan, Yamcha, and Piccolo would also be able to be revived by them, since they were all wished back using Namek's Dragonballs when they were still on Earth. Vegeta however was revived by the wish to kill all those killed by Freeza and his minions, and both Kuririn and Chaozu had been revived in Dragonball, so they wouldn't be able to be revived.

Oh yeah, completely forgot about that. I had a derp moment.

[SilverArmada]

Trunks traveled from 784 to 764 on his first trip, this was where he arrives, kills Frieza, talks to Goku, etc. He's 17 at the time. In the manga, (I can't remember where and I don't have it in front of me right now) he mentions that it takes 8 months to charge the time machine, so as soon as it is charged again he travels back from 785 to 767, which is after the three years of training everyone does before the androids appear. Now, Trunks could have stayed in the past for those three years and trained with everyone, fought the androids, etc. and still returned home minutes after he initially left, but he chose not to do that. We don't know why. While time would pass equally when he is in the past as it would in the future while he is gone, Trunks has the ability to travel back to any point in time, likely a few minutes after he initially left so he doesn't end up "losing" any time in the future.

The idea that Trunks should have had Goku teach him shunkan idou is tenuous. It took Goku a year (or more) to learn it, and that was all he was focused on learning at the time. If Trunks stayed in 764 to train with everyone, Goku would have time to teach him, but everyone would be more focused on training to fight the androids. And I doubt Trunks would see the value in learning the technique instead of just training to become strong enough to defeat the androids outright.

Taking the dragonballs from the past to the future presents a couple of issues. We have no reason to believe they can travel through time and still function successfully, whether their creator is there or not. For all Trunks and Bulma know, doing something like that could have horrible ramifications that they can't anticipate. Trunks's trip to the past the first time is the very first time he and Bulma use the time machine and even they don't know what to expect. They want to destroy the androids in their time but Trunks took care to make sure Bulma and Vegeta didn't know who he was, in case he jeopardized his own existence - this shows that he and his mother weren't sure if the timelines were separate universes (how they are portrayed in canon) or not. So given the possibility that the timelines are not entirely separate universes, they needed to be careful to not do anything that could warp reality or destroy everything.

And lastly, to the issue of reviving people with the dragonballs (assuming it's even possible via whatever method you choose): even if Trunks and Bulma could use the dragonballs to revive everyone, would they? By the time Trunks defeats the androids, most of the Z fighters have been dead for nearly 20 years. I could see them reviving Gohan, but I think they would prefer to let everyone else stay dead. And really, would any of those folks want to be revived? Besides Vegeta who probably went to hell. Who wants to be brought back to life 20 years later to a world that has less than 100k people left. The world was destroyed and basically a dump - would Bulma and Trunks want to bring back any of Bulma's friends for that? I'm assuming that people who have been dead more than one year can't be revived as their soul has been cleansed/reincarnated/whatever. So maybe there are a few thousand humans that can be revived, which would be helpful, but wouldn't completely fix everything that had been destroyed. Maybe a better wish would be to restore all of the broken infrastructure (buildings/roads/items/etc.) destroyed by the androids, I don't know. But I don't see how bringing the dragonballs to the future magically restores everything.

[Cetra]

Trunks traveled from 784 to 764 on his first trip, this was where he arrives, kills Freeza, talks to Goku, etc. He's 17 at the time. In the manga, (I can't remember where and I don't have it in front of me right now) he mentions that it takes 8 months to charge the time machine, so as soon as it is charged again he travels back from 785 to 767, which is after the three years of training everyone does before the androids appear. Now, Trunks could have stayed in the past for those three years and trained with everyone, fought the androids, etc. and still returned home minutes after he initially left, but he chose not to do that. We don't know why. While time would pass equally when he is in the past as it would in the future while he is gone, Trunks has the ability to travel back to any point in time, likely a few minutes after he initially left so he doesn't end up "losing" any time in the future.

For the reason, that while it is his own timeline it would not be the home point of his timeline. We exist even infinite times even on one and the same timeline (this explanation has nothing to do with alternate universes) as our past and future selves (which we have infinite times even on one timeline as past and future moments cannot be counted) are not us because of our consciousness not being one (actually that is very obvious as we are always our very own present self). So if he wanted to get exactly to his home and not only to his own on his timeline without caring at which spot he must have chosen to arrive at the point where exactly the same amount of time has passed. Some people might not care about that in stories "because it is still the others as it is one timeline" but if you really want to get to the time of the timeline from which you came you need to calculate the same time that has already passed there since "your original home time spot" has already moved that much on the timeline.

The idea that Trunks should have had Goku teach him shunkan idou is tenuous. It took Goku a year (or more) to learn it, and that was all he was focused on learning at the time. If Trunks stayed in 764 to train with everyone, Goku would have time to teach him, but everyone would be more focused on training to fight the androids. And I doubt Trunks would see the value in learning the technique instead of just training to become strong enough to defeat the androids outright.

It is far from being tenuous. Trunks wanted Goku to have another timeline exactly because he knew his own timeline was so bad. So of course helping his own timeline from his own present point were he is home is something he also wants to do. There is no reason why he would want things to stay the way they are, which is why he destroys the Cyborgs in the first place. Of course he wants peace. There is also no reason to believe that Trunks would not want to revive as many people as possible.

Taking the dragonballs from the past to the future presents a couple of issues. We have no reason to believe they can travel through time and still function successfully, whether their creator is there or not.

That goes for the opposite way as well. We have no really convincing reason to believe it does not work. They are Dragon Balls, as I already mentioned. And even if they don't work without Dende, Trunks could have taken a second Time Machine within a capsule and told Dende "there you jump to the other branch, I have already prepared the machine for you".

So given the possibility that the timelines are not entirely separate universes, they needed to be careful to not do anything that could warp reality or destroy everything.

That never is a possibility. That is not how a closed circuit works. Whatever happened, happened. This whole retconning your own past is a causality paradox which cannot occur in the first place as you cannot make your own reason for the change and initiating it erase, which means it is not being possible to change something on one and the same time line and Trunks knew that. You cannot destroy something with a paradox because the fact that you exist and that time causality works in a circuit naturally stops a paradox from happening. Trunks exists at one point and that means he has not and will not destroy his existence because he can't. If he would have he wouldn't have been there in the first place in the required situation - which also would not exist - to do it which means he can't do it. It does not work the way some movies show with retconning and forgetting and all because that has no full logicallly closed order of events meaning it can't happen. He even told Gohan what he does does not change his own time. If he would have travelled back into the past again and destroyed the Cyborgs it would not have meant anything for his time line and only caused another time split if anything which has nothing to do with a change. He was very well aware of the fact. People conveniently say "change time" as well if time splits up but actually it is no change because it has nothing to do with the other timeline so the term is misused. And as said, Trunks knew how these things work. Most likely because of Bulma.

And lastly, to the issue of reviving people with the dragonballs (assuming it's even possible via whatever method you choose): even if Trunks and Bulma could use the dragonballs to revive everyone, would they? By the time Trunks defeats the androids, most of the Z fighters have been dead for nearly 20 years. I could see them reviving Gohan, but I think they would prefer to let everyone else stay dead. And really, would any of those folks want to be revived? Besides Vegeta who probably went to hell. Who wants to be brought back to life 20 years later to a world that has less than 100k people left. The world was destroyed and basically a dump - would Bulma and Trunks want to bring back any of Bulma's friends for that? I'm assuming that people who have been dead more than one year can't be revived as their soul has been cleansed/reincarnated/whatever. So maybe there are a few thousand humans that can be revived, which would be helpful, but wouldn't completely fix everything that had been destroyed. Maybe a better wish would be to restore all of the broken infrastructure (buildings/roads/items/etc.) destroyed by the androids, I don't know. But I don't see how bringing the dragonballs to the future magically restores everything.

Don't you think it is a bit ironic to say you don't see how the Dragon Balls magically restore everything? Also, if they would have gotten the Dragon Balls it would have meant more wishes anyway.

[SilverArmada]

For the reason, that while it is his own timeline it would not be the home point of his timeline. We exist even infinite times even on one and the same timeline (this explanation has nothing to do with alternate universes) as our past and future selves (which we have infinite times even on one timeline as past and future moments cannot be counted) are not us because of our consciousness not being one (actually that is very obvious as we are always our very own present self). So if he wanted to get exactly to his home and not only to his own on his timeline without caring at which spot he must have chosen to arrive at the point where exactly the same amount of time has passed. Some people might not care about that in stories "because it is still the others as it is one timeline" but if you really want to get to the time of the timeline from which you came you need to calculate the same time that has already passed there since "your original home time spot" has already moved that much on the timeline.

None of this matters because this is not how time travel is portrayed in canon. You can argue that it's nonsensical for Toriyama to have written it this way, but it is known in canon that Trunks did not wait three years in the future before traveling back to the past for the second time.

It is far from being tenuous. Trunks wanted Goku to have another timeline exactly because he knew his own timeline was so bad. So of course helping his own timeline from his own present point were he is home is something he also wants to do. There is no reason why he would want things to stay the way they are, which is why he destroys the Cyborgs in the first place. Of course he wants peace. There is also no reason to believe that Trunks would not want to revive as many people as possible.''

What you are saying here does not address my point about why Goku would not have taught Trunks the shunkan idou.

That goes for the opposite way as well. We have no really convincing reason to believe it does not work. They are Dragon Balls, as I already mentioned. And even if they don't work without Dende, Trunks could have taken a second Time Machine within a capsule and told Dende "there you jump to the other branch, I have already prepared the machine for you".

Where is Trunks going to get a second time machine? It took Bulma years and about everything she had to build one. Is he supposed to jump around to other universes and steal equipment from them, thus disrupting those timelines as well? As for the dragonballs - they cannot fix everything and the dragon cannot DO everything. There are limitations. If you're going to make the case that a character made a mistake by not doing X then you should have some proof that X was possible.

That never is a possibility. That is not how a closed circuit works. Whatever happened, happened. This whole retconning your own past is a causality paradox which cannot occur in the first place as you cannot make your own reason for the change and initiating it erase, which means it is not being possible to change something on one and the same time line and Trunks knew that. You cannot destroy something with a paradox because the fact that you exist and that time causality works in a circuit naturally stops a paradox from happening. Trunks exists at one point and that means he has not and will not destroy his existence because he can't. If he would have he wouldn't have been there in the first place in the required situation - which also would not exist - to do it which means he can't do it. It does not work the way some movies show with retconning and forgetting and all because that has no full logicallly closed order of events meaning it can't happen. He even told Gohan what he does does not change his own time. If he would have travelled back into the past again and destroyed the Cyborgs it would not have meant anything for his time line and only caused another time split if anything which has nothing to do with a change. He was very well aware of the fact. People conveniently say "change time" as well if time splits up but actually it is no change because it has nothing to do with the other timeline so the term is misused. And as said, Trunks knew how these things work. Most likely because of Bulma.

Trunks told Gohan that he could not change the future by changing the past because he knew this AFTER traveling back into the past the first time. Regardless of your point about a closed circuit, the CHARACTERS demonstrated that they did not know that could NOT happen.

Don't you think it is a bit ironic to say you don't see how the Dragon Balls magically restore everything? Also, if they would have gotten the Dragon Balls it would have meant more wishes anyway.

No - the dragonballs cannot do everything imaginable, this is demonstrated in the series on multiple occasions. Do they accomplish incredible things? Yes absolutely. But only under specific circumstances.

[Cetra]

None of this matters because this is not how time travel is portrayed in canon. You can argue that it's nonsensical for Toriyama to have written it this way, but it is known in canon that Trunks did not wait three years in the future before traveling back to the past for the second time.

There is a difference but I am afraid this would take too long and go off topic. If you want to talk about that we can discuss that via PM.

What you are saying here does not address my point about why Goku would not have taught Trunks the shunkan idou.

I very well read your post about training and Goku taking the time to teach him and all that stuff. That does not change the fact that I already mentioned Trunks could have done both.

Trunks told Gohan that he could not change the future by changing the past because he knew this AFTER traveling back into the past the first time. Regardless of your point about a closed circuit, the CHARACTERS demonstrated that they did not know that could NOT happen.

They didn't demonstrate anything as the scenes you use for that conclusion are not unequivocal. There never was something saying that Trunks wasn't sure about paradoxes, he just first thought he was responsible for the time split while it actually was Cell's arrival and that was all.

Where is Trunks going to get a second time machine? It took Bulma years and about everything she had to build one. Is he supposed to jump around to other universes and steal equipment from them, thus disrupting those timelines as well? As for the dragonballs - they cannot fix everything and the dragon cannot DO everything. There are limitations. If you're going to make the case that a character made a mistake by not doing X then you should have some proof that X was possible.

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No - the dragonballs cannot do everything imaginable, this is demonstrated in the series on multiple occasions. Do they accomplish incredible things? Yes absolutely. But only under specific circumstances.

Why are you asking me for proof when you yourself say multiple things that cannot be proven without an unequivocal scene in the series? You are trying to disprove me with something that cannot disprove me. You just assume as well as I do that certain things could or could not be made and with magical powers and all that stuff it is no use being so persistent that certain things that are far from being that unimaginable can't happen when people can get eternal youth or be made immortal or planet's can get restored. I never said the Dragon Balls have no limits. I said they can be made stronger and there is a fact that the Dragon Balls have powers that the creator of the Dragon Balls doesn't have as well as the fact that the Dragon Balls per sé are not even really defined in their function so there is no reason to assume certain powers cannot be given as long as it is not something like "The Elder Namekian gives the Dragon Balls the power to defeat Super Xi Xing Long" or anything which is at least implied to be not possible because of the Dragon Ball creator's power. There is so much unknown about the Dragon Balls, the only thing your can say against what I say is that we don't know if that works and that is really not even something I don't say because I only say "we don't know so it could be possible" and that also implies it could be that it isn't possible but I have to talk here for the "could be" scenario. Also, where is the problem with Bulma making another time machine? She now knows how to build one that works. Or huh - maybe he just takes the one he actually took from Cell and brings it to his mother in the Alternate Future, his own time line, so she can repair it? Or he asks Shen Long for a second one instead of Kuririn wishing for 18 to have her bomb removed (which would require him to come back later again because Shen Long has just been used but at least then there is another time machine) or he could have asked Shen Long to give immediately teach him Instant Transmission so he can use it in his own time line and do then what I said in the first place? We are talking about fantasy here. The possibilites are here. You can't just talk against everything here as if those things didn't happen because they can't be as weirder things have happened in Dragon Ball and greater powers have shown to be existant. And a few steps to finally help his time line with more than destroying the Cyborgs really are not too much. If things can be restored and people revived then, it surely is worth that. And while you say "no", it doesn't make sense, because they can magically restore the world and revive people so there is no reason to believe they can't restore cities and revive people because that is one and the same (except a city not being a world but you get what I mean). They can go from "one person" to "all people included in a certain worded wish" so why would they also not be able to revive someone who is dead for longer than one year. They never said where exactly those limits to how powerful Shen Long and Polunga can be made are.