|Debut||Manga: "The Terrifying Message"|
Anime: "Mystery Revealed"
When traveling back in time, the Time Machine creates a new timeline that branches off from its original one at the moment in time where the Time Machine arrived. Thus it is not possible to "change" the past, in the sense that one's present will change. Any change done in the past will be reflected in a new timeline. However, when traveling back to the future, the Time Machine will go back to its original timeline, and not to the new timeline's future. If it is used to travel again back to the past to a point after a previous trip, the Time Machine will go to the newest timeline.
According to Future Trunks, the Time Machine uses up a lot of energy, so it can carry barely enough power for two trips in time. Thus, it is generally used to travel in time, and then to go back to the present. Recharging the machine takes a lot of time, too. It seems that the only way to recharge it is in Future Trunks' own time.
Future Trunks uses the Time Machine to go to the past to warn the Z Fighters about the androids. Because of the way the machine works, Future Trunks timeline did not change at all (see alternate timeline for more details). Future Trunks went back not to change his history, but to learn of any weaknesses the androids may have; that way, he could return to his time and manage to defeat the androids there. Future Trunks used the machine again to go back and help the Z Fighters when the androids made their appearance.
In Future Trunks' original timeline, after Future Trunks returns from his second trip to the past and his deactivation of Future Android 17 and Future Android 18, Cell killed him and stole the Time Machine. He did it in order to go back in time to absorb the androids in a moment in time where they still existed. This essentially creates four timelines; the fourth one, which is never seen, involves Future Trunks going back, but, instead of training in the Hyperbolic Time Chamber, he finds the blueprints to the Androids. Bulma later crafts a remote control that deactivates them and leaves them helpless, and Future Trunks takes that controller back to his time to destroy the androids. Since he did not train in the Hyperbolic Time Chamber, Future Trunks was not strong enough to kill Cell, leading to Cell killing him and taking the Time Machine, thus creating the Cell Saga.
In order to fit inside the machine, Cell had to revert back into his egg form, in which he barely had time to press the button to send him back to the preset time. After arriving to his destination, Cell burns a hole in the hatch and abandons the stolen Time Machine, which is later photographed by a Capsule Corporation satellite. Bulma shows the photograph to Future Trunks who decides they should check it out. They find the Time Machine and Cell's shed Cocoon. Future Trunks realizes it is same as his Time Machine (as it has the word "Hope!!" written on its side). Future Trunks presses a button capsulizing it and likely took it back with him to his timeline to prevent anyone from misusing it (or reverse-engineering its technology).
In the game Dragon Ball Z: Goku's World, during the 10 days prior to the Cell Games, Future Trunks, Goku, Gohan, Krillin and Bulma uses the Time Machine to travel back in time from Goku and Krillin's training under Master Roshi to the group's first encounter with Cell.
Other Time MachinesEdit
During the movie Dragon Ball Z: Wrath of the Dragon, Bulma creates a Time Machine for Tapion to allow him to return to Planet Konats in the past. It is nearly identical to the one Future Trunks used (its design was likely based on Future Trunks' Time Machine). According to the Japanese dialogue, Bulma tells Trunks he can use another Time Machine to visit Tapion any time he wants.
In a promotional movie for Dragon Ball Heroes, the Saiyan Hero Beat and the Saiyan Heroine Note use Time Machines to go back in time and attack Frieza's remaining soldiers while Super Saiyan Goku is fighting Frieza on Namek.
Dragon Ball OnlineEdit
Redesigned Time Machines appear in the computer game Dragon Ball Online. The game features "Time Machine Missions" where players travel back in time and take part in notable aspects of the Dragon Ball history. The game's main antagonist, Miira, also plans to use a Time Machine to go into the past and steal Goku's DNA.
- Future Trunks
- Bulma (in the game Goku's World)
- Goku (in the game Goku's World)
- Gohan (in the game Goku's World, and in Dragon Ball Z: Supersonic Warriors 2)
- Krillin (in the game Goku's World)
- Players in Dragon Ball Online.
- Future Android 17 (in the video game Supersonic Warriors)
- Future Android 18 (in the video game Supersonic Warriors)
- Android 16 (in the Affectionate Android What-If Saga of Budokai Tenkaichi 3)
- The word "Hope!!" is written on the side of the machine by Bulma, emphasizing that it was hope for their world.