Why Future Trunks Can Never Go Home
The Fixed Timeline Principle explains why Trunks' time machine keeps creating new branches instead of returning him to his own past.
The Fixed Timeline Principle
Once a timeline's future is resolved, you can't land in it. A time machine that tries to arrive in a fixed past doesn't change history — it spins off a copy, a brand-new branch.
Knowledge doesn't branch — the machine does
Simply knowing the future never creates a new timeline. Only the physical arrival of the time machine into a fixed past branches reality.
Why Trunks lands in copies
When Trunks travels back, his home timeline's past is already fixed, so he can't truly return. Each trip deposits him in a fresh branch — which is how copies like T2, T3 and T4 come to exist.