In the last episode, why did Sara never consider using the transportation machine to bring the children to the USA to put them in a foster home or something? Abelia is shown in the first episode transporting multiple giant snake-like mechs using the machine, surely a dozen or so children wouldn't be so much of a problem. Abelia is seen at the very least cooperating with the group at the end, so she would likely be willing to use the machine for this purpose, having just done so for Shu. The USA is definitely in better shape than the desolate, broken-down Hellywood at the end of the series. Sara could have ensured that the kids survive in a home, (rather than having them continue living in a Crapsack World and potentially die of natural causes given the lack of resources) and also got to return to her parents and discuss the pregnancy. Sis definitely would have preferred the kids surviving over Sara trying to be a mother figure while only a few years older than the kids themselves.
Why do people insist that it's likely that the humans surviving at the end (including Sara and the children) will be killed by the sun going super nova? Sure the show is taking place at the tail end of the sun's lifetime, but once we are taking about a time scale of billions of years it's basically impossible to tell whether the remaining time of the sun's lifespan is still to be measured in days, years, or even millennia. All those time periods would be negligible in comparison to a billion years.
Just as she initially views human life as meaningless, Lala herself fails to consider how many generations can fit between now and then. People take her words a bit too literally and fail to realize that it represents a nihilistic thesis that the show eventually refutes.
How are Sara and Shu able to talk to each other? It's highly doubtful that Sara's fluent in Japanese and Shu in English, and for that matter what language does everyone in Hellywood speak? How are Sara and Shu able to speak to them?
Why don't they use the time machine to get water?
It can be assumed that the time machine requires a lot of energy to use, and the limited amount of matter it can retrieve at a time wouldn't be enough to break even.
Why don't they use the time machine to get a past version of Lala-Ru? We know she and her necklace can be sent through it cheaply enough for that to not be a problem.
