I didn’t have “time travel” anywhere near the top of my “next grift after AI” list. The chronomigration bubble came out of a confluence of developments; gamma ray telescopes sensitive to the 500 keV electron-positron annihilation energy allowed us to spot the inbound antimatter comet 67i/Fermi as soon as it began interacting with the solar wind. Gravity tugs brought 67i to lunar orbit, where laser ablation was used to direct a stream of antimatter dust onto fuel pellets (just moon rocks, in fact). The plume of energy liberated by quantum annihilation acted as a giant rocket motor, slightly perturbing the moon’s orbit in such a way to tug the earth farther enough away from the sun to cool the climate. It will take four hundred centuries, which is where the time travel (also facilitated by the matter/antimatter energy fountain) comes in. If you can afford the fare, you can deposit one dollar in a savings account, blip out of our climate ravaged world and arrive rich in the clean, comfortable future. No, you cannot deduct the cost from your future fortune, it doesn’t work like that. It doesn’t work at all. The kind of person who would take this offer can’t be expected to know the difference between a time portal and a disintegration field. And they just won’t believe you when you warn them.