Eternal Life in Crisis

[Hard science fiction: Frozen city, underwater abyss, huge waves, burning prairie fire, meteorite rain, ozone hole, gamma ray burst, dark forest, forest of civilization, artificial intelligence... The road of time loop, the Baitama Triangle of space delivery... Crisis after crisis, how do humans face it? Background: After experiencing the meteorite crisis, mankind finally understood the status of technology and stopped all disputes. Gathering global efforts, we built an artificial island of more than 50,000 square kilometers near the equator of the Pacific Ocean, and built an academy on the artificial island that concentrated all human science and technology... … "At some point in the future, will someone travel to the present? Like me." Yu Zixing expressed his obsession. "Your idea is good, but do you know how many theoretical difficulties you have to overcome? Grandfather's refutation, the butterfly effect... Can humans invent a time machine in the future? Or will your life span last until that time? This has also extended to many philosophical issues." Rick said. "As long as people's obsession with the future is strong enough and they work hard, they firmly believe that the future self can pass. The future can affect the present. As for those theories... As long as they can break through the universe..." Yu Zixing said. "Comparatively speaking, I think it is more likely to break through the warp engine technology." Another student said. [Hard science fiction (fast pace, lots of foreshadowing, funny but not boring, shocking scenes)]