Dimensions and physics and moving through the invisible dimension of time.
Time traveling between wars. The inevitability of global conflict in the late 19th century. The inevitability of nuclear apocalypse in 1960. The inevitability of humanity overreaching in manipulation of the natural world in 2002. Really large explosions, nuclear and otherwise. Krakatoa vs Tsar Bomba. The year without a summer.
Time traveling across geological time scales. Tracking in relative space and over miles across the planet’s surface. “Time and space machine.” Staccato time travel.
Human evolution and selective pressures. Humans as cattle. Inefficiency in turning sunlight into steak. Maintaining 19th-century English over millennia.
Single-timeline self-consistency. Time travel victory strategies.
What books would you bring with you to repair future society?