The time submarine is designed for cosmic exploration, specifically to observe the future of the universe and validate various fundamental physics models, including the nature of dark energy and the ultimate fate of the universe.
The submarine uses a particle accelerator to inject dark energy, creating buoyancy that allows it to dive into the depths of cosmic time, effectively moving through the future by exceeding the flow of time.
The merger of the Andromeda galaxy with the Milky Way is observed, which is predicted to occur 31 years from the starting point of the journey. This event leads to the formation of a massive elliptical galaxy.
The Sun enters the red giant phase, expanding dramatically and eventually shedding its outer layers, leaving behind a white dwarf that will cool and crystallize into a carbon-based giant crystal.
The universe continues to expand indefinitely, with dark energy eventually tearing apart all matter, including atomic nuclei, in a process known as the Big Rip. However, this model is later disproven, and the universe's complexity gradually decreases until all matter is isolated and consciousness ceases.
The final consciousness, possibly the last remnant of the Milky Way's civilization, chooses not to destroy the travelers, possibly out of pity or a recognition of lost potential and hope. This encounter leaves a profound impact on the travelers.
The billionaire, Ted, is driven by a desire to challenge the inevitable fate of the universe, seeking to find a way to preserve life and consciousness despite the universe's ultimate decline. He believes that humanity can find a way to escape extinction.