The novel relies on two high-concept premises, both thoroughly explored in fiction. The first is that of time travel, specifically stable time loops. Novels such as Harry Potter and the Prisoner of Azkaban by J. K. Rowling and The Time Traveler’s Wife by Audrey Niffenegger, as well as the film Primer, demonstrate this model of fictive time travel: Time travel cannot change the future, and actions that result in a change are impossible to complete. In Sea of Tranquility, the Time Institute enforces stable time loops to ensure its own existence, thus allowing it to continue policing time travel. This model of time travel is considered harder science fiction, or more in line with scientific-seeming methods of speculative fiction, despite time travel itself being, by definition, unscientific.

On the other end of the spectrum is so-called “anything goes” time travel, modeled by media such as Back to the Future, The Man in the High Castle, and The Umbrella Academy. This type of media has more abstract rules, as time is changeable, but allow greater freedom for time travel to change the outcome of events. These rules often include not meeting oneself in time (the act that creates the anomaly in Sea of Tranquility), not creating “paradoxes,” and not changing the timeline in specific ways.