The “entropy” of this story’s title is a difficult, slippery concept to understand. It is a term from thermodynamics—the study of the conversion of heat into energy—and refers to the parts of a system that do not work for this conversion. The term can also be used metaphorically, referring to a state of simultaneous chaos and stasis. In his introduction to Slow Learner, Pynchon admits that he himself still does not fully grasp the concept of entropy:

Because the story has been anthologized a couple-three times, people think I know more about the subject of entropy than I really do […] But the qualities and quantities will not come together to form a unified notion in my head (12-14).

The characters in Pynchon’s story likewise struggle to comprehend the concept, while also in different ways embodying it. The two main settings in the story, Meatball Mulligan’s apartment party and Callisto’s greenhouse sanctuary, represent two different sides of the entropy equation. Mulligan’s party is chaotic and becomes more so as the story continues. Strangers and desperate friends crash his party, and his apartment is laid to waste, all of which causes Mulligan, an affable-seeming hipster, no more than mild concern. Callisto’s apartment, conversely, is designed to be a harmonious retreat from the chaos that Mulligan’s party represents.