The concept of entropy from physics helps to explain apparently random disorder. Entropy is a measure of thermal energy within a system as well as of disorder or randomness. The tendency toward uniformity of energy involves the exchange of heat between colliding bodies.
Thomas Pynchon uses the concept metaphorically throughout the story in relationship to numerous dimensions of human existence and human relationships with other species, both plants and animals. Callisto understands the concept as applied to the artificial environment that he has created by keeping his apartment sealed. He seems to think that these measures will create stability, but he exposes himself to tumultuous changes through his relationship with Audrade.
Saul also applies the idea of a closed system to emotion. Specifically, he compares love to an electrical circuit, polinting out the dangers of “leakage.” If a man tells a woman, “I love you,” the two individuals are contained within “a closed circuit. Just you and she.” The emotional aspect, however, creates ambiguities that throw things off balance—“noise” that causes disorganization.
Callisto similarly considers love, which he sees as counterbalancing thermodynamics, and he considers that the universe requires both of them. Recognizing as well the limits of the closed system model, he addresses the question of loss (especially of heat). Callisto applies entropy to consumerism as it serves to equalize the consumers, through a behavior that moves people toward sameness while convincing them that their choices represent difference.