Final answer:
The subject's relationship with friends in Catherine Doty's poem 'Momentum' reveals the theme of human emotions and interactions, showing the influence of personal connections on one's perception of life.
Step-by-step explanation:
In Catherine Doty's poem Momentum, the subject's relationship with their friends contributes to the development of the poem's theme by providing a lens through which the reader can understand the nuances of human interaction and the complexities of friendship. The shared experiences and emotions conveyed through these relationships offer insights into the theme of human existence, reflecting on essential human emotions like love, and highlighting how these relationships shape one's understanding of the world. As the poet explores these dynamics, the reader gains a deeper appreciation for the ways in which personal connections can both reflect and influence one's perception of life.