LitCharts assigns a color and icon to each theme in The Sun is Also a Star, which you can use to track the themes throughout the work.
Immigration and the American Dream
Passion vs. Reason
Interconnectedness and Destiny
Isolation vs. Connection
Summary
Analysis
Daniel and Natasha argue over which questions to choose, and Daniel insists that they can't skip the staring exercise. They choose three questions from the least intimate category, two from the medium-intimacy category, and four from the category of most intimate questions. They come up with ten questions since for one question about their mothers, Natasha insists they need to talk about their fathers as well.
Natasha's insistence that they talk about their dads as well as their moms shows that she absolutely believes that her relationships with both her parents are important and worth consideration. This, in turn, suggests that she's possibly not as isolated from her family as she'd like to think.
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Themes
Natasha checks the time and curses that she needs to go. Daniel tries to follow her through the crowds. He reasons that if he were to look for signs that he should abandon her, he'd probably find them. When he catches her at a crosswalk, Daniel decides he's not going to cut his hair, and Natasha reminds him that she's heading uptown for her appointment.
Despite Daniel's belief in destiny, he does note here that he could interpret anything he likes as being predestined. This adds a distinctly human element to the novel's exploration of destiny, and suggests that spotting destiny is in the hands of the person looking for it.
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Themes
Quotes
After a few blocks, Daniel pulls out his phone, and Natasha mocks his belief in love. Daniel encourages her to think of it as an experiment, and suggests that it's okay for researchers to experiment on themselves if it's for the greater good. Natasha laughs.
When they decide to bend scientific conventions to suit their own needs, it shows that both Natasha and Daniel are willing to compromise when it's in their own best interests.