How does the free verse structure reflect the central theme of the poem:

When I heard the learn'd astronomer,

When the proofs, the figures, were ranged in columns before me,

When I was shown the charts and diagrams, to add, divide, and measure them,

When I sitting heard the astronomer where he lectured with much applause in the lecture-room,

How soon unaccountable I became tired and sick,

Till rising and gliding out I wander'd off by myself,

In the mystical moist night-air, and from time to time,

Look'd up in perfect silence at the stars.

I'm just having trouble figuring out how to answer the question because it's confusing to me

In this poem, Whitman is criticizing knowledge. As the narrator listens to a knowledgable astronomer he suddenly becomes bored. There is so much science to what he is saying ("the proofs, the figures ... charts and diagrams") but through the poem one notices that the narrator finds that there is not a truly profound meaning, what the astronomer is saying it's empty. The free verse structure reflects the same concept, in free verse, there is not a specific format, structure, style, or rhyme scheme that needs to be followed. However, the narrator is more focused on the message that he is trying to convey rather than trying to fulfill many rules and follow a rigid structure.