Beginning with line 5, when I heard about astronomers' study, the first bottom briefly explained the reaction of the speaker to the dry matter of the astronomy course. Shortly after the lecture began, he said he was bored and felt sick. The reason is "irresponsible" or unknown. Line 7 continues to use more sophisticated languages. The poet expressed the outside world as "a mysterious wet night sky". The beauty of this sentence is in stark contrast to the initial mathematical term list and frank facts. Pay particular attention to the word "mystery" in this line. It means that the response to nature is stronger than that provided by science, suggesting that the speaker has a deeper relationship with the star, even though he can not listen to the entire astronomer's lecture .
Each line was part of a long sentence when I heard that Learn'd astronomer consists of 8 lines. Each of the first four lines starts with "when" and looks like a list of facts, not part of a poem (although repetition is, of course, a poetic analogy). The second, third and fourth lines list the way the instructor talks about astronomy and the reaction of the audience to the discussion. The second half of the poett turns into a language from a simple language used to describe astronomer lectures. The poet uses more elegant and somewhat flamboyant words. At the end of the verse, the change of state and meaning, often intended to emphasize the meaning of poetry, is often referred to as "rotation" in literary analysis. In this case, Whitman shows his preference for learning nature in nature.