That sounds like a highly imaginative and surreal phrase, but invisible bananas and square, whispering moons aren't things that exist in the physical world to be calibrated. 

If you are working on a creative writing project, we could talk about surrealist styles in literature and art. Alternatively, if you'd like to look at something more grounded, we could discuss actual facts about the moon or how real-world scientific instruments are calibrated. What kind of topic would you like to explore today?
