Raising her hand, Louisa answered, "We need to study Astronomy, sir, because of the absolute mutual cycle of affection in the universe." A fancy way to say everything affected everything. "Planets, stars, comets and everything else outside our planet has an effect, even if it was a small one, on us and our magic in particular."

... oh and, "However, Astronomy has nothing to do with duck feet." Stressing on the last two words as she shot a pointed look at Daichi who was basically the reason they were wearing those silly slippers.