These are great images for getting a feel for the relative sizes of celestial bodies, but... the ending is just dumb. No one ever thought humanity was important because of humans' size! Let's take, say, a medieval Christian. Do you think she wasn't aware of the existence of elephants and whales? That she didn't realize that she was pretty small compared to the Alps? Do you think she didn't know that the number of ants or grains of sand dwarfed the number of humans? Why would discovering even bigger things, or more numerous things, make any difference at all to her view about being "the center of the universe"?