ABSTRACT
Imagine that on a nice summer night you look up and see hundreds of minuscule shimmering dots of light, immersed in the most absolute darkness. There seems to be no end to it, its vastness beyond anything you can comprehend. The word “infinity” springs to your mind. An unpleasant feeling of loneliness starts to creep in. You long for company, for a sense of closeness. But there is no one in sight. Just you, stars, and darkness. You shake off these thoughts by reasoning that it’s impossible to know for sure how vast it all is. For all you can see—even if you know this can’t be right—it seems equally reasonable that the stars are plastered in some kind of celestial sphere that slowly rotates westward with the night. Maybe the cosmos is bounded by some kind of celestial dome, like an all-encompassing womb. Why not? Much cozier this way, right? Infinity is a weird concept; you can’t put your hands on it. In fact, why not add spheres to carry each of the planets and the moon as well? Better make them out of crystal so you can still see through them. There, the night sky has some order now, the cosmos is finite and it all feels much better. It’s hard for us to tolerate the unknown.
