Unable to sleep after the others had drowsed off, I crawled out of the tent and lay on the ground, looking at the sky. Now and then, a shooting star would trace a bright arc across the heavens. The longer I watched, though, the more nervous it made me. There were simply too many stars, and the sky was too vast and deep. A huge, overpowering foreign object, it surrounded me, enveloped me, and made me feel almost dizzy. Until that moment, I had always thought that the earth on which I stood was a solid object that would last forever. Or rather, I had never thought about such a thing at all. I had simply taken it for granted.