When I was very young, around three or four, I lived with my parents in a fourth-floor apartment in Brooklyn. From our window, we had a wide view of the city. I have a memory from that time that has always stayed with me. Floating above the buildings, I would see shapes, almost like letters or symbols, suspended in the air. They were enormous, about the height of a two-story house, stretching across what felt like an entire city block. It looked as though a sentence had been written across th...