The same sky.… The first time Kenji noticed it, he was eight years old. It happened in a neighborhood park in Yokohama. Two adults were repairing a weather sensor mounted atop a metal ladder nearly five meters high. One of them suddenly shouted down: “Hey! Throw me the camera!” Without hesitation, the other man grabbed a heavy DSLR hanging from his shoulder and tossed it upward. The camera traced a smooth arc through the summer air. The man on the ladder caught it with both hands, pointed it toward the sensor, snapped several photos, and then tossed it back down. Kenji stared in disbelief. To him, cameras were precious objects. His father carefully wrapped his own camera in padded cases and never let anyone touch it. Yet these men had thrown one through the air as casually as a baseball. The incident remained in his memory for years. ⸻ Twenty years later, Kenji was a logistics engineer working for a company developing a...