The photographs are graphic, the shapes so beautiful. Sometimes magic seems to bounce out of nowhere. "One day I was working out how to light a dark cabin to show the riveting and metal work. All of a sudden I saw a white ball move across the room, like a lit piece of dust but the size of a tennis ball. It was spooky: only the slightest light filtered into the room, not enough to do that. I told a Swedish engineer on board and, to my surprise, he showed me pictures of a light ball moving across the same cabin!”