Parallel lines meet at infinity is a basic theory, I learned back in High School. I captured this from within the train. After a while the passing multitude of skyscrapers seems boring and you look to amuse yourself in other manners. Since no fun can be had inside the train (there are cameras that fine you on the spot), finding cool things outside is the only reprieve. The reflection of this parallel train running along the in the buildings lining the tracks was a cool sight. They will meet one day, but only at infinity.