If you’ve ever been on the Tube (London Underground) you’ll be familiar with the phrase “Mind the Gap!” Not only is it announced as train doors open, but it’s also written on the floor in numerous stations. To make it easy and efficient for trains to traverse the underground tube-like tunnels throughout London, some tracks are curved even in the stations. Therefore, the platforms are also curved. But train carriages are straight. Naturally, the center of each train carriage is the closest it gets to the platform but the ends of each carriage can be far away. For the sake of providing an efficient service, there is a gap. By this time…