Imagine that you have to get to Grandma’s house, which, according to legend, is over the hills and through the woods, and two states away. That would be two countries away if you live in Europe. To plan your trip, you can start in one of two ways. Ignoring the fact that Google has taken away most map reading and navigation skills from today’s youth, you would get out a map and either:
- Start at your house and try to find the roads that are closest to a straight line to Grandma’s house
- Start at Grandma’s house and try to find roads leading to your home
From either direction, you will find that the road or path you seek forks, intersects, changes, meanders, and may even come to a dead end. Also, all roads are not created equally – some are bigger, with higher speed limits, and some are smaller, with more stop signs. In...