chapter  11
14 Pages

Conditional Logic

Over a century ago, railroads were hot technology, pushing innovation and driving the economy. The buildup of rail infrastructure put tracks between cities, essentially creating a road network for trains. Unlike natural paths or roads for people, horses, and livestock, trains cannot turn by themselves from one track to another. It took the invention of the rail switch to get trains from one track to another. Eventually a network of tracks and switching junctions emerged.