Bigger things than humans

Yesterday, as my plane taxied into Sydney Airport, I was struck by how small humans are compared to some of the things we have created. Everything in the airport fits together - the planes, the runways, the terminal building - and then there are these bizarre-looking little figures running around in the midst of it all. They looked incongruous, out of place, and incredibly fragile compared to the huge world of architecture and machinery. Will we one day construct a structure that is so huge and complicated that we will lose control of it? Some would say that we already have. The stockmarket is one example that springs to mind. It was conceived and created by humans, but does anyone really understand how it works? No one can control it with any certainty, and it has the power to cause great human suffering in the form of recessions and depressions. Will the monster break out of control one day?