# Mechanical Systems Mechanical systems consist of those systems that follow the laws of physics. They behave in highly predictable ways. If we know the detailed structure of the system, we can predict with a high level of certainty the behavior of the system’s processes. The flow of water provides an excellent example of a mechanical system. We can say with almost absolute certainty that water from a small rainstorm on the East slope of the Rocky Mountains will ultimately arrive in the Gulf of Mexico. Even with the mechanical system, however, we cannot predict all the behavior precisely simply because we don’t have the capability of knowing all the details of the system structure. No one has mapped out the exact location of every rock and stone in the streams from the Rockies to the Mississippi. It will require this level of detail to predict the behavior of the system in detail. [[Complex living systems]] present an additional set of complications.