A state machine is basically a model of computation which helps one analyze the effects of input on a system. This system can remain in different states throughout its life cycle though in only one state at a time. It can transition from one state to another depending on some input. Every state machine has a start state and it progresses from there to other states eventually leading to an end state. Note that it is possible to reach the end state from any intermediate state as well as the start state. It depends on the system being modeled. Also, the output of each state may depend on the current state as well the inputs to that state. Thus state machines model reactive systems i.e. systems which react. A good description of state machines can be found here. Note that the description there is related to finite state machines, which are so called because they have finite number of states. State machines are used in different fields of study not just electrical or computer engineering. They are used in biology, mathematics, linguistics etc. They also have different variants each trying to capture some additional parameters of a system which I would not go into. You can read about them at the link mentioned earlier.
I was wondering if the world can be modeled as a state machine. I think that the world in fact is a state machine except that its end state is unknown. Those with absolute faith in cosmological physics would state that the “Big Bang” can be considered as the start state. Those with religious views might consider something else as the start state. The beauty of this world being considered as a state machine lies in the fact that it does not matter whether you believe in science or not. It does not matter whether you have more of a religious bent of mind and would like to see the world from a religious or theological perspective or whether you want to see it only from a scientific standpoint. Either way, the world can be modeled as a state machine. You get to choose the start state depending on which viewpoint you are more comfortable with. In both the cases, the world is in fact a reactive system. It can even be considered as an aggregation of interacting state machines where each state machine can represent the economic, social, political, religious and scientific state of the world. And nobody would deny that all these concepts influence each other. Every electrical or computer engineering student studies about Moore and Mealy state machines. To them, the world is probably a Mealy state machine though not strictly so: the outputs in any state that this world resides in is dependent not only on the current inputs but also on the current state. If we look around us, it sounds so true, does it not? However, this state machine is extremely complex!