Cybernetics is the study of control, communications and information processing within systems of all kind, biological, mechanical and social. Norbert Wiener(one of the founders of the subject) defined cybernetics as “the scientific study of control and communication in the animal and the machine.”1 The word cybernetics comes from Greek word meaning “governance” or “to steer, navigate or govern”. Cybernetics formed out of – and is closely related to – the areas of systems theory, information theory, computer science, robotics, mechanical and electrical engineering. The primary object of study within cybernetics are control systems that are regulated by negative feedback loops.2
In order for a system to control itself and maintain homeostasis there needs to be some kind of regulatory mechanism; what is also called a control system. This control mechanism has to regulate both the system’s internal and external environment to ensure that the environmental conditions are within the given set of parameters that will enable the internal processes of the system to function at a normal or equilibrium state. Cybernetics again comes from a Greek word which means to steer or guide, and this is what control systems of all kind are designed to do. They are designs to guide the system in the direction of the set of environmental parameters that are best suited for it to maintenance homeostasis.
Control System Components
All of these very diverse systems, from governments to chemical processing plants to ecosystems share a basic underlying set of relations and components that are common to all regulatory systems. There are essentially just three components to any given control mechanism.3 Firstly, there needs to be some form of a sensor for feeding information into the system, a sensor is a component that detects and encodes some stimulus from the system’s environment and transfers it to the controller. Secondly, there needs to be a controller that contains the logic or set of instructions for processing this information, the controller is the brains of the operation. It contains the critical logic that is governing the whole system and is encoded in some set of instructions. Lastly, an actuator that executes some action in order to affect the state of the system or its environment. An actuator is an instrument or set of instruments that act on the instructions produced by the controller. An actuator is designed to physically affect the system that is being regulated in order for it to conform with the instructions produced by the controller.4
Negative Feedback Loops
Feedback loops are a fundamental object of study within cybernetics in that they are accountable for the process of regulation within all control systems. Feedback loops are divided into two qualitatively different types, what are called positive and negative feedback. A negative feedback loop represents a relationship of constraint and balance between two or more variables. When one variable in the system changes in a positive direction the other changes in the opposite negative direction, thus always working to maintain the original overall combined value to the system.5 An example of this might be the feedback loops that regulate the temperature of the human body. Different body organs work to maintain a constant temperature within the body by either conserving or releasing more heat. Through sweating and capillary dilation, they counter-balance the fluctuations in the external environment’s temperature. Another example of negative feedback loop might be between the supply and demand of a product. The more demand there is for a product the more the price may go up which will in turn feedback to reduce the demand.
In the 1970s, new cybernetics emerged in multiple fields, new cybernetics or second-order cybernetics is sometimes described as the cybernetics of cybernetics. It investigates the construction of models of cybernetic systems looking beyond the issues of the “first”, “old” or “original” cybernetics and the emphasis on control, recognizing that the investigator is also part of the system, and of the importance of autonomy, self-consistency, self-referentiality, and self-organizing capabilities of complex systems. A recognition that the investigators of a system can never see how it works by standing outside it because the investigators are always engaged cybernetically with the system being observed; that is, when investigators observe a system, necessarily they affect it and are affected by it.6 Recent endeavors into the true focus of cybernetics, systems of control and emergent behavior, by such related fields as game theory (the analysis of group interaction), systems of feedback in evolution, and metamaterials, have led to a revived interest in this increasingly relevant field.