George A. Miller
There is an old and not very funny story about stepping on a dog's tail. If the dog barks, you can call it an accident, but if you step on his tail in New York and he barks in London, you have to call it communication.
Certainly there are many different kinds of communication and, for all I know, stepping on a dog's tail may be one of them, although I hope not. The point of the story, if it has any point at all, is that "communication" is a very abstract word. It can be accomplished by an endless variety of means. If we try to say in the most general terms what all the different kinds of communication have in common, it comes down to something like this: Communication occurs when events in one place or at one time are closely related to events in another place or at another time. For example, the vocal sounds made when one speaks into a radio microphone are closely related to the vocal sounds produced wherever and whenever an audience happens to hear them. Any physical process that has this capacity to span space and time can be used as a communication system. Human speech, which provides a way for events in the nervous system of the speaker to affect events in the nervous system of another, is one kind of communication, but it is only one of many different ways the abstract concept of communication can be realized in a practical form.
It is in this very abstract sense that we can talk about communication between machines, or the communication of diseases, or the hereditary communication of traits from parents to their