A Brief History of Signals

Prior to the advent of practical electrical communication, human beings had been signaling over a distance in all kinds of ways. The bell in the church tower called people to religious services or “for whom the bell tolls”—the announcement of a death. We knew a priori several things about church bells. We knew approximately when services were to begin, and we knew that a long, slow tolling of the bells announced death. Thus we could distinguish one from the other, namely a call to relig...

 Can Social Networking Change the Human Brain

Consider, for example, the fact that the size of military units has not changed materially in thousands of years, even though our communication technology (from signal fires to telegraphy to radio to radar) has. The basic unit in the Roman army (the “maniple”) was composed of 120-130 men, and the size of the analogous unit in modern armies (the company) is still about the same. The fact that effective human group size has not changed very substantially — even though communication techno...