signals and signaling

The movement of different kinds of vehicles is controlled by traffic lights.

An introduction to the language of railroading, in which words, colored lights, flags, semaphore arms, coded whistles, hand signals, flares, and explosive alarms are used to guide trains and announce their arrivals and departures.

Explains how the soldiers of the world's Special Forces units avoid getting lost in the wilderness by using nature to help them navigate.

Discusses how ways to communicate have changed throughout history from cave paintings to rock pictures to clay tablets to paper. Includes information on how ancient communication forms helped to create modern communication technology.

In eighteenth-century Korea, after Sang-hee's father injures his ankle, Sang-hee attempts to take over the task of lighting the evening fire which signals to the palace that all is well. Includes historical notes.

All day and night the traffic signal blinks its messages of stop and go.