Named after Samuel Morse (1791-1872)—Morse code is a simple code in which letters are represented by dits and dahs. The code, which is a milestone in long- range communication, was designed so that telegraph operators could communicate via a series of electrical signals. In 1844, several years after Morse and his partner Alfred Vail had created the code. Morse demonstrated to the American Congress the power of the telegraph by using the code. To their awe, he sent the message "What hath God wrought" from Washington to Baltimore at a speed that no horse or car could hope to match.
Congress was skeptical of Morse for several years before they agreed to build the Washington-Baltimore line (at the enormous cost of $30,000). Morse code took off and was soon used internationally by militaries, railroads, and businesses. The first form of radio communication was "wireless telegraphy," which involved transmitting Morse code via radio.
Morse code assigns a single unit of time to a dit and three units of time to a dah. Between each letter are pauses of three time units and pauses of seven time units between words. The precise unit of time varies with the operator, as skilled Morse-code operators could regularly transmit and receive twenty to thirty words per minute.
Morse code has now been largely superseded but it is still used occasionally, especially among ships. The famous SOS signal (three dits, pause, three dahs, pause, three dits) is used as a distress signal. Amateur radio enthusiasts from all over the world communicate with the reliable dits and dahs of Morse code.
