How can short and long signals carry words?

A light flashes briefly, pauses, and shines for longer. No voice has spoken and no letter has appeared on a screen, yet someone who knows the pattern can read a message. International Morse code carries written characters through short and long signals, using their order and the spaces between them.

A short signal, called a dot, sets the basic unit of time. A dash lasts three of those units. A can be sent as dot–dash, while N is dash–dot. Each includes a one-unit pause between its two signals. From its first signal’s beginning to its last signal’s end, either letter takes five units: one plus one plus three for A, or three plus one plus one for N. Equal total time does not mean equal meaning.

The quiet spaces organize the message. A one-unit gap joins the parts of one letter. A three-unit gap separates neighboring letters. A seven-unit gap separates words. These are the whole lengths of the gaps, not extra time added after another pause. Without the right separation, a listener or viewer could group the signals incorrectly.

Sending A followed by N as two letters illustrates the structure. The five-unit A is followed by three silent units and then the five-unit N. The whole pair takes thirteen units, with no extra pause counted before or after it. The signals carry the letter patterns; the middle silence marks where one letter finishes and the next begins.

A slower sender can stretch the unit while keeping these proportions. Tones or flashes can carry the same pattern because the information depends on timing rather than a particular voice. Sender and receiver still need a shared code and a clear signal. Even a simple on-and-off channel can carry words when time is carefully organized.