Why it is built this way
The letters come simplest first, not alphabetically. E is one dot because E is the commonest letter in English, and Morse counted the letters in a printer's type case to decide. The commonest letters got the shortest codes, which is the same idea as a resistor band. Save the sender's time.
A dash lasts three times as long as a dot. The gap inside a letter is one dot, between letters three, between words seven. Get the rhythm right and it works by sound, by light, by tapping on a pipe, or by squeezing somebody's hand.
A code that became a voice
Tania Finlayson, who has cerebral palsy, communicates through morse: a device reads her head movements, turns them into short and long signals, and speaks the result aloud. She then worked with Google to put a morse keyboard into phones, so anyone who can make two signals can write.
Two sounds is the smallest code that can carry a language. That is why it survives.
Now use it
A torch at a window, a spoon on a radiator, a finger on somebody's arm. Send a word, and see if they can send one back.
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