Morse code

Morse code turns each letter, digit and punctuation mark into a series of dots and dashes: A is "·—", E is "·" and S is "···". You can write it down, but above all you can send it: as short and long sounds, as flashes of a torch or as knocks on a table. That is why it fits an escape room so well: the message can hide in a beep, in a blinking light or in a drawing.

A little history

Samuel Morse and Alfred Vail created it around 1838 for the electric telegraph, and in 1844 the first message was sent between Washington and Baltimore. Vail gave the shortest codes to the letters used most in English. The international version we use today was agreed in 1865 and, for more than a century, it was used by ships, aircraft and radio stations all over the world. The famous "··· ——— ···" (SOS) was chosen as the distress call because it is very easy to send and to recognise. Ñ has a code of its own, "——·——".

Try it

Type a message and you will see its code drawn as dots and dashes. There is a space between letters and a slash between words. To decode, type or paste the code: dots, hyphens, underscores and the signs "·" and "—" all work, and extra spaces do not matter. Characters that do not exist in Morse, such as emoji, are left out.

Listen to it

The player plays the tool's result with the usual timing: a dash lasts as long as three dots, there is a three-dot silence between letters and a seven-dot one between words. Slow it down for beginners. The letter that sounds is highlighted and a light marks each signal; if sounds are off in your preferences, the light still shows the rhythm.

The table

In the classroom

• Sound message. Play a short word slowly and ask students to write it down in dots and dashes before decoding it with the table.
• Light signals. With a torch, or by switching the classroom light off and on, send a three-digit number that opens a lock.
• Body Morse. A clap for a dot and a stamp for a dash: teams send each other messages without speaking.
• Written clue. Print a clue's code on strips of paper, or hide it in a drawing made of circles and lines.

Tips

• Start with the simplest letters: E (·), T (—), I (··), M (——), S (···) and O (———).
• Make it clear where each letter ends: without spaces, "··· ———" becomes "···———", which no longer reads the same.
• Give younger students the printed table; give older ones only half of it, or none.