Week 08 · Secret Codes

Tuesday

Cracking Morse code

// Patterns that carry information

⏱ about 15 min

Tuesday: Cracking Morse code

The next morning, Raven runs to Rocket's porch with her notebook. "I wrote down your blinks," she says.

Rocket grins. "Did you crack it?"

"Almost," Raven says. "Three short, three long, three short. What do you notice about the three groups?"

Nova opens a glowing chart in the air. "Would you like a hint? Match each group of three to a letter on this chart."

Here are some letters from International Morse code. A dot is written as a period. A dash is written as a short line.

A  . -        N  - .
E  .          O  - - -
H  . . . .    R  . - .
I  . .        S  . . .
T  -

A dash lasts as long as three dots.

Leave a short gap between letters, and a longer gap between words.

Three dots, three dashes, three dots spells S O S. It is an international signal that a ship needs help.

Decode Rocket's blinks: . . . - - - . . .

Decode this word: . . . . . -

Decode this word: - . . -

ENCODE A LETTER

Which pattern is the letter T?

Which letter has four dots?

Try it

Tap your name in Morse code on a table.
You may need to look up letters that are not on today's chart.

Without gaps, Morse code would be one long jumble of beeps.

A short gap tells you one letter has ended.

A longer gap tells you a whole word has ended.

MORE DECODING

Decode: . .

Decode: - - -

How long does a dash last?

Decode this word: . . . . . - -

Decode this word: - . - - -

Decode this word: . . . . . .

ENCODE THE WORD RAT

WHY THIS EXERCISER is dot dash dot, A is dot dash and T is one dash.

Statement	True or false?
S O S is a signal that a ship needs help.	?
E is a single dot.	?
N and A use the same pattern.	?

WHY THIS EXERCISEN is dash dot. A is dot dash. Order matters.

Write a three letter word using only letters from today's chart. Then write it in dots and dashes.

You cracked a real code today! Tomorrow you test which way of sending a message works best.

Grown-up checked my answers