Imagine you're encoding morse in a protocol that has only an instant pulse. you can't do a dash, only dots.

But you can encode a dot as two dots with a short gap between them, and a dash by two dots with a long gap between them.

And you can of course merge adjacent dots: V is ···-, but you don't need eight dots to represent that, you need 5:
dot-short-dot-short-dot-short-dot-long-dot

and an extra-long gap between two dots is a space

if my math is correct, you encode "hello world" in 39 dots