Messages can be encoded in ice by precisely controlling the freezing rate to manipulate the size, shape, and distribution of air bubbles, enabling storage of binary or Morse code.

Now, scientists have come up with a way of encoding messages in the colours of glowing bacteria. ... digit or symbol. For example, two yellow spots signify a 't', ...

Now, scientists have come up with a way of encoding messages in the colours of glowing bacteria. ... digit or symbol. For example, two yellow spots signify a ‘t’, ...

A METI protocol considers several factors including signal encoding, message length, information content, anthropocentrism, transmission method, and transmission periodicity.