Algorithmic Communication with Extraterrestrial Intelligence (ACETI)
Many different strategies for communication with extraterrestrial intelligence (CETI) have been proposed since the invention of wireless communication. These strategies can be roughly divided into two categories: pictorial and mathematic systems.
Pictorial messages, such as the bitmap transmitted from the Arecibo radiotelescope in 1975, can be used to communicate a wide variety of ideas and symbols. Non-pictorial systems, such as Hans Freudenthal’s Lingua Cosmica, allow the sender to build a symbolic vocabulary without the use of digitized images.
It is also possible to construct a complex message by using algorithms as a foundation upon which a rich symbolic vocabulary can be built. This strategy is superior for several reasons: 1) a practical general-purpose programming language can be built using a lexicon of a few dozen fundamental symbols, initially requiring the recipient to decipher only a small library of easily understood symbols, 2) algorithms can be used to depict, or simulate, complex scenarios (e.g. to depict an increase of the entropy within a closed system), 3) the sender can transmit complex programs without requiring the recipient to understand every intermediate software component used within a program, 4) the message can include algorithms that automatically check for, and correct transmission errors.