TITLE: What is necessary to exchange messages between aliens?
QUESTION [13 upvotes]: Lets assume that two extreme intelligent species in the universe can exchange morse code messages for the first time. A can send messages to B and B to A, both have unlimited time, but they can not meet.
Is it possible to transfer information between both species? What would be the mathematical precondition for information exchange?
If A sends "Hello friend" to B, he might not understand this message, but could A train B to understand the code of A?
For example A could expect, that B will know logic and first send some definitions like the generation of natural numbers and primitive logic or calculations.
Has there been a publication in a journal on this topic?

REPLY [2 votes]: there is also a biological/anthropological answer. You didn't mention that the aliens were an advanced civilization, but only that they had enough technology to communicate with us.
The, there is this tribe in the Amazonia (in Brazil), called the piraja. they do not understand numbers larger than 4 or 5. the rest means "many". I suspect this is not cultural, but some kind of inbreed mutations that results in acalculia. Many people on our society suffer from acalculia, which involves average or even above average intelligence but total incapacity to grasp the meanaing of the natural numbers. Thus, if the aliens were acalculic but otherwise intelligent, they would find it difficult to decipher a code based on math! just my two cents on a fringe issue that could bear some weight in the answer