A proposal for how to initiate communication with aliens, starting from just mathematics, is Hans Freudenthal’s “Lincos: Design of a Language for Cosmic Intercourse, Part 1”. (No part 2 ever appeared.)
A fictional example of receiving a dangerous message from the stars is Piers Anthony’s “Macroscope”.
A proposal for how to initiate communication with aliens, starting from just mathematics, is Hans Freudenthal’s “Lincos: Design of a Language for Cosmic Intercourse, Part 1”. (No part 2 ever appeared.)
A fictional example of receiving a dangerous message from the stars is Piers Anthony’s “Macroscope”.