Lincos (an abbreviation of the Latin phrase lingua cosmica) was first described in 1960 by Jewish, German-born Dutch mathematician Dr Hans Freudenthal in his book Lincos: Design of a Language for Cosmic Intercourse, Part 1. Freudenthal considered that Lincos could be easily understood by beings not acquainted with any Earthling syntax or language.
For decades, no actual transmissions were made using Lincos; it remained largely a theoretical exercise until Canadian astrophysicists Yvan Dutil and Stéphane Dumas, working at the Canadian Defense Research Establishment, created a noise-resistant coding system for messages aimed at communicating with extraterrestrial civilisations in 1999. The astrophysicists encoded a message, which was a series of pages describing some basic mathematics, physics and astronomy, in Lincos and used the Yevpatoria RT-70 radio telescope in Ukraine to beam it towards close stars. This experiment is known as Cosmic Call and was repeated (using other close stars as targets) in 2003. Some researchers have explored similar issues in communicating with intelligent animals such as cetaceans through pulses of sound. As Lincos messages are complex, they were oriented to reach the most patient, logically-oriented members of the target species