It is a language designed to be understandable by any possible intelligent extraterrestrial life form, for use in interstellar radio transmissions.
[citation needed] Freudenthal's third section is perhaps the most complex, and attempts to convey the concepts and language necessary to describe behavior and conversation between individuals.
It uses examples to introduce actors speaking to each other, asking questions, disapproving, quoting other people, knowing and wanting things, promising, and playing.
[citation needed] Finally, the fourth section describes the concepts and language relating to mass, space, and motion.
[1] A second book by Freudenthal, planned but never written, would have added four more sections to the dictionary: "Matter", "Earth", "Life", and "Behavior 2".
Another is a second-generation Lingua Cosmica[4] developed by the Dutch-Swedish astronomer and mathematician Alexander Ollongren[5] of Leiden University, using constructive logic.
[1] Freudenthal's book on Lincos discusses it with many technical words from linguistic and logical theory, usually without defining them, which may have reduced its general interest, though the main chapters can be understood without these technical terms: appellatives, binding, formalization, function, lexicology, logistical, ostensive, quasi-general, semantics, syntax, variables, etc.
[citation needed] 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 civilizations.
[citation needed] In 1999, the astrophysicists encoded a message in Lincos and used the Yevpatoria RT-70 radio telescope in Ukraine to beam it towards close stars.