Lincos

Lincos (an abbreviation of the latin phrase "lingua cosmica") is an artificial language first described in 1960 by Dr. Hans Freudenthal[?] and described in his book LINCOS: Design of a Language for Cosmic Intercourse. It is a language designed to be understandable by any possible intelligent alien life form, for use in interstellar radio transmissions.

The Lincos "dictionary," intended to be transmitted first before any additional messages, begins with an extremely simple pattern of pulses intended to establish the terminology for natural numbers and basic arithmetic (addition, subtraction, multiplication and division) in base two. The concepts of equality, comparison, variables and constants are also illustrated by a series of examples, and then finally propositional calculus, set theory and predicate calculus. The next section of the Lincos dictionary establishes vocabulary for describing time, introducing means for measuring durations, referring to moments in time, and talking about past and future events. The 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. Finally, the fourth section describes the concepts and language relating to mass, space, and motion. This last section goes so far as to describe physical features of human beings and of the Solar system.

A second book was planned but never written that would have added four more sections to the dictionary: "Matter," "Earth," "Life" and "Behavior 2." Other researchers have since extended the language somewhat on their own.

No actual transmissions have been made using Lincos; it remains largely a theoretical exercise.

An example of Lincos from section 3 of Freudenthal's book, showing one individual asking another individual questions:

Lincos text	Meaning
Ha Inq Hb ?x 2x=5	Ha says to Hb: What is the x such that 2x=5?
Hb Inq Ha 5/2	Hb says to Ha: 5/2.
Ha Inq Hb Ben	Ha says to Hb: Good.
Ha Inq Hb ?x 4x=10	Ha says to Hb: What is the x such that 4x=10?
Hb Inq Ha 10/4	Hb says to Ha: 10/4.
Ha Inq Hb Mal	Ha says to Hb: Bad.
Hb Inq Ha 1/4	Hb says to Ha: 1/4.
Ha Inq Hb Mal	Ha says to Hb: Bad.
Hb Inq Ha 5/2	Hb says to Ha: 5/2.
Ha Inq Hb Ben	Ha says to Hb: Good.

Note the difference between "good" and "bad" and "true" and "false"; 10/4 is a true answer to the question, but it isn't what Ha wanted because Hb didn't reduce the fraction to its lowest terms.

Another example, showing meta-conversation:

Lincos text	Meaning
Ha Inq Hb ?x 4x=10	Ha says to Hb: What is the x such that 4x=10?
Hb Inq Hc ?y y Inq Hb ?x 4x=10	Hb says to Hc: Who asked me for the x such that 4x=10?
Hc Inq Hb Ha	Hc says to Hb: Ha.

External link: http://www.socialfiction.org/lincos.htm