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Communication with extraterrestrial intelligence - Wikipedia
CETI, a branch of SETI, pursues constructing and deciphering interstellar messages intelligible to another technological civilization, spanning mathematical and logical languages (Lincos, Astraglossa), pictorial systems (Arecibo, Pioneer plaques, Voyager records), algorithmic communications (ACETI, CosmicOS, Logic Gate Matrices), and computational approaches to unknown or natural-language-like signals, with pictorials relying on shared perceptual concepts; notable efforts include Frank Drake’s 1974 Arecibo message, the Pioneer plaques conceived by Burgess and Sagan, the Voyager golden records, and Cosmic Call adding multi-modal content; algorithmic messages embed executable programs or virtual machines (CosmicOS and Lone Signal’s binary language); multi-modal messages combine text, images, video, and audio (Teen-Age Message, Cosmic Call 2); natural-language research seeks language-like structure without assuming human language, using statistical token patterns and universal principles to distinguish language from noise; the CETI community includes Frank Drake, John Elliott, Laurence Doyle, Stephane Dumas, Yvan Dutil, Paul Fitzpatrick, Brian McConnell, Marvin Minsky, Carl Sagan, Douglas Vakoch, Alexander Zaitsev, Seth Shostak, and David Brin, who debated active messaging in 2015 prompting calls for worldwide discussion; interspecies communication work considers teaching tasks to Earth’s intelligent animals as stepping stones toward recognizing non-human intelligences beyond Earth; the field remains deeply interdisciplinary, balancing hopeful strategies with caution about misinterpretation, noise, and the societal implications of contacting extraterrestrial life.
