< Free Knowledge Culture Calendar 
Today in 1974 humanity made its first attempt at intergalactic communication by sending the Arecibo message. We have not yet received an answer from E.T., which will not be possible for about 60,000 years due to the stagnating progress in physics.
This article is issued from Wikibooks. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.