The chances of contacting extraterrestrial civilizations seem slim – Science News February 24, 1973
The possibility of life… on other planets stimulated the imagination of many people… U Nature on February 9, James KG Walker of Yale University examines the possible parameters of such a search and comes to some pessimistic conclusions.
Renewal
Walker estimated that it could take anywhere from 1,400 to 14 million years to make contact with aliens with available technology. This is much longer than researchers have spent listening to extraterrestrial radio signals and studying the sky with telescopes and satellites.
Despite the silence, scientists sent their own messages into the void. In 1974, Earth sent a string of binary code from the Arecibo Observatory in Puerto Rico. Many years later, perhaps the most famous message—the Gold Record—went into space aboard a NASA spacecraft.
If aliens ever make contact, they could send quantum messages, scientists say. Regardless, the aliens are probably so far from Earth that their civilization will have collapsed by the time we get word.