Most stars have planets, with over 6,000 exoplanets discovered so far, suggesting countless potentially habitable worlds exist in the Universe.
Despite searching for evidence of alien civilizations, none has been found, prompting various theories: life may not exist elsewhere, Earth is in a "cosmic zoo," or civilizations self-destruct upon gaining power.
A new idea suggests that AI could be the reason for the lack of detection, based on a re-examination of
Carl Sagan's musings.
Author's summary: Alien AI may be causing civilizations to become "invisible".