Part 14/23:
Within this framework, there's the astonishing possibility of infinite variations of Earth and ourselves, potentially existing simultaneously—prompting profound questions about identity, free will, and the nature of existence.
The Search for Extraterrestrial Life and the Limits of Observation
Turning to extraterrestrial life, Greene is cautious. He proposes that advanced civilizations, if they exist, might not be interested in us—they might be galactic, not planetary, or simply too distant for us to detect. The vast timescales involved mean that there is only a slim chance that we are being observed by extraterrestrial intelligences now, given our limited radio emissions.