The Quiet Cosmos: Eight Explanations for Fermi's Paradox

To the point

Despite the universe’s vast age and size, we haven’t found or heard from any aliens, and eight plausible explanations—from our late arrival and flaws to cosmic dangers and the limits of travel and curiosity—could explain the cosmic silence.

Where Are the Extraterrestrials?
psychologytoday.com

Where Are the Extraterrestrials?

How can we best explain our current physical and psychological isolation in the cosmos?