Alien civilizations have not visited Earth and never will, physicist claims
“There is a silence in the night sky that has bothered me for as long as I can remember.” That line, attributed to Richard Feynman, lands because it gets at a simple, stubborn feeling. The sky looks full. Stars crowd the darkness. It seems reasonable to think someone else should be out there, and close enough to find. Yet the deeper physicists look into the laws that govern the universe, the more that silence starts to seem less like a cosmic riddle and more like a built-in feature of reality. Human intuition is not much help. It developed for ordinary distances, daily motion, and short-term survival. It did not develop for light years, relativistic speeds, or timescales longer than the history of civilization. As Feynman puts it, “When you take that human intuition and apply it to the scale of the universe, it doesn’t just fail. It snaps.” That mismatch sits at the center of the story. Five barriers shape the quiet: distance, the speed of light, propulsion, biology, and time. Taken together, they form …
