EssayBoard

What if our observable universe isn’t just big—but fundamentally isolating?

The idea of a “black domain” was popularized by Chinese science fiction author Liu Cixin in Death’s End, where civilizations create artificial regions of space where the speed of light is reduced to trap themselves from the outside universe—a desperate strategy for survival in a hostile cosmos. Within such a domain, nothing can escape, and no one can intrude. A cloaked tomb of silence.

But here’s the real twist: even if our universe isn’t a black domain in the science-fiction sense, it might as well be one in practice.

We live under the unbreakable ceiling of the speed of light. Our furthest signals take years, centuries, or even millennia to reach distant stars. And as space expands—fueled by dark energy—entire galaxies are pulled away from us faster than light itself can bridge. Many galaxies are now beyond our cosmic event horizon. Even if intelligent life exists there, we will never know. Ever.

This makes the observable universe a de facto black domain. Not by artificial design, but by the cruel laws of nature. We are trapped by causality, light-speed limitations, and the expansion of spacetime.

The Fermi Paradox—”Where is everybody?”—may have a simple answer: they’re out there, but unreachable. Perhaps civilizations evolve, wonder, and die in cosmic solitude, each isolated in their own sector of space, unable to reach another before the silence of entropy sets in.

Now imagine the eerie possibility: there may be many civilizations trapped in this same cosmic bubble with us. But the universe is so vast, so expanding, that none of us will ever cross paths. Like prisoners in separate cells, we scream into the void, unaware others may be doing the same.

Whether through fiction like Liu Cixin’s black domain or the inescapable math of cosmology, the truth is the same: our universe behaves like a prison.

But even in that prison, we look up.

And sometimes, the longing to connect is what keeps us most human.