The Comfort of Stone
Before we could build, we lived where the planet had already made homes for us. Our first palaces and great halls were caves, nestled among boulders, laid in the roots of mountains. Even in our nomadic phases we stuck close to natural defensible spots when we set up camp, using river banks and cliffs and hills and outcroppings as temporary redoubts.
When we began to settle in earnest, we created the city. We quarried and dragged our caves out of the earth, pulling them over our heads like a blanket. There's a particular feeling you get being around or inside a stone building. I think it's their cousinhood to terrain features. A megalithic structure that's been around for five, ten, fifteen thousand years has practically become part of the planet, resettling into its former identity as a cliffside or the spine of a hill.
As science fiction writers have chronicled the colonization of space, something we see a lot is people making their homes in asteroids and little airless moons. In spite of the growing number of goldilocks worlds we're spotting in other systems, this is probably going to be the dominant case. Most of the rock out there we could feasibly anchor a settlement to probably doesn't look like the endless temperate forests and semi-arid glacial debris plains of planet of the week TV shows. The galaxy's not actually a billion xeroxes of fifty square miles of Southern California.
We'll probably be tunneling and honeycombing asteroids and planets with inhospitable surfaces most of the time. Maybe the most in-depth look at this idea is in James S.A. Corey's Expanse series. The asteroid-dwelling Belters, after a couple hundred years, not only have their own distinct culture and verbal patois, they're perhaps the first human variant since Neanderthals were absorbed into Homo Sapiens that could legitimately be called a distinct race. They've evolved to live in microgravity, with elongated skeletons and a highly developed sense of three dimensional orientation. For this they sacrifice the ability to live in significant gravity, lacking the strength and skeletal integrity to withstand the crinkles Earth puts in spacetime.
We came up in caves, and as we grew and flourished, we chipped and shaped and mortared new ones as monuments to the planet that bore us. Long from now, when we leap from the gravity well for good, we may well return to what we know, digging new caves to shelter in from the comforting stone that dots space in precious quantities. After hundreds of thousands of years of Homo Sapien primacy, our future may require us to evolve into a whole new race of cavemen.