Stronger than granite

The city was close now, and I stared at it, trying to understand how it had avoided being buried by the sands of time, or melted when the outer edges of the sun had kissed the Earth as it had turned into a red giant. There shouldn’t have been people here for billions of years. Maybe they’d come from another universe? But the place looked ancient, and conditions would have been even worse the farther back you went. How bad would the universe they’d come from have been to be forced to settle here?

I’d heard once that the granite on Mount Rushmore was eroding at a rate of an inch every ten thousand years. That meant that within less than two and a half million years the faces would be gone, assuming ice falls from glaciers didn’t wipe them away first. At a similar rate, walls that were twenty feet thick of granite would have vanished completely in the same time period. Enhanced vision showed me erosion and pitting on the outside of the walls, but nothing like I would have expected. Either the city was less than a hundred thousand years old, or the material it was made of was a lot tougher than granite.

***

Walker