The Last Evolution
I feel a wistfulness about its closing paragraphs, similar to that in two other Campbell stories, Twilight and Night. These also feature wonderful computers. Night tells of an anti-gravity test flight which goes awry, flinging its test pilot into a future long after mankind has died out. But Man's machines survive, and the pilot visits them in their neon-lit city on Neptune. Neon-lit; and amongst the cold light, are there drifts of neon on the ground? The story's wistful mood arises partly because despite their great intelligence, these machines lack (if I remember correctly) one essential attribute — I shan't reveal what in case I spoil the story.
Night doesn't seem to exist online, but I did find a review on Jason Ellis's Dynamic Subspace site. As for Twilight, there's supposedly a copy at http://www.naderlibrary.com/eiseley.twilight.johnstuartcampbell.htm, but the server is down today: try Google's cache. I first read both stories in Tandem's collection The Thing from Outer Space, and suspected then that they came from the same future history. In Twilight, Man still lives. So do his machines. But so far into the future is it, that more time has elapsed since their creation than between me and a flint axe. The stars have moved; dogs have evolved, become intelligent, died out. And in the same way that science-spurning teenagers prod their pink iPods and their Facebook phones:
all those people knew was that to do a certain thing to a certain lever produced certain results. Just as men in the Middle Ages knew that to take a certain material, wood, and place it in contact with other pieces of wood heated red, would cause the wood to disappear, and become heat. They did not understand that wood was being oxidized with the release of the heat of formation of carbon dioxide and water. So those people did not understand the things that fed and clothed and carried them.
Twilight was declared by the Science Fiction Writers of America to be one of the best science fiction short stories of all time.