Different under the surface

An interesting quote from "Halting State" (Charles Stross):

"We used to have sliderules and log tables, then calculators made them obsolete. Even though old folks can still do division and multiplication in their heads, we don't use that. We used to have maps, on paper. But these are all small things (...) The city look the same, but underneath its stony hide, nothing is quite the way it used to be. Somewhere along the lines we ripped its nervous systems and muscles out and replaced them with a different architecture. In a few years it'll run on quantum key exchange magic, and everything will have changed again. But our time-traveller - they won't know that. It looks like the 20th century"

Why do I blog this? I found intriguing this familiar-but-different depiction. The scene happens when 2 characters of the novel wander around Edinburgh in 2018 and discuss how it would look familiar to a time-traveller coming from the 50s and how it's only underneath the surface of buildings and infrastructures (as well as clothing style and presence of cell-phones) that things work very differently.

This is quite interesting as it seems to follow how innovation works (step by step most of the time) with disruptions under the surface of things.