When describing a world to your players, what are the descriptive keywords you typically use to get across a sense of the world's technology level? To be clear, I'm talking specifically about atmospheric description as they walk through a city.
I'm more interested in ideas for the higher technology levels. It's pretty easy for me to drop in something about a steam locomotive or power lines or the cooling towers of a fission planet. But what are the "key indicators" that make a TL-9 society feel different from a TL-10 from a TL-11 from a TL-12? At what level should WALL-E style robots be described as cleaning up a mess on the street? When does a floating advertisement for a hair replacement clinic show up hawking neon-green follicles for CHEAP?
I'm more interested in ideas for the higher technology levels. It's pretty easy for me to drop in something about a steam locomotive or power lines or the cooling towers of a fission planet. But what are the "key indicators" that make a TL-9 society feel different from a TL-10 from a TL-11 from a TL-12? At what level should WALL-E style robots be described as cleaning up a mess on the street? When does a floating advertisement for a hair replacement clinic show up hawking neon-green follicles for CHEAP?