With apologies to China Miéville for pinching the title, but it is a wonderful title... Today I am using Janelle Stone's "Light Bubbles", a marvellous cityscape image taken from behind a window, and one of mine from Chicago last month.
The light is not the same in the city, in the concrete crevasses it is almost all artificial. The sky comes in slices unless you climb higher, build higher than the others, a Catch-22 race. They invented the skyscraper here, and there is no sign of the swamp from two centuries before. No will o'the wisps floating up on bubbles of swamp gas. The sky light fades so fast, it was day, then the next minute it was dusk and then night was upon us. You came home from the city to my bed, weary with climbing.