The question of gentrification The question of gentrification is made complex by the fact that the urban qualities it produces—lively street life, profuse commerce, preservation and upgrading of old buildings—are highly desirable, the substrate of urbanity. The problem with gentrification is with its particulars and with its effects. Gentrification suppresses reciprocity by its narrowed scripting of formal and social behavior, by turning neighborhoods into Disneylands or Colonial Williamsburgs, where residents become cast members and the rituals of everyday life become spectacle or food for consumption. Michael Sorkin, 20 Minutes in Manhattan gentrificationurbanism
Ideas behind their time An Article by Tim Harford www.ft.com These days I am more interested in the reverse case [of Da Vinci's helicopter]: ideas that could have worked many centuries before they actually appeared. The economist Alex Tabarrok calls these “ideas behind their time” Curious minds want to know why these ideas appeared so late — and whether there might be anything that would prevent delays in future. One explanation is that the ideas aren’t as simple as they appear. The bicycle is not as straightforward an invention as it seems. To move from ox-hauled cart to human-powered bicycle requires smooth-rolling wheel bearings, which in turn need precisely engineered bearing balls. Modern steel ball bearings were not patented until the late 1700s, and demand from the 19th-century bicycle industry helped to improve their design. Materials and how to employ them inventionideas