Our world is so complex that we take for granted engineering processes that would dwarf any of the ancient Seven Wonders of the World; 

we ride railroad tracks that do not follow faithfully the curvature of the earth, for the train would jump the tracks if they were level. 

We pass skyscrapers whose stress and strain are figured to the millionth of an inch, yet take for granted that the Empire State Building actually sways constantly many feet.