Centrifugal force

Although the Citadel is equipped with mass-effect-generating element-zero cores, most of the gravity on the station is generated by the centrifugal force of rotation.

The abolition of feudal serfdom in 1861 and the demand for wage labor created by industrialization drew large numbers of peasants to the growing cities in search of paid work. It was this centrifugal force of capitalism in Russia that centralized an urban industrial class in the 1880s and 1890s.