The light bulb changed world geography because it allowed predominately agrarian societies to become increasingly industrial. Prior to the development of the light bulb, life revolved around the rising and setting of the sun for the completion of work. Farmers rose with the sun to begin their work, and their workday ended when the sun set. Society used the limited power of candles and oil lamps for evening tasks. With the advent of reliable light sources, retail and industrial society could operate long after the sun set. Once reliable power grids were established, cities grew and operated around the clock thus changing the landscape and work environment. Rural communities often took longer to change because the power sources for electrical lighting were not established as quickly. People looking to capitalize economically, moved closer to urban areas which became more and more congested but provided for growth of new industries and retail establishments. Factories were able to extend work hours, which impacted society both positively and negatively. Community housing was established for those who worked in the non-stop mills and other industrial establishments. The world no longer depended on the rising and setting of the sun to determine when daily work would occur.