Pick any technological object you use frequently: a cell phone, a laptop computer, an MP3 player. What different kinds of knowledge do you need to use the object? To use the object well? (Think about lightbulbs: you need to know where to buy them, how to screw them into a socket, when to replace them, how to turn them on; you also need a minimal understanding of electricity and wiring, of money, of the uses of light, of how stores work, etc.) List all the social systems-like those of power companies, stores, and so forth-to which the use of the technology ties you.