We live inside systems that correct us before we notice them. A thermostat steadies a room. A clock disciplines a city. A power grid balances every second. An aircraft survives by computation. A medical device listens to the body. A feed learns what holds the eye and quietly reshapes attention. Control - The Hidden Technology is a sweeping, story-driven journey through the feedback loops that made the modern world possible. Moving from ancient water clocks and lighthouse flames to steam governors, electrical grids, rockets, self-driving cars, smart buildings, medical automation, robots, and artificial intelligence, Anders Hansson reveals a hidden history of machines that sense, compare, decide, and act. This is not only a book about technology. It is a book about trust, judgment, power, comfort, safety, and responsibility. Why do stable systems fail? When should automation take over, and when must a human remain in command? What happens when the controlled variable is not speed or