Object Lessons is a series of short, beautifully designed books about the hidden lives of ordinary things. Alarms are alarming. They wake us up, demand our attention and force us to attend to things we've preferred to ignore. But alarms also allow us to feel secure, to sleep and to retreat from alertness. They take over vigilance on our behalf. From the alarm clock and the air-raid siren to the doorbell and the phone alert, the history of alarms is also the history of work, security, technology and emotion. Alarm responds to culture's most urgent calls to attention by examining all kinds of alarms, from the restless presence of the alarm clock in modernist art to the siren - the sound of the police - in classic hip hop. More than just bells and whistles, alarms are objects that have defined sleeping and waking, safety and danger, and they have fundamentally shaped our understanding of the mind and its capacity for attention. Object Lessons is published in partnership with an essay series in The Atlantic.