Physical social actions are conveniently detected, characterized, and provided to a social networking system. This improves the user experience of the social networking system by more thoroughly recording the social actions of users occurring outside a social graph. This has the effect of extending an open social graph, which typically refers to social actions taken outside the social networking system but within a computer network, to physical social actions. By providing characterized physical social actions to the social networking system, the open social graph is extended to include physical social actions.