How does the changing use of social media affect politics? In her recent book, Political Turbulence, Helen Margetts and colleagues Peter John, Scott Hale and Taha Yasseri show how social media are now inextricably intertwined with the political behavior of ordinary citizens, and exert an unruly influence on the political world. As people go about their daily lives, they are invited to undertake "tiny acts" of political participation (liking, sharing, tweeting, retweeting, following, uploading, viewing, signing, and so on) which extend the ladder of participation at the lower end. These micro-donations of time and effort can scale up to large mobilizations—most fail, but some succeed rapidly and dramatically through a series of chain reactions. When deciding whether to participate, people are exposed to web-based social influence, such as social information about the participation of others. Different types of people have different responses to these forms of social influence. The book uses large-scale data and data science approaches, including experimentation, to explore how such dynamics inject turbulence into the political world, with mobilization characterized by instability, unpredictability, and often unsustainability. In this talk, Professor Margetts will discuss the implications of these findings both for political science research and the future of the modern state.