The European knowledge society is at a critical juncture, marked by the paradoxical omnipresence of experts in social media and growing epistemic instability post-Covid-19. This course aims to dissect the 'autumn of the social media era', a phase marked by the decline of naive digital engagement and the rise of contentious interactions in technoscientific and policy realms. In the first part, we will delve into the sociological dimensions of the 'social bubble crisis', examining virality, influencer culture, and the erosion of reasoned confrontation in favor of fallacies and intolerance. We will explore how these trends impact laypeople and institutional knowledge bearers, fueling distrust and skepticism. The second part will focus on 'epistemic instability', essential for understanding the current state of knowledge, expertise, and political decision-making. We will investigate the challenges faced by scientific communities amid alternative facts, fake news, and the contestation of science and civic pillars in mature democracies. This segment will analyze how public decision-making processes are informed by technoscientific expertise amidst broader epistemological and social dynamics. Throughout the course, we will review alternative routes to navigate this historical transition, encouraging deep reflection on collective shaping of these changes and mitigating undesirable impacts. This prepares us for the potential 'winter' of societal and epistemic challenges. By combining rigorous analysis with a prospective vision, this course opens a new chapter in studying the cultural and communicative dynamics linking science, technology, media, politics, and society. I aim to equip students with a comprehensive understanding of the complexities of the current sociotechnical landscape, emphasizing the need for a symmetrical methodological approach to understanding scientific and non-scientific knowledge forms in contemporary Europe.