In this episode, we chat again with John Doyle about the frontiers of control theory. Starting from the fascinating interplay between bacteria, physics, and the Internet, we explore the universal laws that govern complex systems. We discuss the inner workings of phenomena like earthquakes, wildfires, and sepsis, emphasizing the vital role of control theory in understanding intrinsic tradeoffs and fragilities. Finally, we discuss the essential components of a full theory of architectures,  including universal laws, layers, levels, and diversity-enabled sweet spots. Outline 00:00 - Intro 03:00 - Complex systems, physics, and the Internet 08:31 - On power laws 13:45 - SBML: Systems Biology Markup Language 18:51 - Layered architectures 21:38 - Earthquakes 26:17 - Wildfires 28:25 - Sepsis 37:18 - Essentials of a theory of architectures 54:10 - Universal laws, layers and levels 1:00:30 - Diversity enabled sweet spots  1:12:49 - Witsenhausen’s counterexample and SLS 1:21:25 - On the internal model principle 1:29:38 - Evolution vs intelligent design 1:33:37 - Fragility and societal implications 1:44:31 - Outro Links Highly optimized tolerances and power laws paper: https://tinyurl.com/3yk2mycp Robust perfect adaptation in bacterial chemotaxis paper: https://tinyurl.com/3fn62a73 SBML: https://sbml.org/ Internet congestion control paper: https://tinyurl.com/4rjcd724 The Structure of Scientific Revolutions: https://tinyurl.com/44n9y23u Wildfires paper: https://tinyurl.com/2dvdh8ap Turbulence paper: https://tinyurl.com/3sbsf8nj Sepsis paper: https://tinyurl.com/55wse56f Distributed LQG with delays paper: https://tinyurl.com/2abjdmb4 Diversity-enabled sweet spots in layered architectures paper: https://tinyurl.com/vvaxvwb8 Mountain biking game: https://tinyurl.com/46yh559r System-level synthesis paper: https://tinyurl.com/2ez64jev Internal feedback in biological control paper:  https://tinyurl.com/576zdfrx Support the showPodcast info Podcast website: https://www.incontrolpodcast.com/ Apple Podcasts: https://tinyurl.com/5n84j85j Spotify: https://tinyurl.com/4rwztj3c RSS: https://tinyurl.com/yc2fcv4y Youtube: https://tinyurl.com/bdbvhsj6 Facebook: https://tinyurl.com/3z24yr43 Twitter: https://twitter.com/IncontrolP Instagram: https://tinyurl.com/35cu4kr4 Acknowledgments and sponsors This episode was supported by the National Centre of Competence in Research on «Dependable, ubiquitous automation» and the IFAC Activity fund. The podcast benefits from the help of an incredibly talented and passionate team. Special thanks to L. Seward, E. Cahard, F. Banis, F. Dörfler, J. Lygeros, ETH studio and mirrorlake . Music was composed by A New Element.