Explore Chapter 2 of a lecture from Kyoto University's Spring-Autumn series delivered by Professor Takahiro Tanaka from the Graduate School of Science on November 4, 2017. Delve into the world of general relativity theory as it confronts observational evidence in extreme cosmic environments. The lecture, presented at the Centennial Clock Tower Memorial Hall, is part of a comprehensive series examining the universe at its limits. Access additional chapters of this fascinating exploration of theoretical physics and cosmology through Kyoto University's OpenCourseWare platform.