Explore the fascinating world of gravitational waves and black hole collisions in this 31-minute video featuring expert answers to Physics Girl's questions. Delve into complex topics such as the speed of gravity, the nature of spacetime, and the detection of gravitational waves. Learn about the LIGO (Laser Interferometer Gravitational-Wave Observatory) and its role in observing these cosmic phenomena. Discover how scientists measure the stretchiness of space and the innovative techniques used to detect minute distortions in spacetime. Gain insights into the latest research and findings in the field of gravitational wave astronomy, including the groundbreaking observations of black hole mergers. Perfect for physics enthusiasts and curious minds alike, this video offers an engaging and informative journey through some of the most intriguing concepts in modern astrophysics.