Explore cutting-edge research on probing new physics at the horizon of black holes using gravitational waves in this 38-minute conference talk by Elisa Maggio from the Albert Einstein Institute. Delve into the impact of gravitational wave detection on various fields of physics, from field theory to stellar evolution and cosmology. Discover the importance of precision modeling for gravitational wave signals in interpreting strong events and searching for new physics. Learn about the challenges facing next-generation gravitational wave experiments and the promising tools emerging from classical and quantum field theory. Examine topics such as black hole horizons, ringdown, higher modes, models of deviation, spectral changes, quasinormal modes, compactness, energy flux, and gravitational wave dephasing. Gain valuable insights into the future of gravitational wave research and its potential to uncover new fundamental physics.