Explore the first lecture in a series on "Positive Geometry in Cosmology" delivered by renowned physicist Nima Arkani-Hamed at the International Centre for Theoretical Sciences. This 1 hour 45 minute lecture is part of the program "Positive Geometry in Scattering Amplitudes and Cosmological Correlators," which aims to bridge the gap between mathematical aspects of scattering amplitudes and cosmology. Discover how recent advances in perturbative on-shell scattering amplitudes—including unitarity methods, recursion relations, worldsheet models, bootstrap methods, and connections to positive geometry—relate to cosmological correlators that capture the fundamental physics of our Universe. This interdisciplinary workshop brings together experts from different fields of theoretical physics to advance these fascinating connections.