Catalog · The Early Universe Lecture 12 of 23 Lecture 12: Non-Euclidean Spaces: Open Universes and the Spacetime Metric ← Previous Lecture 11: Non-Euclidean Spaces: Closed Universes Next → Lecture 13: Non-Euclidean Spaces: Spacetime Metric and Geodesic Equation ✓ Mark complete Materials Transcript (PDF) ↗ transcript