Olaf Dreyer talks about "internal relativity," a new approach to quantum gravity. The speaker discusses two views of special relativity: Lorentz's idea that matter defines geometry, and Einstein's view where matter conforms to a background geometry.

Explore more:

• "Martin Bojowald - Hypersurface deformation structures and space-time models": Deformations of spacelike hypersurfaces in space-time have recently been shown to form an L-infinity algebroid. Space-time models for gravitational field theories, however, are commonly derived and analyzed using a Poisson bracket. The discrepancy may have implications for physics questions such as the nature of black-hole singularities.
• Martin Bojowald (Penn State), The cycles of bouncing cosmology:This video is part of the PROTEUS project that has received funding from the European Research Council (ERC) under the Horizon 2020 research and innovation programme (Grant agreement No. 758145) Key.
• Dirty Secrets of Cosmology by Anthony Aguirre: More dirty secrets, this time with cosmology. Join Anthony Aguirre as he delves into profound questions about the nature of the universe, eternal inflation, cosmological parameters, gravitational waves, and more.