General Relativity
Replace gravity as an ordinary force with geometry. Matter and energy shape spacetime, while freely falling objects follow the geodesics available in that curved geometry.
Acceleration points toward geometry.
The equivalence principle suggests that local gravitational effects can be transformed away in free fall. General relativity turns that clue into a geometric theory: curvature remains when no single global inertial frame can remove gravity everywhere.
Light follows spacetime too.
Gravitational lensing is not light being electrically or mechanically pulled sideways. Light follows null geodesics of the curved spacetime geometry.
Move from equivalence to strong-field spacetime.
Connect locally uniform gravity and accelerated motion as the conceptual doorway to geometric gravity.
Interpret free fall as inertial motion along geodesics of curved spacetime.
Understand why clocks at different gravitational potentials accumulate different proper times.
Explore event horizons, photon paths, gravitational lensing, and strong-field spacetime geometry.