When you drop a hammer, its freefall follows a geodesic, which could be considered a "straight line" through spacetime... at least until the ground gets in the

When you drop a hammer, its freefall follows a geodesic, which could be considered a "straight line" through spacetime... at least until the ground gets in the way. In some sense, you could say that the ground is accelerating upward at a constant 9.8 m/s². When we feel weight, that's just regular inertia, pushing back against the ground's acceleration. (I'm not sure to what extent this follows the mainstream interpretation of Einstein's equivalence principle. It at least requires a different definition of "acceleration", given that the Earth's radius is not increasing.)