ScienceClic on Youtube has amazing videos on this topic as does Veritasium. Einstein's happiest thought helps with understanding this. He thought that there would be no discernible difference between what a man felt while falling off a ladder (let's not factor in air resistance) and what a person in 0g space felt.
We are actually "accelerating" upwards at a constant rate that is equal to what we feel and many think of as gravity. This is because spacetime is curved by the mass of the earth.
Think of a grid being distorted or squeezed / pinched. The distortion pinching is "gravity". Everything in the grid still travels in a straight path relative tot he lines on the grid but since the [spacetime] grid is pinched, it looks as if it is not on a straight path.
We are actually "accelerating" upwards at a constant rate that is equal to what we feel and many think of as gravity. This is because spacetime is curved by the mass of the earth.
Think of a grid being distorted or squeezed / pinched. The distortion pinching is "gravity". Everything in the grid still travels in a straight path relative tot he lines on the grid but since the [spacetime] grid is pinched, it looks as if it is not on a straight path.