Gravity is a bending of space-time caused by mass (in some sense even identical to mass). The same for acceleration. Gravity and acceleration are the same thing. This observation is the basis for Einstein’s General Theory of Relativity. (Relative) Motion is an effect of gravity but not its cause. What Arlo says is nonsense, and Janis’ reply is right on.
Gravity is a bending of space-time caused by mass (in some sense even identical to mass). The same for acceleration. Gravity and acceleration are the same thing. This observation is the basis for Einstein’s General Theory of Relativity. (Relative) Motion is an effect of gravity but not its cause. What Arlo says is nonsense, and Janis’ reply is right on.