Einstein's equivalence principle states that the effects of gravity are indistinguishable from the effects of acceleration. A person standing in a closed elevator on the surface of the Earth cannot...
Einstein's equivalence principle states that the effects of gravity are indistinguishable from the effects of acceleration.
A person standing in a closed elevator on the surface of the Earth cannot distinguish, through any local measurement, between the gravitational pull of the Earth and the acceleration of the elevator through space at 9.8 meters per second squared.
The two are locally identical. The person feels the same weight. The person's physics experiments produce the same results. The distinction between gravity and acceleration is not a local fact.
It is a global interpretation - an explanation that depends on knowledge of the larger context. The equivalence is not a trick of perception. It is a deep structural identity.