Hi, folks. There's a somewhat popular hypothetical situation that involves a person falling into a hole dugg all the way through the Earth or any planet, passing straight to its center. Now, I understand quite well that the resulting motion would be periodical and the reasoning behind it. My question (or questions rather) is regarding to what a person would "feel" during this trip. According to General Relativity (please correct me if I'm wrong), free falling inside a gravitational field is equivalent to uniform motion for a point particle (removing tidal effects). There is no way to distinguish one from the other without any external references. Is this true for any gravitational field or only a uniform field? Now, my primary question is this: Assuming there's no air, a perfectly symetrical and uniform body (though I think the latter is not strictly necessary) and that the person is isolated from the outside (e.g. inside a box), would a person falling through this hole feel anything different from floating freely inside the cabin? I think that with sufficiently precise instruments the person could measure tidal effects, but would the person feel anything different in different points of the trajectory? I hope I explained my self sufficiently well, my English is not the greatest. Thanks in advance.