It is say when an astronaut is in a spaceshuttle orbiting the Earth, he feels "weightless". My physics teacher says that is not true, he said that it is mere the sensation of the astronaut not physical reality. But from my knowledge, the weighless felt by the astronaut is because of he is constantly frefalling towards earth. And according to relativity, a freefalling frame of reference is equivalent to an inertial frame of reference. So, doesn't that means that the sensation felt by the astronaut is the same as physical reality?