If a reference frame of a million space craft boxes all accelerating through space at the same rate and in the same direction, all maintaining symmetrical distances between crafts, and if all of the observers born within the crafts could see no relative movement between their crafts, these observers would have no indication that they were part of an accelerating frame. What they would see would be:

 

All released objects accelerate toward the floor.

No matter what size mass released all fall at the same acceleration rate.

The floor appears to have magnetic properties.

All objects released at the same exact point will continuously strike the floor at the same point. All objects released at the same time will strike the floor at the same time.

 

If this group could communicate they might call this perceived magnetic property of the floor “gravity”.

 

The Universal Properties of Acceleration tell us that the plumb bob is all that is needed to reveal to an observer that there is an excellent chance that she is a member of an accelerating frame.

 

The Universal Properties of Acceleration tell us that there is no difference between an accelerating space ship and the surface of a planet. There is no “equivalence”, but rather “exactness”, of properties as these acceleration properties exist everywhere in the universe.

 

The question arises,... if the surface of the planet is accelerating in some kind of inflation that we cannot see, then where is all the new material coming from?

 

This question can be answered by the Universal Properties of Acceleration.