[MonroeDNA]

Not trying to be arguementative, if I come across that way.

I guess my point is that accelleration is always 2-D, while gravity is 3-D. They can ALWAYS be distinguished from each other. They are not the same, and under ANY circuimstance imagined, they can be easily distinguished.

[RightWhale]

accelleration is always 2-D

Not at all. Spacecraft have control thrusters pointing along 3 axes and they can impart a 3-D acceleration. In the superstring model there can be more than 3 dimensions, maybe even 11 in some cases, and there could be corresponding accelerations.

[Gary Boldwater]

How about examining the DeBroglie wavelength to tell the difference between a gravity field and acceleration? According to popular science (not the magazine, please) an accelerating object would have a DeBroglie wave and a stationary object would have none (even in a gravity field). The real question is: motion relative to what?