Please look up the Equivalence Principle, it should answer any questions you might have of this nature. It was Einstein who said that the effect of gravity was equivalent to that of a constant acceleration, not us.

Yes, I have looked up the Equivalence Principle in the Wiki and elsewhere and maintain that it

**cannot be legitimately applied to the whole earth.**The article at this website

http://worldnpa.org/abstracts/abstracts_6546.pdf is really a very telling article on the Equivalence Principle and should be read before anyone criticises too severely what I put here.

In its simplest from the FET uses the

*Equivalence Principle* to replace the

*gravitational field* observed on the earth's surface. I contend that this is not a valid application of the

*Equivalence Principle*.

*we [...] assume the complete physical equivalence of a gravitational field and a corresponding acceleration of the reference system.*

— Einstein, 1907

This very brief statement of Einstein needs a little qualification. If the

*reference system* under consideration is not small enough for the

*gravitational field* to be considered constant over its range then there can be no

*complete physical equivalence*.

This is stressed in the fuller presentation of the Equivalence Principle.

*An equivalent formulation of the Principle of Equivalence is that at any local (that is, sufficiently small) region in spacetime it is possible to formulate the equations governing physical laws such that the effect of gravitation can be neglected. This in turn means that the Special Theory of Relativity is valid for that particular situation, and this in turn allows a number of things to be deduced because the solution of the equations for the Special Theory of Relativity is beyond the scope of our course, but is not particularly difficult for those trained in the required mathematics.* from http://csep10.phys.utk.edu/astr162/lect/cosmology/equivalence.html

In the case of the earth we can readily measure variations in the

*gravitational field*. The most obvious is due to altitude and latitude, but there are more subtle variations due to the presence of ore bodies as used in gravimetric surveys for minerals.

As a result this, the concept of

*Universal Acceleration* can replace a

*gravitational field* only if the

*reference system* (the whole earth) is sufficiently small for the

*gravitational field* to be considered constant over the whole system.

**This is clearly not satisfied, so the concept of Universal Acceleration cannot be be used to replace the gravitational field.** and shows quite clearly that

**UA is simply an invalid substitute for the observed "gravitational field"**.

I know that TFES attributes these variations to the "gravitational effects of the celestial bodies", as in:

*Q: Why does gravity vary with altitude?*

A: The moon and stars have a slight gravitational pull.

**but this cannot be the cause because these bodies are in constant motion above the earth**, yet the variations in the observed "gravitational field" because these variations are essentially stationary - being due to altitude, latitude and the proximity of massive ore bodies, etc.