If the equivalence principle is what I think it is, then Helium would rise in FE for the same reason it rises in RE, so this test is inconclusive.
The Equivalence Principle is, for the context of this forum, just a way to enter the General Relativity field and make some useless comments that sound very intellectual.
In reality, the EP states that you cannot distinguish between gravitational pull and acceleration locally, and "locally" depends on the precision of your experimental procedures and equipment (if you only have a metal ball and a stopwatch "locally" means many kilometers in any direction, if you have the best equipment available "locally" means only a few kilometers horizontally at most, and a few hundred meters up at most)
If you are observing two places on opposite sides of a planet or on more than one planet, for example, gravitation and acceleration are clearly discernible, so you can tell whether somebody is talking physics or doing cheap philosophy if he can predict mathematically the result of an experiment that includes two far away observed places.
Poll