This thread REALLY needs to be put to bed.
This is a case when most of the RE'ers here are talking bullshit.
(Of course, what the FE'ers are talking is also bullshit - but that's a given.)
FACT #1: Einstein's theory of GENERAL relativity (not "SPECIAL") says that there is no possible way to tell the difference between a uniform acceleration and a uniform gravitational field. This is true - it's been proven a hundred different ways. The FE'ers are correct...and a majority of the RE'ers who say otherwise are wrong(!!).
FACT #2: The FE'ers claim that the flat earth is accelerating upwards at a uniform 9.8 m/s/s would indeed produce EXACTLY the same effect as a uniform gravitational field is also correct.
FACT #3: The Earth's gravitational field is NOT uniform...so facts #1 and #2 are not 100% applicable to the real world. How do we know this? We know that things weigh less at the equator than at the poles. We know that things weigh less at the tops of tall mountains than at sea level. We know that things weigh more in areas where there are concentrations of dense rocks (granite, for example) and less over rocks like volcanic pumice.
FACT #4: We clearly observe that tides are caused by the moon being overhead - AND by being overhead 12 time zones away (choosing my words carefully here!)...and to a lesser degree by the sun being overhead and overhead 12 times zones away. This fits the RE claim that the sun and moon are both sources of gravity...and as a direct result of this, the total gravitational field here on Earth's surface is not uniform.
FACT #5: If the Earth's gravitational field is NOT uniform - then Universal Acceleration (which MUST be uniform) cannot adequately explain the effects we see in FACT #3 and #4 without some modifications...because General Relativity doesn't apply on larger scales - only in small situations where the gravitational field is so nearly uniform as to not matter.
So, what do the FE'ers do to try to fix this?
* They (mostly) claim that UA affects some unknown "thing" deep underground that is pushing upwards on the Earth's crust, and on the sun, moon, stars and planets.
* I've seen others claim that there is also some "celestial attraction" (CA) force pulling UPWARDS on sun/moon/stars/planets instead. It really doesn't matter which they claim if CA is a uniform field like UA - the end results would be identical - the total of (UA-CA) is the same as just having a slightly smaller UA. So this concept is only meaningful if CA is not a uniform field...it would need to be like gravity (stronger as you go upwards) in order to keep the sun/moon/stars/planets in place.
* Yet others claim that air pressure is responsible for the weight of objects and that they fall when you drop them. This is so clearly nonsensical - one hardly knows where to start with it! Put an object inside a bell-jar, pump out all of the air, does it float around inside the jar? No, it doesn't. Theory **BUSTED**.
* The UA-but-not-CA'ers also claim that earthly objects (your body, rocks, dirt, air, ocean, tables, airplanes)...are NOT being pushed upwards by UA - which is why a rock falls to the ground when you drop it. It's a bit arbitrary to have a force that affects some things but not others - but it's their theory - so we can allow it if it works.
* The UA plus CA'ers can claim that only the Earth itself is being accelerated upwards - and that everything else is affected by CA.
But this doesn't explain the changes in the weights of objects at the equator and on tall mountains or over denser rocks. It also doesn't explain the two lunar tides we clearly see every day (or the two small additional effects from tides caused by the sun). It also doesn't explain why asteroids sometimes fall to earth as meteors...are they affected by UA/CA or not? The mathematics behind how CA increases with altitude could also bear investigation...but I'm OK with it.
Hence they need to modify their claims a bit to try to "fix" these problems in their theories.
* Some FE'ers claim that the sun and moon DO have "gravitation" (although for some bizarre reason they refuse to use the simpler word "gravity"?!?!?)...which they claim explains the tides and the reduction in the weight of objects at the tops of mountains.
* Some have claimed that "celestial attraction" is pulling upwards more strongly on objects at the tops of mountains than at sea level - which explains the reduction in weight for objects at the tops of mountains.
* Some have claimed that the reduction in air pressure at the tops of mountains explains the reduction in weight of objects there...but that's ridiculous...air pressure pushes equally in all directions - not predominantly downwards...so this is B.S.
Trouble is - not one of these "explanations" explains the fact that there are TWO lunar tides per day. If the moon pulls up on things because of gravity...er..."gravitation"...then there would only be one high tide per day...not two. When the moon is 12 time zones away - it might pull the water sideways - but that would only reduce the water levels where I'm standing - it couldn't increase it. Ditto for the additional effect of solar tides.
So the pile of wobbly/iffy FE claims CANNOT simply be dismissed by asking about people jumping off of chairs or digging up rocks.
That makes this thread STUPID because BOTH sides are missing the key points of the argument.
RE'ers: The ONLY things you can say to dismiss UA are relating to non-uniform gravitational fields - which you can't see in "room-sized" experiments because the gravitational field on that scale is so very close to being uniform. You have to address things on large scales like poles versus equator or mountains versus sea level or tides. Your attempts to "disprove" FET using small scale arguments will fail...and rightly so.
FE'ers - you still can't explain two tides per day or different weights of objects at poles and equator...so your arguments fail too...and rightly so.