Another thing that I am having trouble with here scepti, is that you need a different explanation every time something in the system changes.
Yes, a different explanation but the end result is always the same in that it's high versus low pressure, every time and this is key to grasping it all.
Getting push back in your seat is caused by air moving to the back of the bus.
It's the bus going faster than the air, leaving it behind from front to back which creates the low pressure at the front as it all compresses all the way to the back and that low pressure HAS to be equalised all of the time. So acceleration gradually is always creating a low pressure which is always filled, creating more compression and putting your sea level adjusted body under stress which is forcing you back for as long as the acceleration lasts.
Items on a table getting the tablecloth pulled out from underneath them are pushed up in the air by a low pressure underneath them.
This where speed is key. The table cloth is being pulled faster than the air it's in and it creates a low pressure under the items as it moves that is immediately equalized and because it happens so fast you don't notice that the items become like skates on ice, it's sort of like a nano second levitation for each iten that the cloth passes under.
Where as inertia explains both of those scenarios.
If you are serious about finding out about this stuff, the you need to pick up both of those words, inertia and gravity and put them in a nice hiding place so they allow you to concentrate on the reality.
If you are not satisfied that atmospheric pressure is the reason, then get them back out and stick to them.
Also, I was having a think about air pressure causing what we perceive as gravity.
If, as you claim, it is caused by the downward pressure of the atmosphere, what would happen if you had a block of steel that was 1ftx1ftx2ft. You weigh it standing on end so that one of the 1fx1ft sides is up. Then you weigh it where one of the 1ftx2ft sides is up.
Does the block weigh any different? If so, why? If not, why?
No it wouldn't make any difference. It is part of the atmospheric pressure to start with, as are the scales, so it's still displacing the same amount of air pressure so the same amount will act on it.