And the vaccuм of space (measured in torr) is orders of magnitude "stronger" than anything we've been able to reproduce here on earth. 

Trying to debate with you Tradman and some others, is impossible. Take for example the statement above. Are you telling me I am so silly that I think water is gas. Or, are you telling me when water is mentioned in Scripture it really means gas. Then again, over here we call something funny as 'gas.' So when water is mentioned in Scripture is it just being funny? Trying to get a 1 on 1 or a 2 on 2 debate with flat-earthers is very difficult. Anyway, I got to hand it to you guys, you have chased every global earther off the forum. If you were a little more calm and reasonable, it could be an interesting subject. Calling us satanists, heretics, stupid and so on, is not how Jesus would teach a flat Earth, is it? Now that I think of it, did He?

.  I don't buy the Einsteinian stuff about curvature of space-time.

So the common explanation (except for raw gravity) is that there not enough air pressure at the top edges of the atmosphere to push the molecules/atoms out into the vacuum, since that's actually what's happening (vacuums don't actually "suck" from a physics standpoint), but this is just kicking the can down the road, because it doesn't explain why the entropy does not cause the more dense (higher pressure) molecules to push into the less dense areas, and the only plausible explanation for this is that this is all taking place within a container with a finite volume.

If we are in a sealed container of finite volume, pressure should be equal, regardless of altitude (see Pascal's Law). Either Pascal's Law is incorrect (which it doesn't seem to be) or we're missing some factor(s).

Well, there's some force that is pushing it downwards resulting in the heavier molecules being "down" and the lighter ones going "up" ... and it isn't gravity.  Strength of gravity does not suffices to overcome entropy.  Without a container there can be NO pressure.

You can put liquids of different densities into a container, then perhaps add some gases on top of the liquids, and the heavier ones will sink and the lighter ones go up, and they form layers, and the upper layers have lower density than the higher layers.  Now put the same liquids into an open-top container and put a vacuum at the top.  Not only will the gases in the upper section evacuate, but the liquids will also turn to gas and evaporated out of the container.  Obviously how much evaporates depends on how much area there is to fill, but with alleged space, the volume is infinite.

So the pressures do not equalize depending upon the total size of the container and the total volume of matter within the container.

Nature of the firmament:
If the firmament is impermeable, we should not have a change in pressure with a change in altitude. The air may contain oxygen at low altitude and helium at high altitude but the pressure should be identical. But we've all observed that it isn't that way; anyone who has driven up or down even moderate hills has felt their ears "pop" because of a change in pressure.

If the firmament is permeable, and surrounded by negative pressure (vacuum), and the leak rate is high enough, we would see a pressure decrease at higher altitudes first, but, before long, would notice it at low altitude. Man would've died long ago.

You can put liquids of different densities into a container, then perhaps add some gases on top of the liquids, and the heavier ones will sink and the lighter ones go up, and they form layers, and the upper layers have lower density than the higher layers.  Now put the same liquids into an open-top container and put a vacuum at the top.  Not only will the gases in the upper section evacuate, but the liquids will also turn to gas and evaporated out of the container.  Obviously how much evaporates depends on how much area there is to fill, but with alleged space, the volume is infinite.

Well, there's some force that is pushing it downwards resulting in the heavier molecules being "down" and the lighter ones going "up" ... and it isn't gravity.  Strength of gravity does not suffices to overcome entropy.  Without a container there can be NO pressure.

I've agreed that there is something that has to account for the directionality of the stratification.  I just don't believe that it's gravity.  In fact, there's a video out there of a lecture given by an MIT professor who dismisses gravity as having any effect on or near the earth, asserting that the force involved is electromagnetism.

In that case the stratification could be determined based on the degree of charge on given bodies.  It's said that the earth has a negative charge.  Consequently, those elements with higher positive charge would tend to clump downward toward the earth, whereas those with lesser charge would rise higher.  Generally speaking the charge would be related too the "weight" or mass, if the charge emanates from nuclear principles.

Subsequently, if there were elements that had a negative charge, they would be repelled upward and away from the earth.  I've seen demonstrations online of electric charge being used to counteract "gravity", and of course the tech is being actively used for some of those high-speed trains.  But gravity IMO doesn't exist, and it's all somehow related to charge, to electromagnetism.

But regardless of either gravity or charge, it's never been demonstrated that either of these could counteract the power of a vacuum.  As I mentioned I've seen vacuum chambers on top of a container opened at the top, and not only was there air evacuated but the water inside the lower chamber turned evaporated.  If we are to believed that there's an nearly-infinite vacuum outside of and adjacent to the atmosphere, the atmosphere would most certainly leave the earth, and by now the oceans would have completely dried up as well.