What's with gasses compressing other gasses?

[psusi]

I have this chamber near the surface that started with some polluted oxygen in it from the ph20 there evaporating, and the heat from all of the falling regolith has boiled much of the water filling the room with over 120 kg/tile of steam.  As you can see, some of the po2 on the left has been squeezed into a single tile now at ~128 kg, but there is still a sizable pocket on the right that is still sitting at only 4 kg/tile.  Why has the steam not compressed that po2?

[Neotuck]

you have a gas lock happening right here

PO2 is lighter than steam and will rise to the top

but with only 1 tile gap there is a choke point under the POI tiles, the PO2 can't rise and as long as there is equal PO2 pressure next to it, then it won't move.  It won't matter how much steam is under it

[Gurgel]

It is a consequence from the fact that in ONI only one gas/liquid/solid can fill a tile. The way gases move is, I think,  that neighboring tiles exchange contents under some conditions. Don't know exactly what is needed, but I think after the exchange, the neighbors must have tiles with the same gas afterwards as before or something along these lines. That allows, for example, a tile of CO2 to move left, right and sometimes down in Oxygen and causes it to eventually end up at the bottom. In your example, it prevents movement, as the steam-tile would have a different set of neighbors after a swap upwards.

Does anybody know what the exact rules for gas moving through gas are?

[psusi]

So high gas pressure can only push other gasses directly up or down, not side to side?  It sure doesn't seem to work that way when you turn on a deoxidizer; it blows about everything away, and that includes sideways.

[Neotuck]

2 minutes ago, psusi said:

So high gas pressure can only push other gasses directly up or down, not side to side?  It sure doesn't seem to work that way when you turn on a deoxidizer; it blows about everything away, and that includes sideways.

It can't do both at the same time

In other words it can't do an L shaped bottle neck only 1 tile thick

[psusi]

5 hours ago, Neotuck said:

It can't do both at the same time

In other words it can't do an L shaped bottle neck only 1 tile thick

So you mean it can only push a tile of other gas out of the way if it only touching one other tile of that same gas?

[Neotuck]

56 minutes ago, psusi said:

So you mean it can only push a tile of other gas out of the way if it only touching one other tile of that same gas?

bingo, that's why "U" shaped CO2 airlocks work

[psusi]

10 hours ago, Neotuck said:

bingo, that's why "U" shaped CO2 airlocks work

I thought U worked because the heavier gas couldn't be pushed up by the lighter gas.

[Neotuck]

14 minutes ago, psusi said:

I thought U worked because the heavier gas couldn't be pushed up by the lighter gas.

It's the same principle

[psusi]

Just now, Neotuck said:

It's the same principle

No, it isn't.  If the principal is simply that the heavier gas sinks, and can sink no lower than the bottom of the U, that works for the U, but not for my L since the PO2 should be trying to rise or move sideways since it is lighter.  The fact that it can do both shouldn't matter.

[impyre]

Edit: derp

[Neotuck]

the bottom of the U is two tiles high

what prevents the CO2 from being compressed to the bottom tile that would allow high gas pressure to escape?

think about it

[psusi]

31 minutes ago, Neotuck said:

the bottom of the U is two tiles high

what prevents the CO2 from being compressed to the bottom tile that would allow high gas pressure to escape?

think about it

Oh yea, there's a T of CO2... and the side of the T won't move over because it would still be touching CO2 on both sides?  So... how does a pocket of CO2 ever sink in an otherwise oxygen room?  Why isn't it prevented from moving the oxygen below it out of the way because it is touching other oxygen on multiple sides?

[Neotuck]

2 minutes ago, psusi said:

Oh yea, there's a T of CO2... and the side of the T won't move over because it would still be touching CO2 on both sides?  So... how does a pocket of CO2 ever sink in an otherwise oxygen room?  Why isn't it prevented from moving the oxygen below it out of the way because it is touching other oxygen on multiple sides?

gases will "trade places" if a heavier gas is on top of a lighter gas, they will also do the same to the sides but less frequently 

the only time they don't "trade places" is if the heavier gas is on the bottom

[Gurgel]

45 minutes ago, Neotuck said:

gases will "trade places" if a heavier gas is on top of a lighter gas, they will also do the same to the sides but less frequently 

the only time they don't "trade places" is if the heavier gas is on the bottom

Actually, they seem to swap more to the sides. At least CO2 in Oxygen does from observations in my base.

[Neotuck]

2 minutes ago, Gurgel said:

Actually, they seem to swap more to the sides. At least CO2 in Oxygen does from observations in my base.

well I don't know the % rate of how often they swap, only thing I know for sure is heavy element gases never swap up with lighter element gases

[Gurgel]

30 minutes ago, Neotuck said:

well I don't know the % rate of how often they swap, only thing I know for sure is heavy element gases never swap up with lighter element gases

That is definitely true.