[Idea] Realistic boiling points

[djdookie]

Since I started playing ONI (hundreds of ingame hours ago *g*) I wondered about why there are only normal boiling (and melting) points implemented, since the game tries to simulate a lot of real physics to a certain degree.

I know there are more things missing, like that having hydrogen floating next to oxygen is never dangerous! Or a hydrogen generator doesn't need oxygen and doesn't produce water.
But this one feels like fundamental thermodynamic rules are is broken.

In reality, as everyone knows, boiling points of liquids and melting points of solids ALWAYS depend on pressure (although for solids it doesn't make such great difference like with gases). Or the other way around: The pressure of a liquid increases if it's temperature increases.

https://en.wikipedia.org/wiki/Boiling_point#Relation_between_the_normal_boiling_point_and_the_vapor_pressure_of_liquids

Example: In the game water always boils to steam at 99.35 °C. In reality water boils at 100 °C with 1013 mbar (1 hPa) atmospheric pressure, at 110 °C with 1433 mbar and at 90 °C with 701 mbar.

Regarding all my dupe's popped eardrums, this should really make a difference in the game.

Ok we only have grams per tile as "pressure" but it's the same idea.

I can imagine several reasons why this wasn't implemented realistically:

- It's too complex/easy/hard for the player

- it's too expensive for the game engine

- it was simplified/skipped or is too hard to implement because of limited development resources

- it's coming in a later patch or DLC

Because there are a lot of great mods from great modders today, I asked myself if it's possible to mod something like this into the game and thus make it even more interesting (and challenging), and if someone would have the time and motivation to realise a realistic pressure mod.

What do you guys think?

Cheers!

[Derringer]

This might make some sense with respect to interface phase change, since unlike in whole-cell phase change there is some viable notion of pressure at the interface. Where it might run aground is the one element per cell rule. Interface phase change is quantised to 5 kg increments, so if for example 5 kg of water were to boil off under low pressure at 90 °C, it would turn to a single cell of 5 kg steam at 90 °C which would in all probability be sufficiently compressed to immediately condense again under whole-cell phase change.

Whole-cell phase change might become more problematic in general: with nowhere for steam to escape to, you'd essentially have to heat a fully enclosed tile of water enough to overcome the boiling point at its internal pressure (~1 t).

Latent heat of phase change is another can of worms. If that was applied, you'd be able to cool water by opening a steam-stack to space, and the steam turbine would have to contend with the latent heat released by condensing steam into water in addition to the sensible heat of the steam.