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[DreamThorn]

I've searched around a bit, found many references to it, but no description.  What is the lignite-in-a-bin trick?

My imagination says that I somehow put a piece of somehow-burning lignite into a bin, and throw the bin into the sea, and this boils a hole in the sea.  Or what?

[Areyar]

superheated steam is also only possible under pressure. e.g. in a sealed volume.
Heating a liquid (or gas) globule in a variable volume will only have it increase it's volume. Boyles law: V*P/T = Constant or for a ideal gas: PV = nRT, nb increase temperature and the product of pressure and volume will increase, usually pressure is exchanged for more volume, so that internal pressure is equal to external pressure. Point is equilibrium is maintained.
Consider also the cold that is created by releasing the pressure from a CO2 canister (actually increasing the volume of CO2 through a narrow opening) compared to the heat that is generated if you abuse a bicycle pump.

[/pedantmode]

[decius]

superheated steam is also only possible under pressure. e.g. in a sealed volume.
Heating a liquid (or gas) globule in a variable volume will only have it increase it's volume. Boyles law: V*P/T = Constant or for a ideal gas: PV = nRT, nb increase temperature and the product of pressure and volume will increase, usually pressure is exchanged for more volume, so that internal pressure is equal to external pressure. Point is equilibrium is maintained.
Consider also the cold that is created by releasing the pressure from a CO2 canister (actually increasing the volume of CO2 through a narrow opening) compared to the heat that is generated if you abuse a bicycle pump.

[/pedantmode]

Umm... superheated steam is steam which is heated above the boiling point. Pressurized steam is steam which is above outside pressure. You can have steam which is pressurized, or superheated, or both, or neither. Steam at 1 bar and 120 C is superheated.

Steam is not an ideal gas. If you decrease temperature or volume (keeping mass constant) enough, it will condense.

In steam systems, volume is normally constant. (Boilers being made of strong metals and all). Superheating may or may not be used, and the steam may or may not be pressurized.

Don't confuse -changing- the boiling point of water with getting liquid water above the boiling point. Yes, it's possible to get water into a metastable state, but not ice.

"Cold" is not generated. Boiling CO₂, as well as expanding gases, absorbs heat from the surroundings. That reduces temperature.

If you're going to be pendantic, be reasonably accurate.
[/pendantmode]
[ontopic]
Every application I can think of for pressurized gases is outside the technology level limit. Why the push for modeling gas pressure? I'd love to carve a watt engine out of stone rooms, or make a magma-powered steam lift pump, but it's just as thematically inappropriate as canister shot.

Will we see implementations of latent heat as well as sensible heat? (I think I saw a 'specific heat capacity' value in the raws) Will magma lose its property of "always hot", and cool through methods other than having water dumped on it?

[Areyar]

heh. jep.
 

I'd rather have balances, ropes and counterweights than steampower etc.
and bucket lifts.

[Footkerchief]

Off topic:

I like your current avatar, Foot.

Brad Neely is the man.  So is Babycakes.

Haha, thanks.

Every application I can think of for pressurized gases is outside the technology level limit. Why the push for modeling gas pressure? I'd love to carve a watt engine out of stone rooms, or make a magma-powered steam lift pump, but it's just as thematically inappropriate as canister shot.

I don't think it's worth prioritizing, but there's a small chance it could get implemented mostly "for free," depending on how some pathfinding stuff goes.  Namely, if pathfinding goes the route of using multiple connectivity maps, the fliers' map could probably used to figure out pressure-sealed areas, and then you could have a table that says map component X has Y oxygen and Z other gases, along with total volume V. 

So you could do suffocation, and there might even be a way to exert static forces on "plugs," so a weak door would snap from the pressure differential or something.  Suffocation traps would be fun.

Will we see implementations of latent heat as well as sensible heat? (I think I saw a 'specific heat capacity' value in the raws) Will magma lose its property of "always hot", and cool through methods other than having water dumped on it?

Very old and possibly obsolete quotes:

Water hardens magma, and it doesn't take very much.  This is because it doesn't track the magma's current temperature -- if it did that, it would just cool off and not work as people want it to work in terms of violent weaponry and so on.  I might look at it more later on.  Right now it's fairly simple of necessity, but you can cool it off with water contact.

Stone walls don't melt right now, because the lava doesn't raise the temperature of adjacent squares up to the melting point of stone -- doing so would set up a chain reaction, since it doesn't distribute the heat from fantasy lava realistically.  Fantasy lava doesn't cool off quickly unless it is watered.  Also, because of this, I don't think I even bothered running temp checks on stone walls, though it'll probably happen at some point.

More recent:

I don't have thermal conductivity at this point, so I think it mostly just ends up using specific heat for any transition questions.  Might need to add it later, but I don't really want to complicate temperature further at this point, since it's already a huge bottleneck.

I'd rather have balances, ropes and counterweights than steampower etc.
and bucket lifts.

There was a Suggestions thread about winches a while back.  I remember it cause I got enthusiastic about some of the OP's ideas and fleshed them out further.  However, making them useful would probably be hard.

[CobaltKobold]

There was a Suggestions thread about winches a while back.  I remember it cause I got enthusiastic about some of the OP's ideas and fleshed them out further.  However, making them useful would probably be hard.

Mine elevators. Drawbridges. Portcullises.

useful: Simple way to access underground with power (or manual labor) while keeping nonfliers from getting back to you unauthorized.

[Untelligent]

I spent a long time looking at all the stuff about the materials rewrite merely thinking that is was, while cool, a fairly massive expenditure of effort for very little gain to the player.

Not if the player also happens to be a modder.

Drawbridges.

 We already have those.

[Footkerchief]

Drawbridges.

 We already have those.

Of course, but they don't make any sense right now.  They just magically raise themselves at the pull of a lever.

[Mephansteras]

The material rewrite does a few other things for the player as well. Megabeasts will now be much tougher, both in World Gen and in actual play (a common complaint). Missile weapons will no longer be quite as ridiculous, and I think things like socks and coins will no longer be valid weapons in most circumstances. All of that is going to have a significant impact on things. It was also necessary for poisons and health care to be reworked, and those should have a pretty big impact on the next version as well.

Of course, modding is going to get a huge boost, and I expect we'll see a lot of amazing things come from the community.

[HLBeta]

Every application I can think of for pressurized gases is outside the technology level limit. Why the push for modeling gas pressure? I'd love to carve a watt engine out of stone rooms, or make a magma-powered steam lift pump, but it's just as thematically inappropriate as canister shot.

As I see it, the fundamental problem with trying to enforce a technology level this way is that it demands that the game overlook natural laws to keep the player from doing something screwy. You should be able to pressurize and/or superheat materials because the capacity to do so has always existed regardless of any technological capability to make use of that fact. Where things start to get silly is when the player begins to make use of the advanced mechanical capabilities to create metatechnologies and complex mechanisms. There is no conceivable reason for a Dark Age society to spend years of labor and a great deal of specialist expertise to construct a water-powered calculator the size of a mountain, yet the player can and should be able to construct crude logic gates because the potential of constructing a logic gate has always existed. As more physical properties and simple mechanisms are implemented it is inevitable that Dwarven society will climb ever further beyond its world's presumed technology level and I feel that attempting to retard such progress is unwise and directly counter to the spirit of the game. We've already seen devices for precision magma bombings, simple addition, an aquarium tower that can be readily converted into a carp-filled deathtrap and back again. The "technology level" concept went out the window with the first mechanist's workshop and I see no reason to try to reinstate it now.

I'm not saying that my dwarfs should all own flying cars by version one, just that it should be possible to exploit many or all of the basic physical principals of the universe even if I must do so with the current pump-floodgate-drawbridge level of technology. I don't need gunpowder to make a cannon. All I should ultimately need is a pair of remotely controlled airtight floodgates, a large block of ice, a magma flow, a tunnel and a large rock. An erupting volcano operates in a similar manner, albeit with much grander scale and slightly different materials. I'm fine if it never becomes possible to synthesize gunpowder, it is merely an explosive for the uncreative. Give me a few simple machines and some physics and I will be happy.

[Neruz]

Plus, high pressure gases, superheated gases and high pressure superheated gases are real-world mining problems, problems that can only possibly be made worse when you are mining through a Volcano to get at the delicious magma inside.

[Dante]

As Untelligent just alluded to, with lever-bridges, the whole "era-appropriate technology" thing is already kind of hazy when it comes to the entire field of dwarven mechanics. All that action-at-a-distance, automagical weapons traps, and so on. That on top of handwaving such as building a windmill from four logs.

In the face of slightly weird stuff like this, I don't see why Toady would leave out stuff that actually follows the laws of physics. Whether dwarves should be allowed to harness it is another question.

[CaptainNitpick]

I've searched around a bit, found many references to it, but no description.  What is the lignite-in-a-bin trick?

My imagination says that I somehow put a piece of somehow-burning lignite into a bin, and throw the bin into the sea, and this boils a hole in the sea.  Or what?

You want the "Stupid coal tricks" thread.

[Quatch]

...
 I'm fine if it never becomes possible to synthesize gunpowder, it is merely an explosive for the uncreative. Give me a few simple machines and some physics and I will be happy.

Thats what I was trying to say. Well put.

[numerobis]

Also: usefull steam power dates from the late 1600's.

The Arabs were using steam to spin their gyros by the 12th century AD.