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[Neruz]

It's the only explanation i can come up with for things that boil at very low temperatures instantly freezing dwarves; logically the things in question should be steam at room temperature and thus harmless to dwarves, yet instead it instantly causes dwarves (and other animals) to be frozen.

I can't think of any other explanation other than 'materials cannot get hotter than their boiling temperature.'

[DreamThorn]

The way I understand the temperature system, each square/cube has a temperature that is simulated and which causes objects to have phase transitions, but the actual objects do not have temperatures associated with them, which is why it has to use the boiling temperature for the gaseous form.

[Neruz]

Creatures have temperatures associated with them, i'd assume objects do to.

Although it's possible they don't to save on CPU. Doesn't really explain why the temperature in a square goes down to the temperature of the boiling object and then goes back up again after the boiling material has gone way.

[Another]

I guess that when a phase transition occurs the blob or cloud of material is assigned the exact temperature of phase transition (which is reasonable from a physicist's point of view) and then is farther heated or cooled down by interacting with environment using its heat capacity. What is currently missing, I believe, is heat required to carry out the transition from one state to the other. As was already pointed out most damage from steam is not really from its temperature but from the heat when it condensates on bodies.

Ultra-cold gas abnormalities happen because having normal gas heat capacity it requires lots of heat to get to room temperature and it is not compensated by making it emit adequate amount of heat in the transition. Animal leather gases are exotic in that they have enormous amounts of internal energy at room temperature. A solid object that is much hotter then its boiling temperature should have great amounts of internal pressure and be deadly anyway.

[Laiska]

Now with the ladders incoming, giving the different nature of these constructions i see more fun.
Huge dark cavern with a newly crafted *kitten-skin-rope-ladder menacing with picture of kitten. kitten is adopting a dwarf.* hanging 5 floors from top to bottom. Several dwarfs climb it upward carrying spoils of newly discovered lead vein, when the 1st one gets struck by a strange mood, drops the stone of lead and rushes upward babbling. 2nd on on line is struck unconsious of the falling rock, releasing the grip, and the rocks and dwarfs fall in perfect silence.

[smjjames]

As far as we know, Toady has only said that the rope ladder thing is still bieng considered. I'm sure he is aware that the community is mainly willing to accept a hacked together placeholder and that it is pretty important to the way the new stuff is.

[Footkerchief]

I don't think it came up in this round of discussions, but rope ladders also present special problems regarding who/what should be able to climb them.  As a result, proper rope ladders are completely out of the question for this release. 

Yeah, it's a bit odd to build staircases from above, though it's unclear what will happen in the end.  If I do add ropes, all critters will probably be able to use them, because I don't have more control over path-finding.  Hopefully that will change at some point, but it's not as urgent a concern as being able to get down into open spaces, which will be a pressing matter for this release.

It's more of a technical matter.  I know how to check for grasps, etc., but it doesn't matter.  There will be catastrophic lag if animals can't climb ropes, since the game can't handle path restrictions that don't affect everybody (locked doors, etc.), once you are down to dwarf-style movement.  The sorts of general, sweeping pathfinding rewrites which will need to happen eventually but which are incredibly time-consuming are the only fix here.

It was actually a bit depressing looking over that previous discussion -- I don't think anything new got mentioned this time around.

[decius]

I guess that when a phase transition occurs the blob or cloud of material is assigned the exact temperature of phase transition (which is reasonable from a physicist's point of view) and then is farther heated or cooled down by interacting with environment using its heat capacity. What is currently missing, I believe, is heat required to carry out the transition from one state to the other. As was already pointed out most damage from steam is not really from its temperature but from the heat when it condensates on bodies.

Ultra-cold gas abnormalities happen because having normal gas heat capacity it requires lots of heat to get to room temperature and it is not compensated by making it emit adequate amount of heat in the transition. Animal leather gases are exotic in that they have enormous amounts of internal energy at room temperature. A solid object that is much hotter then its boiling temperature should have great amounts of internal pressure and be deadly anyway.

Um... how would you get a solid object hotter than its melting point, much less its boiling point? Doesn't it, well, melt and boil at that point?

One issue is that changing the raws creates physically impossible situations. Another is that melting and boiling seem to happen instantly. Certainly putting buckets of ice in a room will reduce the temperature of the room. It just won't happen instantly, nor will melting ice ever reduce the temperature of the room to the melting point of the ice. (You can't make something that is currently hotter than you colder than you, or vice versa.)

And refrigeration systems more advanced than mining ice are beyond the technology barrier. Also: usefull steam power dates from the late 1600's.

[Quatch]

And refrigeration systems more advanced than mining ice are beyond the technology barrier. Also: usefull steam power dates from the late 1600's.

While this may be a strong argument against coding it first, the physics (and thus game engine mechanics) aren't something that suddenly worked after it(steam, gunpowder, etc) was invented.

Also, evaporative cooling, very old.

[Areyar]

Um... how would you get a solid object hotter than its melting point, much less its boiling point? Doesn't it, well, melt and boil at that point?

Under standard circumstances, yes.
However, by increasing the ambient pressure, the boilingpoint rises too. So the first poster is right: a solid above it's boilingpoint (standardised conditions) will be unstable and prone to sudden phase transition. Not that this will occur very often.
Example: 'boiling retardation' in water, as when heating water in a microwave. I guess the mechanism here is surface tension boosted by hydrogenbonds that supresses evaporation nuclei from forming and thus boiling to occur.
Another water example of pressure influence on EP is boiling water in airplanes vs submersibles.  Lower pressure == lower boilingpoint , higher pressure == higher boilingpoints.

[Neruz]

You can also heat the vapours themselves beyond boiling point; alot of steam cookers use superheated steam to cook things (which is why they cook so fast.)

[HLBeta]

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. Then it hit me. This is not some example of coding pedantry, but a critical step towards making it possible to weaponize a quantum dump. Imagine if you will a single tile chamber at the bottom of a shaft, surrounded by a constantly flowing stream of fresh magma transferring heat through the walls. As objects are thrown down, the intense heat will melt most of them, whereupon a screw pump forces the resultant fluid into a second heated chamber full of similar fluids. Due to the intense pressure of so many molten-hot objects in the chamber, it should be a relatively simple matter to violently evaporate/sublimate the entire mass by dropping a floodgate, burning any goblins in your entryway to a cinder and repainting the room with the awesome power of Dwarven Recycling.

This is my vision of Version One.

I would also greatly enjoy being able to apply metal leaf to the walls and floors of rooms by a similar process.

[Jimmy]

I wonder what's gonna happen with the current "lignite-in-a-bin" trick after all the changes?

[Warlord255]

I wonder what's gonna happen with the current "lignite-in-a-bin" trick after all the changes?

I think that has more to do with the bin's "shielding" of the block, but we'll see.

[Sunday]

Off topic:

I like your current avatar, Foot.

Brad Neely is the man.  So is Babycakes.