Add solid/liquid/gaseous portions of matter

[l-emele]

Description of the issue

A lot of our portion of matter subclasses have solid, liquid, gaseous (normal) states of matter. I would be nice to create equivalent classes that catch all of the respective portions of matter classes by their states. This would be a nice extension of our multihierachy in the portion of matter part of the OEO.

Ideas of solution

As we distinguish between has state of matter and has normal state of matter we should distinguish between solid/liquid/gaseous portion of matter and solid/liquid/gaseous portion of matter under normal conditions:

• solid portion of matter:
  • A solid portion of matter is a portion of matter that has a solid state of matter.
  • 'solid portion of matter' EquivalentTo: 'portion of matter' and 'has state of matter' value solid
• liquid portion of matter:
  • A liquid portion of matter is portion of matter that has a liquid state of matter.
  • 'liquid portion of matter' EquivalentTo: 'portion of matter' and 'has state of matter' value liquid
• gaseous portion of matter:
  • A liquid portion of matter is portion of matter that has a liquid state of matter.
  • 'gaseous portion of matter' EquivalentTo: 'portion of matter' and 'has state of matter' value gaseous
• solid portion of matter under normal conditions:
  • A solid portion of matter is a portion of matter that has a solid normal state of matter.
  • 'solid portion of matter under normal conditions' EquivalentTo: 'portion of matter' and 'has normal state of matter' value solid
• liquid portion of matter under normal conditions:
  • A solid portion of matter is a portion of matter that has liquid normal state of matter.
  • 'liquid portion of matter under normal conditions' EquivalentTo: 'portion of matter' and 'has normal state of matter' value liquid
• gaseous portion of matter under normal conditions:
  • A solid portion of matter is a portion of matter that has a gaseous normal state of matter.
  • 'gaseous portion of matter under normal conditions' EquivalentTo: 'portion of matter' and 'has normal state of matter' value gaseous

In natural language, there is solid as adjective and a solid as noun and likewise liquid and a liquid. To catch this ambiguity we might think about adding the alternative labels:

• solid to solid portion of matter and solid portion of matter under normal conditions
• liquid to liquid portion of matter and liquid portion of matter under normal conditions
• gas to gaseous portion of matter and gaseous portion of matter under normal conditions

Further, we might add

• normal state of matter: A normal state of matter is a state of matter that occurs under normal pressure (1 bar) and normal temperature (0°C).
  This proposal aligns with the already existing object property has normal state of matter: x has normal state of matter y if and only if a portion of x occurs in state y under normal pressure (1 bar) and normal temperature (0°C)

Workflow checklist

• I discussed the issue with someone else than me before working on a solution
• I already read the latest version of the workflow for this repository
• The goal of this ontology is clear to me

I am aware that

• every entry in the ontology should have a definition
• classes should arise from concepts rather than from words

[u-mueller]

I like this idea very much, and to me it seems a good way to enrich the ontology with axioms.

[l-emele]

@stap-m : Any thoughts on this issue?

[stap-m]

Straightforwardly derived and definitely nice to have.

[u-mueller]

Shall I implement, @l-emele, to get some more practice?

[l-emele]

Yes, please implement. 🚀

[u-mueller]

Again a question that arose while implementing: Shouldn't be solid portion of matter under normal conditions be a subclass of solid portion of matter etc. as normal state of matter is a subclass of state of matter -- with respective reference to parentclasses in the definitions?
The EquivalentTo: axioms may stay as proposed.

[l-emele]

That was also my initial thought, but that is wrong. Take water: it has a normal state of matter liquid, but we do not specify which state of matter it is. But water has two subclasses: liquid water and steam ¹. Both liquid water and steam have the normal state of matter liquid but only liquid water has the state of matter liquid while steam is gaseous. After implementing the equivalent classes, the inferred hierarchy should look like this:

• liquid portion of matter
  • liquid water
  • liquid air
  • ... other classes ...
• liquid portion of matter under normal conditions
  • water
    • liquid water
    • steam
  • ... other classes ...

But to me, your question raises a different question: We currently use axioms like 'liquid water' 'has state of matter' value liquid and 'natural gas' 'has state of matter' value 'gaseous' to describe the state of matter the substance currently is in.
But do we need here something like a has actual state of matter or has current state of matter or something like that?

If we follow this proposal, we would then have the following object properties:

• has state of matter
  • has normal state of matter
  • has actual/current state of matter

If we do should, we would change the axioms mentioned above to:
'liquid water' 'has actual/current state of matter' value liquid
'natural gas' 'has actual/current state of matter' value 'gaseous'

In the end we would probably only have one axiom using the (parent) object property has state of matter:

• 'portion of matter' 'has state of matter' some 'state of matter', which basically follows from the definition.²

All subclasses would get either has normal state of matter axioms or has actual/current state of matter axioms or both.

To avoid creating a parallel structure of maybe we should abstain from adding normal state of matter and actual/current state of matter classes and have only object properties? In the end, solid, liquid and gaseous are in fact properties of some substances.

Sorry for the long answer to a seemingly short question. Sometimes in ontology work, you touch a little thing but reveal a major hole in the whole internal logic 😄.³

Footnotes

1. And it should also have a subclass (water) ice but we did not implement this yet. ↩

2. A portion of matter is an aggregate of material entities that have a state of matter. ↩

3. This wisdom from xkcd seems to hold not only for the whole internet but every larger aggregate of information. ↩

[u-mueller]

Thanks for your long answer (and the funny cartoon:-). Water is an enlightening example (though a bit tricky, too, if you look closer at its state under normal conditions). I would then prefer to abstain from adding normal state of matterand actual state of matter. Right now, I have an issue with Protégé, I try to fix it and then implement.

[stap-m]

But to me, your question raises a different question: We currently use axioms like 'liquid water' 'has state of matter' value liquid and 'natural gas' 'has state of matter' value 'gaseous' to describe the state of matter the substance currently is in.
But do we need here something like a has actual state of matter or has current state of matter or something like that?

Would that imply more than a relabelling? I mean, "normal state of matter" is clearly defined and any other state of matter is related to a current state or state under "usual application conditions". E.g. 'liquified natural gas' 'has state of matter' some liquid. I don't see the advantages, yet.

To avoid creating a parallel structure of maybe we should abstain from adding normal state of matter and actual/current state of matter classes and have only object properties?

Do you mean smth like 'liquified natural gas' 'is liquid under conditions' some 'application conditions' and 'liquified natural gas' 'is gaseous under conditions' some 'normal conditions'?