Talk:Q4373292

I changed the description to distinguish this from physical quantity. I believe physical property is a subclass of physical quantity that is a property of a system, specifically a property of the state of a physical system at a given time. Discussion? For example, force and work are physical quantities but not physical properties because you can't meaningfully speak of the "work of a system" or "force of a system" in themselves -- you have to do more than identify a physical system in order to measure work or force. DavRosen (talk) 07:53, 21 July 2013 (UTC)

Should a specific physical property, such as temperature, energy, entropy, charge, mass, etc., be a subclass[ of physical property, or an instance of physical property? I believe it should be instance, because each one is quantifiable/measurable in itself, not merely a class or category of quantifiable/measureable properties. On the other hand, extensive physical property is a subclass because you can't measure the "extensive physical property" of a system without saying which such property (which instance).DavRosen (talk) 07:53, 21 July 2013 (UTC)

Actually it's exactly the contrary: a physical quantity is a subclass of a physical property, because it's a particular property that can be measured by proportions (see also the article on the English Wikipedia here). — TintoMeches, 16:46, 9 November 2013 (UTC)

Uh-oh, the wikipedia articles appear to be specifically about the opposite of a chemical property!

Read some of the linked wikipedia articles -- they seem originally intended to mean physical property as distinct from (opposite of) a chemical property, which is the meaning of "physical property" taught in introductory chemistry classes, and I've changed the label and description accordingly.
A chemical property is an (intensive) property of a material -- see List of materials properties (Q2486226) which includes chemical and physical (non-chemical) properties. So the opposite of this (i.e. "physical property") is also an intensive property of a material, not just *any* property of a physical system or object, and therefore it would appear that the present item might be said to refer to a "non-chemical property of a material".
In any case, we need to distinguish the broad "property of a physical system (or object)" from "non-chemical property of a material", so, which one of these should the present item represent?? DavRosen (talk) 21:47, 8 February 2017 (UTC)

UPDATE: maybe it is too disruptive to specify one or the other for the present item, since the wikipedia articles are ambiguous and the usage within wikidata is mostly about "property of a system/object". Maybe the present item should be described as the ambiguous item that it truly has been used for: I'm changing the label back to "physical property" but the description to "attribute of a system or object; OR non-chemical property of a material". We could next create two new, unambiguous items and gradually the present item should be depracated in favor of these two. DavRosen (talk) 22:10, 8 February 2017 (UTC)

about "wikipedia articles". Wikipedia is vestigial structure (Q627214): 1) computer interface (Q23808) only for human (Q5) (human-readable medium (Q372222)), not for machine-readable medium (Q1048236); 2) URL (Q42253)-coordinates of WD-frame of reference (Q184876) - language words instead of number (Q11563). Wikidata is the next step of knowledge representation and reasoning (Q3478658), the future belongs to Wikidata. --Fractaler (talk) 15:53, 10 February 2017 (UTC)

Good points -- wikidata items shouldn't necessarily be defined by what's in a wikipedia article. But I'm not sure what to do if the "wrong" wikipedia articles (perhaps in 30 different languages) are linked with this item, in that they contradict both the description and some of the existing existing statements about the item? Or what if a wikipedia article is equally about two items (but is linked with one of them) -- should there be a third item in this case so that one of them can link to the articles while being a superclass (or some other relationship) with the other two items? DavRosen (talk) 17:14, 10 February 2017 (UTC)

1) we can edit Wikipedia and then we can just refer to it - there, they say, look, as stated on Wikipedia! 2) Put authoritative links right here (it's faster, and time is money information). There is WikiProject Physics also (WikiProject Physics (Q8487193), Category:Science WikiProjects) Fractaler (talk) 18:05, 10 February 2017 (UTC)

Ah, I thought references in wikidata statements weren't supposed to just refer to wikipedia, but I guess the authoritative references should be in the wikipedia article anyway. Also do you know of an example of such a reference to a wikipedia article (or section?) in a statement so I can see which qualifiers are usually added and how it is referenced? DavRosen (talk) 15:38, 11 February 2017 (UTC)

I mean if we have page in WP we can create item here. Here we have "add reference". Place used to discuss any and all aspects of Wikidata - Wikidata project chat, Wikidata:WikiProject Physics --Fractaler (talk) 14:03, 13 February 2017 (UTC)