Talk:Q3198
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Autodescription — photon (Q3198)
description: elementary particle, the carrier and quantum of electromagnetism
- Useful links:
- View it! – Images depicting the item on Commons
- Report on constraint conformation of “photon” claims and statements. Constraints report for items data
For help about classification, see Wikidata:Classification.
- Parent classes (classes of items which contain this one item)
- photon (Q3198)
- gauge boson (Q105580)
- stable elementary particle (Q21660975)
- real neutral particle (Q4204340)
- Q15809444
- massless quantum particle (Q2024141)
- →(⁋) force carrier (Q24364)
- →(¶) quantum (Q46344)
- →(@) elementary particle (Q43116)
- photon (Q3198)
- Subclasses (classes which contain special kinds of items of this class)
- ⟨
photon⟩ on wikidata tree visualisation (external tool)(depth=1) - Generic queries for classes
- See also
- This documentation is generated using
{{Item documentation}}.
Counting unit[edit]
Hello @Ladsgroup: I notice that you removed the statement that a photon is a counting unit. Currently this item has statements involving Wolfram Language unit code (P7007) and measured physical quantity (P111) which are now flagged as constraint violations. Toni 001 (talk) 08:09, 22 September 2020 (UTC)
- User:Toni 001. Hey, I'm sorry but photon is everything but a measuring unit (I have studied physics in university). Please add an exception to the constraint or ignore it. Amir (talk) 15:49, 23 September 2020 (UTC)
- @Ladsgroup: Hi, thanks for your suggestion. Though, after having worked hard for over a year on quantities and units in Wikidata, I'd rather not simply silence the constraint violations but rather understand the nature of the issue so that it can be properly handled.
- About counting units in particular: This is a tricky case. Typically, when there is a "counting quantity", the unit would be 1 (Q199). However, some authors prefer to indicate in the unit, as in "apple count = 3 apples". To my knowledge, there is no consensus in the literature, the standards (SI, ISO/IEC 80000) and unit ontologies on how to handle such cases. Some argue against "giving names to the unit 1", some suggest parametric quantities/units and some explicitly introduce them . For Wikidata, I've so far taken the pragmatic approach of classifying objects as counting unit (Q78754808) if any notable unit ontology (of which there are about 5) goes to the trouble of defining one.
- Now the question is, in a statement like "photon count = 3 photons", does "photons" refer to this item (Q3198) or something else, conceptually.
- Best wishes. Toni 001 (talk) 09:50, 24 September 2020 (UTC)
- User:Toni 001 I don't think that's true, if what you suggest would be implemented, we basically need to mark half of the items as counting unit. Apples, trees, humans, papers, electrons, cars, camels,... I highly recommand bringing this up in a larger discussion, like WD:PC Amir (talk) 10:36, 26 September 2020 (UTC)