Wikidata:Property proposal/attenuation coefficient

attenuation coefficient

Originally proposed at Wikidata:Property proposal/Natural science

Done: attenuation coefficient (P5992) (Talk and documentation)

Description	Characterizes how easily a volume of a material can be penetrated by a beam of light, sound, particles, or other energy or matter. Beam type is to be secified using P1013.
Represents	attenuation coefficient (Q902086)
Data type	Quantity
Template parameter	This proprety request is part of the project of creating an infobox for materials.
Domain	material (Q214609)
Allowed values	Any number. transmitted signal type (P1170) is a mandatory qualifier. Others qualifiers : wavelength (P2808), frequency (P2144), temperature (P2076), under pressure (P2077)...
Allowed units	reciprocal length (Q1028259) units such as reciprocal metre (Q11547251)
Example 1	Cleartran (Q57306213) → 0,00000006 reciprocal metre (Q11547251) at wavelength (P2808) → 1.3 micrometre (Q175821) for transmitted signal type (P1170) → light (Q9128)
Example 2	CVF-1-2754 convoluted acoustical foam (Q57306286) → 0.94 reciprocal metre (Q11547251) at frequency (P2144) → 2000 hertz (Q39369) for transmitted signal type (P1170) → sound (Q491713)
Example 3	lead (Q708) → 0.000521 square centimetre per gram (Q57306331) at photon energy (Q25303639) → 1000 electronvolt (Q83327) for transmitted signal type (P1170) → X-ray (Q34777) [1]
Source	w:Attenuation coefficient
Planned use	Creating an infobox for materials

Motivation

Usefull data for material selection in optics, electromagnetism, sound protections... --Thibdx (talk) 23:08, 13 October 2018 (UTC)[reply]

Discussion

Support David (talk) 07:52, 14 October 2018 (UTC)[reply]
Support seems useful - however I'm not sure on the use of criterion used (P1013) to specify the thing being attenuated, have you considered other qualifiers for this? ArthurPSmith (talk) 14:18, 15 October 2018 (UTC)[reply]
- I would agree. I found it hard to find something relevant in existing properties. Maybe has cause (P828) or source of energy (P618) ? --Thibdx (talk) 22:46, 15 October 2018 (UTC)[reply]
  - @Thibdx: I think transmitted signal type (P1170) has the right sort of name, but it's currently a rather restricted domain. Unless there's something better I'd suggest we query at that property about slightly expanding its scope? ArthurPSmith (talk) 17:56, 16 October 2018 (UTC)[reply]
    - Nice ! I had not seen this one. How can we query for expanding its scope ? --Thibdx (talk) 20:28, 16 October 2018 (UTC)[reply]
There is no qualifier for 'photon energy', as presented in example 3, and I don't think we have any qualifier for this in WD yet. Maybe we could just create some generic qualifiers like 'energy' and one for type of energy (or maybe use Wikidata:Property proposal/environment? or source of energy (P618)? for the latter). Wostr (talk) 20:55, 16 October 2018 (UTC)[reply]

It seems: that w:Photon energy is proportional to its frequency (P2144) and inversely proportional to its wavelength (P2808). Anyway, I see different options :

We could generalise into particle energy (details on w:Energy–momentum relation). The physics projects may be interested.
Energy and Type of energy would be usefull. There is some existing energy properties : binding energy (P2154), ionization energy (P2260), luminosity (P2060) but the list is far from complete.
- The pro : it would not be necessary to create a property of each type of energy : cinetic, potential, thermal... (w:Energy#Forms)
- The cons : this type of wide property that can be used many ways don't displays nicely in Wikipedia infoboxes. As far as I understand you need to display the full qualifiers list. There is also the risk of redundancy with existing properties. If the different items use different systems the data will not be usable.

This point must not be blocking the attenuation coefficient property creation because it is very specific to a sort of beam and can be switched to frequency (P2144) and wavelength (P2808). It is still a very intersting point that have to be discussed in the Physics project.

--Thibdx (talk) 21:44, 16 October 2018 (UTC)[reply]

@Thibdx, ديفيد عادل وهبة خليل 2, Wostr, ArthurPSmith: Done: attenuation coefficient (P5992). − Pintoch (talk) 19:26, 24 October 2018 (UTC)[reply]