IAU thesaurus in RDF (an update)

[Frederic V. Hessman]

> 	I suggest that the vocabulary contains only singular terms.  Right  
> now it is inconsistent on this.  All of the star things are _stars,  
> but many terms are singular like abundance, Alven_surface, age.
> Perhaps there was some initial idea of having singular subject  
> headings
> and plural object classes, but this gets very muddy fast.  I don't  
> see any real benefit in plural over singular, it is just an extra  
> character or two.

This is what we used in the SV proposal, thinking that singular was  
simpler.   I don't know what Shobbrook^2 were thinking about: maybe  
plural was intended to indicate some sense of generality.  Their  
usage suggests that abstract concepts were kept singular (e.g.  
"convections" doesn't make any sense) but things which are  
instantiable were made plural (e.g. "convective flows").  It wouldn't  
be too hard to convert everything to singular, but....

> #Stars only has bright_stars and Sun as narrower.  There should be  
> much
> more.

Wasn't me!

> "#Kelvin related temperature_scale", but it is a temperature_scale.
> More exactly, it is an absolute_temperature_scale which is a
> temperature_scale.
> Hey, there is no Fahrenheit at all.  Was this an intentional slight?

You're right.  We also forgot furlongs, stones, bushels, fluid  
ounces, pecks, miles, nautical miles, knots, ....

> "#terrestrial_radiation narrower atmospheric_radiation", but one now
> sees atmospheric radiation on Jupiter etc, so I would say the relation
> is reversed.
>
> "#turbulence_Earth_atmosphere narrower microturbulence" and
> "#turbulence_Earth_atmosphere narrower macroturbulence".
> Not really.
>
> "emission_line_star narrower shell_star".
> Not really.  Shell stars have absorption lines from a shell of gas.
> They could have emission lines as well, but that is not in the  
> definition.

I'm only responsible for a zillionth of the BT's, NT's, and RT's, so  
don't blame me for most of this.

I'm frankly not very interested in the ontological info just yet (I'm  
still trying to check for the right tokens), but I'll be happy to  
correct any concrete example submitted by anyone as long as you  
indicate 1) the present entry; and 2) proposed corrected entry, and  
not just one BT/NT/RT at a time!

Too bad we can't get the list onto a good Wiki site..... (hint, hint,  
hint): I'm happy to do more than my share of editorial work, but if  
ya'll start to mess with the ontological info, the job will get  
gigantic.  The present goal should be to remove egregious errors only.

> Someone asked if there needs to be Individuals.  This already has Sun,
> Moon, Earth, Mars and others.  It turns out that there are a few  
> that are needed because other terms are so related to them.   
> Although one
> probably could substitute #spicules skos:related #stars for #spicules
> skos:related #Sun, etc.  But, maybe we should have both.  But it is  
> clear that one should have at least a few Individuals.

Absolutely.  The original IAU thesaurus just had the Sun and the  
Milky Way, not even the Solar System planets.  For lack of time, I  
only went as far as Pluto & Ceres, Moon, and Solar System.

> Talking about individuals.  There is a #velocity_of_light.  Do we need
> velocity_of_light_in_vacuum to distinguish from in_medium?

Good question.   My gut response is no, thinking that the speed will  
be appropriately derivable from the situation, but I might be wrong.   
Do we then need "frequency_in_a_medium"?  Ugh!

> infrared_radiation should have broader electromagnetic_radiation, as
> ultraviolet_radiation has.

Indeed.  In fact, although I have been through the SV tokens on the  
search for missing things, someone should go through the UCD list and  
do the same:  the final official IAU list should at least be able to  
cover the UCD concepts.

> Is infrared_radiation synonymous with infrared_emission?

A good example of how Shobbrook^2 put in more casual terms which  
librarians might encounter in astronomical texts but without any  
formal physical need.  On the other hand, "infrared_emission" implies  
not only "infrared_radiation" but also some source, and we don't yet  
have a standardized means of combining tokens.   In any case, for  
pure reasons of compatibility,  we should keep the original IAU list  
at least in the form of ALT's if they make any sense whatever.

> I don't see a way for SKOS to say SameAs.  How does one say  
> iau:stars sameas cds:stars?

A question for the pundits, not me :-)

Rick

------------------------------------------------------------------------ 
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Dr. Frederic V. Hessman     Hessman at Astro.physik.Uni-Goettingen.DE
Institut für Astrophysik          Tel.  +49-551-39-5052
Friedrich-Hund-Platz 1         Fax +49-551-39-5043
37077 Goettingen                 Room F04-133
http://www.Astro.physik.Uni-Goettingen.de/~hessman
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MONET: a MOnitoring NEtwork of Telescopes
http://monet.Uni-Goettingen.de
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