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Re: [uom-ontology-std] retitled: magnitude of a quantity

To: uom-ontology-std <uom-ontology-std@xxxxxxxxxxxxxxxx>, John Graybeal <graybeal@xxxxxxxxx>
From: Pat Hayes <phayes@xxxxxxx>
Date: Sat, 18 Jul 2009 12:38:11 -0500
Message-id: <33E45E60-81D4-4F40-B816-9425717A2CBE@xxxxxxx>

On Jul 17, 2009, at 5:42 PM, John Graybeal wrote:    (01)

> On Jul 16, 2009, at 4:55 AM, Pat Hayes wrote:
>
>> It always bothered me that dimensional analysis made angles
>> dimensionless, when they are of such profound physical
>> significance.  Clearly, direction of length matters. The fact is,
>> 'length' should be treated as a vector rather than a scalar.
>
> Uh -- given a length of a stick, what's the origin of the coordinate
> system in the vector case?    (02)

I should have said, vector field.    (03)

> Don't you need both length and angle as
> independent things?    (04)

For actual analysis you do, but angles are dimensionless (in the usual  
notion of dimension.) so they 'vanish' when we consider dimensions.  
That is what bothers me. BUt it seems that others, more expert than I  
in this area, have already broken this ground.
>
>> This also, btw, helps with distinguishing length from width from
>> height. But this is probably going too far out in left field for
>> this forum :-)
>
> On ontolog? Seriously?    (05)

:-)    (06)

Pat    (07)

>
> I am eager to see the concrete steps under way.  This is a very
> interesting progression of work.
>
> John
>
> --------------
> John Graybeal   <mailto:graybeal@xxxxxxxxx>  -- 831-775-1956
> Monterey Bay Aquarium Research Institute
> Marine Metadata Interoperability Project: http://marinemetadata.org
>
>
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>    (08)

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