Sorry that I did not find the time to reply earlier. (01)
> -----Oorspronkelijk bericht-----
> Van: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
>[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] Namens
> doug foxvog
> Verzonden: woensdag 26 september 2012 19:50
> Aan: [ontolog-forum]
> Onderwerp: Re: [ontolog-forum] Universal Basic Semantic Structures
>
> On Wed, September 26, 2012 11:44, Andries van Renssen wrote:
> > John F Sowa on 26 september 2012 at 15:53 wrote:
> >> On 9/26/2012 8:53 AM, Andries van Renssen wrote:
> >> ...
> >> > But the piece of land that is defined by that boundary is
> >> > nevertheless a physical object, and it has a mass, although
> >> > its value is unknown and not of interest.
>
> >> Space is physical, but it doesn't have a mass. An area is
> >> a two-dimensional region. The political subdivisions only
> >> specify coordinates that determine the area at the surface,
> >> and they are silent about depth or height.
>
> > [AvR] I hesitate about the mass of a physical space, and whether the gas
> > in a space is part of the space or just occupies the space.
>
> Occupies.
[AvR] Why? In geometry we make a distinction between a hollow sphere and a
solid sphere.
By excluding the content of a space from the definition of the space you seem
to define a physical space as a hollow space, whereas
I think that the analogy is more with the solid space, including the content.
>
> > But if the space is
> > not empty, the mass may be of interest such as in the interior of a
> > balloon and a submarine.
>
> Sure.
>
> > ...
> > I question whether a physical area is by definition two dimensional.
>
> I'm not sure what you mean by "physical area".
[AvR] See below.
>
> > Mathematical area's are two dimensional. But two dimensional area's in
> > physical reality seem to be abstractions. They are at least curved in the
> > third dimension.
>
> Fine. Math allows this. Iit also defines planar 2D areas.
[AvR] Which implies that two dimensional area's (which are abstract) do not
belong to the physical domain, but to the mathematical
domain.
>
> > But more important: if you walk on them, they compress
> > under pressure and they provide an upward force on you.
>
> The areas don't compress. The physical surface does.
[AvR] In my view a (physical) surface is a kind of (physical) area. If a
surface compresses, that implies that the area compresses.
>
> > If you buy them
>
> You don't buy an area (or volume). You buy physical land or part of
> a physical structure or rights to take certain actions within some
> volume (spatial or physical).
[AvR] I don't understand what is wrong with the statement to buy an area. I
make a distinction between two homonyms: (physical) area
as a physical object with a shape and (property) area as an aspect (e.g. of a
physical area), measured as a two dimensional integral
of distance. I discussed the first concept. You seem to argue on the basis of
the second concept.
My impression is that you do not make the distinction.
>
> > then you also possess a mass with volume below and a space above it,
>
> If you buy a physical object, then you own (a social property) the mass
> that comprises that object along with associated rights as defined by
> society.
>
> > although constrained nowadays by government rules.
>
> and before that by societal rules.
>
> > Although they are typically
> > defined in two dimensions only, their third dimension is recognized and
> > constrained by government rules (as you describe below).
>
> It appears that you are referring to plots of land here, not "two
> dimensional area's in physical reality".
>
> > This is related to the concept of 'surface'. A surface can have a
> > roughness,
> > a color, a hardness, a temperature, a strength, etc. I think that it can't
> > have such properties when it would be only two dimensional.
>
> One could certainly define such, e.g., the lat/long of its centroid.
>
> > We are probably
> > influenced by the abstract mathematical concept of dimensions.
> > In practical physics, every physical point has a size that is non zero,
> > although nearly infinitesimal.
>
> What do you mean by "physical point"?
[AvR] With "physical point" I means a volume of negligible small size, but not
of zero size. Because things of zero size cannot be
observed nor located and therefore do not belong to the physical domain.
However, mathematical points with zero size do exist in the
mathematical domain.
>
> >> By fiat, the governments of countries lay claim to the mineral
> >> rights beneath their areas. In principle, they could claim rights
> >> down to the center of the earth. But in practice, the technology
> >> can only mine a few km. beneath the surface.
>
> >> When air travel became possible, national governments laid claim
> >> to the air space above them, but smaller governments did not.
> >> But nobody laid claim to the regions above the atmosphere.
> >> Those are more distinctions by fiat.
>
> >> In summary, I recommend that any ontology for any subdivision
> >> of the earth should specify the surface area S and the intended
> >> role R for that area.
>
> > [AvR] In some cases (e.g. mines, reservoirs) the subdivision of the earth
> > requires an explicit third dimension.
>
> Agreed.
>
> > And some, such as lakes and mountains, don't need a role.
>
> Huh? Wouldn't a lake/mountain have the roles of being part of some
> enitity's territory and some (other) entity's property?
[AvR] They may have a role, but I stated that an ontology which includes such
concepts does not necessarily include their roles, as
(most of them) they are not created with an intended role, as artifacts usually
are.
>
> >> Then anything else that may be associated with the pair (S,R),
> >> such as the land, air, water, people, buildings, governments,
> >> should be specified as the X associated with the area S as
> >> considered in the role R.
>
> >> John
>
>
>
>
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