What use the AstroOntology
eshaya at umd.edu
Tue Mar 6 09:25:33 PST 2007
> My personal view is that static ontologies are likely to be
> of limited usefulness in a field where concepts are ill-defined, in a
> constant state of flux, and are often subjective.
Ontology would be frustrating in a field that changed completely from
year to year. But astronomy does not. Go through any list of
astronomical terms and ask for each and every one, has the definition of
this term changed in 10 years. Really do it, and you will see that less
than 1 in 100 have changed significantly. There are perhaps 3 or 4 new
terms each year. We tend to be focused on the hot topics because there
is controversy but astronomy is full of ancient terms. Even the issues
"at the frontier", like QSO is not really fluctuating. The discussion
we had over whether it is or is not a subclass of AGN would have been
almost exactly the same 30 years ago. Dark matter is 50 years old, Dark
energy is new, but that means 5-10 years, and anyway it is very nearly
an alias to Cosmological Constant which is 80 years old,
>I question the
> assumption that knowledge in astronomy is made out of atomic facts.
There are many complex ideas in astronomy. But complex ideas can be
expressed as a set of simple statements linked together. We would not
be able to communicate otherwise.
> I don't think the maintainability problems will go away by liberal
> sprinkling of aliases or probablistic 'might-be-a' relationships. As an
> earlier poster pointed out, the strength of ontological reasoning is
> derived entirely from the rigourousness and precision of the concepts
> defined. Sacrifice that, and all queries will return the equivalent of
> 'here's some things you might be interested in' - which is where we
> already are.
Well, we are close enough now that it is worth it to continue to try and
find out. If you are right we will completely fail at creating any
useful applications. I happen to think that humans are not at all
rigorous or precise and yet we manage somehow. A formalized ontology,
even if not complete and precise, is likely to bring about greater
preciseness into our terminology in the long run.
> It's not my intention to be negative or confrontational. I appreciate
> that these are works in progress, people are committed to different
> approaches etc. It's likely there excellent counter-arguments to the
> issues I've raised. I think they should be made explicit. A bit of
> clarity would certainly help me understand the viewpoints others here hold!
> Eric Saunders
> eSTAR Project (http://www.estar.org.uk)
> Astrophysics Group
> University of Exeter
> On Mon, 5 Mar 2007, Ashish Mahabal wrote:
>> This is getting very Godelsk.
>> The aliasing mechanism provides for consistency. We could thereby miss
>> some truths. We can only hope that we do not miss any interesting ones.
>> Flikr, blogspot are inconsistent systems in that A would define SN as
>> something and B would define SNe as something else, but C may presume
>> them to be the same. All will be happy, but at least one will be wrong.
>> Ashish Mahabal, Caltech Astronomy, Pasadena, CA 91125
>> http://www.astro.caltech.edu/~aam aam at astro.caltech.edu
>> Gods do not protect fools. Fools are protected by more capable fools.
>> -Luis in Larry Niven's Ringworld
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 257 bytes
Desc: not available
More information about the semantics