some remarks on VOEvent

[Ed Shaya]

In thinking about how to mesh VOEvent with the science ontology, it 
appears that VOEvent is a kind of Publication.  Perhaps under Report.  
This is where IAU_Circular would also go.  Publications would have 
hasDescription and that would have subProperty hasExplanation.  The 
range of hasExplanation would include Explanation, Hypothesis, Theory, 
Postulate, Fact and Axiom where:
VOEvent would take Hypothesis and Theory
Hypothesis - One of several possible  testable explanations
Theory - Only known explanation  that  fits the  observed  data.

Hypothesis and Theory could in turn have hasExplanation of:
Postulate - statements of assumptions needed to continue the line of 
reasoning.
Axiom - a truth commonly accepted and in no need of proof.
Fact -  Real world facts (New York is in the US) and Mathematically or 
logically proven statements.

The VOEvent is different from  ast:Event because an instance of an 
ast:Event is the event itself not claims about the event.   However, 
times, locations and measurements of the event do belong in ast:Event. 
Once there is a theory of the event it can be subclassed to the specific 
type of event that it is (ast:supernova etc).

Ed