Tuesday, June 24, 2014

Age is not a quality

No matter how many times lazy ontologists represent age as a quality of a human, organism, or other material (or immaterial I suppose) entities, it just isn't true.  Age is not a quality.

An age is a measurement of elapsed time since a particular entity came into being.  Typically, it is the measurement of elapsed time in the frame of reference of the entity itself.  For example, muons have a lifetime of 2.2 microseconds as measured from the frame of reference of the muon itself.  However, as measured from the frame of reference of the surface of the Earth, the muons entering the atmosphere have a mean lifetime of approximately 18.5 microseconds.

Therefore, age should be a type of measurement in ontologies.

We also note that age is always with respect to the time the measurement is made.  For example, if John Doe was born on Jan 1, 1970 UTC, then if we measure his age on Jan 2, 1970 UTC, we will obtain that John is 24 hours old.  But if we measure his age on Jan 1, 1971, we will obtain that he is 365*24 =8,760 hours old (1970 not being a leap year).

So an age measurement should always be accompanied by an appropriate measurement date/time.