Ed, (01)
I agree with Ingvar that there is a fundamental difference between
time and temperature: There is a fundamental zero point for
temperature, but none for space or time. In that sense, temperature
should be compared to mass, which also has a fundamental 0. (02)
EB> The absolute zero of time is presumably the Big Bang... (03)
As far as we know, there are no physical laws that depend on
the time interval between now and the Big Bang. The time of
the Big Bang was estimated on the basis of laws that have no
fundamental dependence on a zero point for time. (04)
But there are many laws that depend on a zero point for temperature:
For a gas, pressure times volume is proportional to temperature,
as measured from absolute zero. (05)
Boltzmann's law states that the amount of energy radiated by an
object is proportional to T^4, also measured from absolute zero. (06)
The relevance for UoM is that 0 is fundamental for some units,
but arbitrary for others. (07)
John (08)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/uom-ontology-std/
Subscribe: mailto:uom-ontology-std-join@xxxxxxxxxxxxxxxx
Config/Unsubscribe: http://ontolog.cim3.net/mailman/listinfo/uom-ontology-std/
Shared Files: http://ontolog.cim3.net/file/work/UoM/
Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?UoM_Ontology_Standard (09)
|