N:dlzc D:aol T:com (dlzc) wrote:
Dear jem:
"jem" wrote in message
news
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N:dlzc D:aol T:com (dlzc) wrote:
Dear jem:
"jem" wrote in message
news:xUJhe.12379$sy6.6702@lakeread04...
...
"The true scientist must have faith and believe
in the scientific method of testing theories, and
not in the theories themselves.
It isn't a faith it is a dicipline.
It isn't a dicipline, it's a discipline. 
Good post, but does a relativist take the position
that "absolute quantities cannot be defined"?
Doesn't any invariant quantity qualify as an
absolute quantity?
c is an invariant quantity. It is however not
absolute to all frames, for all paths that light
can take. Only to local frames is it invariant.
Alpha serves to similarly tie down the other big "invariant
quantities".
Sorry David, but I'm not getting your point.
Depending on the measurement details, the
speed of light in Relativity can be invariant or not.
Sounds like it is not a good candidate for "absolute". If I know
the distance, and measure the time-of-flight, then get something
less than c (for light travelling in a vacuum), would I consider
that quantity "absolute"?
If it is (e.g. measured locally, in vacuum),
then that speed presumably could be
considered an "absolute quantity". No?
*I* wouldn't consider it absolute, no. How do you want to define
absolute?
Here is how the dictionary has it:
ADJECTIVE:
1) Perfect in quality or nature; complete.
2) Not mixed; pure. See Synonyms at pure.
3a) Not limited by restrictions or exceptions; unconditional:
absolute trust.
3b) Unqualified in extent or degree; total: absolute silence. See
Usage Note at infinite.
4) Unconstrained by constitutional or other provisions: an
absolute ruler.
5) Not to be doubted or questioned; positive: absolute proof.
6) Grammar
6a) Of, relating to, or being a word, phrase, or construction
that is isolated syntactically from the rest of a sentence, as
the referee having finally arrived in The referee having finally
arrived, the game began.
6b) Of, relating to, or being a transitive verb when its object
is implied but not stated. For example, inspires in We have a
teacher who inspires is an absolute verb.
6c) Of, relating to, or being an adjective or pronoun that stands
alone when the noun it modifies is being implied but not stated.
For example, in Theirs were the best, theirs is an absolute
pronoun and best is an absolute adjective.
7) Physics
7a) Relating to measurements or units of measurement derived from
fundamental units of length, mass, and time.
7b) Relating to absolute temperature.
8) Law Complete and unconditional; final.
It meets 7a (since it defines the length measurement, but fails
the rest. "Unconstrained by ... other provisions". Such as "only
when locally measured", or "only when there isn't a massive body
near the flight path".
I used the example of light because you did, but in order to measure
something the measurement procedure has to be specified (e.g. locally,
in vacuum), otherwise if any old measurement procedure would do, the
quantification would be meaningless.
OK you don't like using light, then use any quantity at all that you
think is invariant, and indicate why "absolute quantity" is an
inappropriate characterization.