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Re: Metric Time (was Re: Why not 13 months? (Was La Systeme Metrique))
jrhodes@pupgg.princeton.edu
10 Oct 1995 22:44:03 GMT
In article <813358833snz@foxhouse.demon.co.uk>, Fred Read <Fred@foxhouse.demon.co.uk> writes:
>
>Sorry Jason, but you are wrong and Wouter is right.
>
>It is correct to say that the [circumference of the earth, the
>speed of light, the atomic weight of Uranium] is KNOWN very
>precisely because these are measurable quantities.
>
>The metre, however, is a contrived unit of length - an abstract
>concept, which is DEFININED very, very precisely. You may 'know
>the metre to a very high precision', but that knowledge is the
>definition...
>--
>Fred Read
>How many people do *you* know with a C function named after them ?
I mwill say it again- read ANY introductory physics text. But
you have to get one writtne since 1983, when the convention was
changed. The speed of light is DEFINED. The meter is what is
measured. If you don't believe the physics texts, try reading
part 2 of the August issue of Physics Today (1994 or 1995!).
This is the buyers guide issue and it has the latest on the
physical constants in it. Check out the uncertainty of the speed
of light. It is zero, because it is defined. I can't spell it
out any clearer for you. Fred and Wouter, you are the ones that
are wrong. I have provided you with sources for my argument. If
you still don't agree you had better take the gripe up with the
people publishing the textbooks and Physics Today and the people
that are deciding how we do measuring.
One more time--- the meter is a measured quantity. Got it?
Jason
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