Re: The speed of light

John Clark (
Mon, 19 Jul 1999 16:58:18 -0400

Hash: SHA1

Ron Kean <> Wrote:

>According to the CRC Handbook of Chemistry and Physics, the second is the
>duration of 9,192,631,770 periods of the radiation corresponding to the
>transition between the two hyperfine levels of the ground state of the
>atom of Cesium 133.

Ok, but how long is a meter? If you define it as 1/299782458 of the distance light moves in one second that means that as your experimental procedures improve and you know the exact speed of light better the length of a meter changes.

You can't define everything as you wish and remain consistent. In the last century the Indiana state legislature tried to pass a law decreeing that the exact value of PI was 4. It missed becoming law by one vote, but probably wouldn't have worked anyway.

John K Clark
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