virus: Re : Quantum TT / The Speed of Light

Hakeeb A. Nandalal (nanco@trinidad.net)
Fri, 15 Nov 1996 05:44:33 +0000


Schneider John wrote:-

> ........
> That's not quite how it works: the uncertainty principle relates
> pairs of observables. Even though knowledge of both speed and
> location is subject to the uncertainty principle, it is still
> the case that the speed of a photon may be determined with
> arbitrarily small uncertainty (in theory).
> ........

The Speed of Light is a constant depending on who's doing the measuring :-

Taken from "Electromagnetic Distant Measurement" by C.D. Burnside
(no URL, I actually got it from a real book)

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Person Date Velocity (km/s) Method
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Romer 1676 214000 Eclipses of Jupiter satellites

Bradley 1726 301000 Aberration of stars

Fizeau 1849 313000 Terrestial, wheel modulation

Rusa & Dorsey 1906 299784 +/- 10 Ratio of electromagnetic to electrostatic units

Michelson 1927 299796 +/- 15 Rotating Mirror device

Michelson & ors. 1933 299774 +/- 04 Rotating Mirror, mile long tube

Anderson 1940 299776 +/- 06 Kerr cell device

Birge 1941 299776 +/- 04 Weighted mean of past results

Essen & ors. 1947 299792 +/- 04 Cavity resonators

Aslakson 1949 299792 +/- 02.4 Radar measurements

Aslakson 1951 299794.2 +/- 02.4 Radar measurements

Bergstrand 1949 299793 +/- 02 Kerr cell - Geodimeter device

Bergstrand 1951 299793.1 +/- 00.2 Kerr cell - Geodimeter device

Essen 1950 299792.5 +/- 01 Cavity resonators

Froom 1954 299792.7 +/- 00.3 Microwave interferences

Scholdstrom 1955 299792.4 +/- 00.4 Kerr cell device

Ordnance Survey 1956 299792.4 +/- 00.5 Geodimeter 4, Ridgeway base

Froom 1957 299792.5 +/- 00.10 Microwave interferometer

................................................................................................

Accepted value 1973 299792.485 +/- 1.2 km/s

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Apparently that "arbitrarily small uncertainty" is 1.2 km/s.

As far as I know the 1973 value hasn't been updated.

---------------------------------
Hakeeb A. Nandalal
nanco@trinidad.net
"Divine intervention is unlikely"
- The Doctor, ST Voyager
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