From: BillK (bill@wkidston.freeserve.co.uk)
Date: Tue Aug 12 2003 - 03:27:30 MDT
On Tue Aug 12, 2003 01:11 am Eliezer queried:
>
> What is the history of the measurement of the permittivity of free
> space, aka the vacuum permittivity or the electric constant, and the
> measurement of the permeability of free space, aka the vacuum
> permeability or the magnetic constant? In particular, what were the
> experimentally measured values of these constants in 1861 when
> Maxwell published his calculation of the speed of light from these two
> constants? I know that the estimate of the speed of light was
> Foucault's 1850 estimate of 298,000 > km/s. I can't find any
> historical account of these two constants at all, so I suspect I'm
> Googling under the wrong search terms.
>
One problem might be that they didn't have a system of units at that
time. The metric system was only officially adopted in 1795 in France,
electrical units were specified in 1861 in UK.
See: http://www.aticourses.com/international_system_units.htm
Alternatively, try:
http://www.what-is-the-speed-of-light.com/
for a history of trying to measure the speed of light.
Regards, BillK
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