Re: The history of the vacuum permittivity and permeability

From: BillK (bill@wkidston.freeserve.co.uk)
Date: Tue Aug 12 2003 - 03:27:30 MDT

  • Next message: Eliezer S. Yudkowsky: "Re: The history of the vacuum permittivity and permeability"

    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

    __________________________________________________________________________
    Join Freeserve http://www.freeserve.com/time/

    Winner of the 2003 Internet Service Providers' Association awards for Best Unmetered ISP and Best Consumer Application.



    This archive was generated by hypermail 2.1.5 : Tue Aug 12 2003 - 03:36:49 MDT