Re: Our 'humiliating' mistakes.

[brian whatcott <inet@intellisys.net>]

At 10:16 9/13/97 -0700, Ludwik (?) wrote:
> > P.P.S. Oh, I remember something else:   The entire earth is only a few
> > farads, isn't it?
>
> The capacitance of a conducting sphere (against the sphere at infinity)
> is equal to its radius. The radius of Earth is about 6378 km which is
> about 0.6 farad, since one cm is about one pF.
>
> Leigh
I can see that Leigh is quite determined to be a living example of
not being humiliated by petty mistakes, so I mention...

1) Though the equatorial diameter is given as 6378 km, on this
 oblate spheroid with a polar diameter of 6357 km, the mean radius 
is better given as 6368 km.

2) If 1 cm. (1E-2 m.) of radius represents 1pF   
     then
   6.378E6 m. represents    6.378E6/1E-2 pF = 6.378E8 pF or 6.4E2 uF

This value of 640 microfarad is not what Leigh had in mind.

Regards
p.s. Never saw the beginning of this thread....
brian whatcott <inet@intellisys.net>
Altus OK