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Re: Isotropic Capacity

Subject:  Re: Isotropic Capacity
  Date:   Fri, 23 May 1997 09:30:41 -0500
  From:   David Huffman <huffman-at-FNAL.GOV>
    To:   Tesla List <tesla-at-pupman-dot-com>


Richard, All,
Are you saying that a tethered conductive balloon at say 30 meters
could have several thousands volts wrt ground, or do you need two
spheres at different heights? I'm guessing there is no practical way
to use this gradient to do any useful work, like say charge the
primary cap of a TC. The risk of having something hanging in the sky
that lightning could find has got to be a major drawback. :-(
Dave Huffman


----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-poodle.pupman-dot-com
> Subject: Re: Isotropic Capacity
> Date: Friday, May 23, 1997 1:20 AM
> 
> Subject: Re: Isotropic Capacity
>   Date:  Fri, 23 May 1997 01:10:40 -0400 (EDT)
>   From: richard hull <rhull-at-richmond.infi-dot-net>
>     To: Tesla List <tesla-at-pupman-dot-com>
> 
> 
> At 05:20 PM 5/21/97 -0500, you wrote:
> >Subject:  Re: Isotropic Capacity
> >  Date:   Wed, 21 May 1997 10:07:57 -0500
> >  From:   David Huffman <huffman-at-FNAL.GOV>
> >    To:   Tesla List <tesla-at-pupman-dot-com>
> >
> >
> >OK
> >The earth has an isotropic capacitance of about 712uF =
> >4*pi*e0*radius, so about how much charge? Is it measured by the
> >voltage difference between conductors at different elevations?
> 
> Dave,
> 
> The earth's atmosphere is charged as a separate item from the body
> itself.
> A two capacitor problem.  It is quite complex.  I have seen numbers
> bandied
> about but that is all I think they were.  The atmosphere is a
separate
> and
> dynamic system from the earth considered as a ball in space.  There
is a
> true and real atmospheric gradient with increasing altitude.  This
> gradient
> is highly variable with weather, humidity, pressure etc.  A catch
all
> phrase
> of 100 volts/meter is a tolerable average but deceptive.  I have
noted
> that
> until one really clears the ground by 5-10 meters, this average is
just
> not
> found.
> 
> Lots of neat experiments can be devised and tested with this
natural
> gradient.  This could begin by using some sort of ground based
> conductive
> tether, large lighter than air balloons with conductive skins.  In
the
> short
> haul with modest euipment, such work is at least risky and
hazardous. 
> In
> the extreme, the experiments could prove fatal.
> 
> Richard Hull, TCBOR
>