From: jos.bergervoet@xs4all.nl   
      
   On 2/28/2017 9:02 AM, John Heath wrote:   
      
   >  .. Not just a magnet but a copper wire   
   > carrying 10 amps should also have effective   
   > electron contraction leading to an extreme   
   > negative voltage around the wire.   
      
   Why do you believe that? Even if the electrons   
   were contracted as flat as pancakes (imagining   
   them as particles) they will still keep the same   
   distance towards each other, hence leaving you   
   with the same original average charge density.   
   Remember the Lorentz transform is *not only*   
   time contraction but also time-space coordinate   
   mixing so it changes the time schedule in which   
   they are passing by in two ways, together giving   
   no change.   
      
     ...   
   > One more. Sky charge. Sky charge is about   
   > 100 volts per meter or 200 volts from head to   
   > toe. Like the Lorentz electron contraction   
   > this is a voltage that can not be measured   
   > with a conventional meter. The solution is a   
   > voltage field meter. It consist of a fan ,   
   > sheet of copper and a hole on top. If there   
   > is a fluctuating voltage at the copper plate   
   > that equals the frequency of the fan blades   
   > than there is an electric field. Maybe this   
   > would work?   
      
   What works is to use an oscilloscope, connect some   
   piece of wire (or a metal plate) to the probe tip   
   and then swing it around by the cable. You will   
   see a sine wave (in the order of 2Hz if you swing   
   cautiously). Looking at the scope and at the same   
   time swinging the cable without hitting your legs   
   is the only tricky part. And it only works outdoors,   
   as there isn't a big static E-field inside the house.   
      
   I got about 1 volt sine wave on the screen on a   
   normal day (no imminent thunderstorm) which is of   
   course divided by the plate's capacitance to   
   surroundings (in the order of 10 pF) and the input   
   impedance of the probe (a few pF parallel to 20   
   MOhm or similar..) and then again divided by the   
   sensitivity of the probe (like 1:10 or 1:100).   
      
   --   
   Jos   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)