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I Poynting energy flow in Eath's atmosphere?

  1. Jul 21, 2016 #1
    Poynting new.jpg
    1.There is an electric field between ionosphere and ground, also earth's magnetic field is perpendicular to this E field, hence by poynting theorem integrating E x H across the entire surface of earth gives a great deal of energy flowing west to east.
    2. |S| = (E X B)/u0 = (150 V/m X 0.045 T)/(1.25 X10^-6 H/m) = 54,00,000 W/m^2 !!!!!
    3. Imagine keeping a copper rod along west-east, will there be a emf induced across the rod's ends ?, i think we can't measure this voltage because even the voltmeter is inside such an energy flow viz., there is no "sink" or "ground" to do the measurements
    4.Are earth currents because of soil intercepting this flow partially? all your opinions are welcomed. .
     
  2. jcsd
  3. Jul 21, 2016 #2
    Just because a volume of space contains E and H fields in a certain configuration, not sure that it necessarily means there is a flow of power. I suspect these fields can either be caused by a flow of power or can have a separate existence not caused by the flow of power. As an example, suppose I fix a magnet to a Van de Graaff machine. Is there then a flow of power under steady conditions?
     
  4. Jul 21, 2016 #3

    Dale

    Staff: Mentor

    Yes. There are closed loops of energy flowing around such a configuration. While the fields are maintained constant there is no work done on matter and no change in the field energy density. All of the energy flowing into a region also flows out.

    Just as importantly this type of field configuration has angular momentum. Under the right conditions the field can be reduced to recover the energy and angular momentum.
     
  5. Jul 21, 2016 #4
    Mr Dale i want some more links on Heaviside Component.
    I didn't find one except his own papers which are difficult to understand ...if you have one please share it with me
     
  6. Jul 21, 2016 #5

    Dale

    Staff: Mentor

    I have never heard of heaviside Component
     
  7. Jul 22, 2016 #6
    Thank you, Dale. And I am supposing that when the V de G machine is switched on, whilst it builds up, an EM wave will be set up which feeds or builds the closed loops of energy. And at switch off, another EM wave is created which extracts that same energy. Similarly if the magnet is an electro magnet and is turned on and off.
    As this EM wave is of a very low frequency, I am supposing that it is captive and not radiated.
    I am very interested that a captive EM wave having a frequency of a fraction of a Hertz might be part of everyday electrical phenomena.
     
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