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Natural electrical circuits?

  1. Jan 8, 2016 #1
    Hello everyone, I have a strange question. Can complete electrical circuits be found in nature? If so, can you give any examples? And what is necessarily required (besides electricity) for a complete electrical circuit to occur, naturally or unnaturally?
     
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  3. Jan 8, 2016 #2

    anorlunda

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    How about the nervous system in your own body?
     
  4. Jan 8, 2016 #3
    Right sorry, I also mean found in non living matter. Like rocks, or water, or wood.
     
  5. Jan 8, 2016 #4

    anorlunda

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    How about galvanic corrosion?

    I'm sure there are dozens and dozens of examples.
     
  6. Jan 9, 2016 #5

    jim hardy

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    What about lightning ?
    Charge is carried aloft , returns to earth
    Kirchoff seems to be okay with the time delay.
    Or you could think of it as a capacitance phenomenon...
     
  7. Jan 9, 2016 #6

    meBigGuy

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    My random thoughts:
    There is electrical energy flowing whenever there are electrically connected dissimilar metals in an electrolyte. Happens in seawater a lot. Or, even in the ground (like oil and gas pipelines).
    Static electrictity charge accumulation and discharge is common, the most dramatic being lightning. Static electricity accumulates and dissipates routinely on all sorts of surfaces.
    The northern lights are electrical phenomena due to solar storms.
    Solar storms create induced currents in all sorts of things (power lines, pipelines, anything that conducts).
    Anytime a piece of metal moves in the earth's magnetic field there are induced currents.
    Electric fish are a dramatic living example.

    Two major sources:
    Any place a charge can accumulate and dissipate from natural causes, either chemical or physical, you have, by definition, a complete circuit.
    Any conductor moving in a magnetic field or conductor in a changing magnetic field.
     
  8. Jan 9, 2016 #7
    I know there are plenty of examples for natural electrical currents, but is something like lightning a complete electrical circuit? Such as those found in computers and nervous systems?
     
  9. Jan 9, 2016 #8

    anorlunda

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    The important thing you should know is thst charge is conserved. It does not just appear or disappear.

    If lightning was not part of a complete circuit it would leave a big pile of plus charges someplace and another pile of minus charges another place. Since we don't find charged places like that on this planet, the circuit must be closed, no matter how indirectly. Does that make sense to you?

    The actual ways those charges migrate to meet up eventually may be hard to identify. But the fact that ereryplace is approximately neutral is the evidence that it must happen.
     
  10. Jan 9, 2016 #9

    meBigGuy

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    Lightning IS the completion of the circuit. Charges build up in the clouds and then discharge as a lightning bolt or other plasma effects. Current flows, that's a circuit. There are probably simulation models that describe the lightning circuit in gross detail (I've never looked --- maybe you can).
     
  11. Jan 10, 2016 #10

    anorlunda

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    Unipolar?

    Considering only cloud-earth lightning:
    If the initial and final conditions are neutral clouds and neutral earth, and if the lightning stroke transports charge, then it follows that there must be an additional flow of charge from-cloud-to earth either pre or post strike to make everything balance. We don't need any models at all to know that the time integral of cloud-earth charge migration must be zero.
     
  12. Jan 10, 2016 #11

    jim hardy

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    i've long felt it's got to have something to do with evaporation of the water that makes thunderclouds

    upload_2016-1-10_7-29-58.png


    ^^ looks to me like a mechanism for charge transport

    upload_2016-1-10_7-34-44.png
    Fridman & Kennedy, Plasma Physics and Engineering

    Might that orientation 'positive inward negative outward' be an invitation for evaporating water molecules to carry away an occasional hitch-hiking electron as they depart the surface ? Thus carrying negative charge to the bottom of the forming cloud ?


    i'm no expert - it's a question not an assertion
     
    Last edited: Jan 10, 2016
  13. Jan 10, 2016 #12
    Yup, that makes perfect sense. My next question is, for lightning as a closed circuit, do we see any difference in lightning's circuit compared to the circuits that lead up to intelligence? Natural or artificial? I'm guessing no?
     
  14. Jan 10, 2016 #13

    meBigGuy

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    Every circuit is different. Do they all follow the Electrical Laws of Physics? -- Of course. Do they all involve potential, current, capacitance, inductance, resistance, and energy in some configuration? --- Of course. Are there, within the laws of Physics, huge differences between circuits? Of course.

    At some geometries maybe the quantum effects are more significant to overall behavior, etc, but the all follow the same rules.

    Some circuits may be dominated by capacitance, some by inductance, some thousands of volts, some thousands of amps. SOme may have 3 components, some thousands. Can we model them and simulate them with variations in the basic components values, I think so.

    But, that's like saying all physical systems are the same, atoms, and galaxies. Not sure it is a meaningful statement.

    Not sure how else to answer the question.
     
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