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I Electromagnetic Field in Empty Space

  1. Feb 23, 2017 #1
    Our Professor said there will be still an electric field in empty space even without charges.Hows that possible.Space-time has a some quantum property that acts like this ?
     
  2. jcsd
  3. Feb 23, 2017 #2

    mfb

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    If there are no charges at all in the whole universe, there won't be an electric field. But there are charges in the universe. You have an electric field even in regions without charges due to charges elsewhere.
     
  4. Feb 23, 2017 #3
    I know but he meant something else ..
     
  5. Feb 23, 2017 #4
    He said aomething like this.Theres electric fields or some field and ıf charge comes there like a postive one It disturbs the field.And makes our normal things it was something like that I dont quite remember
     
  6. Feb 23, 2017 #5

    Dale

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    You may have misunderstood your instructor. I would ask him or her for clarification directly.
     
  7. Feb 23, 2017 #6
    Ok I will
     
  8. Feb 23, 2017 #7

    mfb

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    Well, technically "the electric field" is defined everywhere in space even without charges. Its strength is zero in that case. Usually this is called "no field", although mathematically the field is there.
     
  9. Feb 23, 2017 #8
    Make sense then...So ıf theres no charge in space-time its just there but "mathematically"
    If we put a charge in space time charge makes a electric field so it become "real" ?
     
  10. Feb 23, 2017 #9

    mfb

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    If we have charges somewhere, the value of the field becomes non-zero.

    A field that is zero everywhere doesn't do anything, at least in classical physics.
     
  11. Feb 23, 2017 #10
    I see..Thanks
     
  12. Feb 23, 2017 #11

    Baluncore

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    Any movement of electric charges somewhere, will result in a magnetic field due to the current flow and a change in the local electric fields. Those E and M fields will propagate outwards at the speed of light through empty space. Energy is being radiated in the direction of wave propagation.
     
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