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Does the universe has a capacitance?

  1. Mar 8, 2012 #1
    Does the universe has a capacitance?
  2. jcsd
  3. Mar 8, 2012 #2
    The units of permittivity of space can be written as farads/meter.
  4. Mar 8, 2012 #3


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    so, do we multiply [itex] \epsilon_0 [/itex] by the number of meters across the known universe (which might be something like [itex]c[/itex] times 13.7 billion years)? is the capacitance of the universe growing as the universe expands?
  5. Mar 9, 2012 #4
    That is what I meant.

    I don't even know if it is a valid question but it occurred to me a few hours ago while I was trying to understand permittivity, which appears as a proportionality constant in the Gauss' Law.
  6. Mar 9, 2012 #5


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    No, because it does not have an electrically contiguous surface.

    The capacitance of a thing defines its electrical potential given a state of charge on it. As the charge cannot distribute itself on any 'universal' structure (as no such structure exists), so there can be no 'universal' capacitance.
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