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Perfect Insulator

  1. Oct 24, 2011 #1
    I just some how fell into a wiki article about http://en.wikipedia.org/wiki/Insulator_%28electrical%29" [Broken] and then read the following statement:

    The question is, why is it that there are no perfect insulators? I thought things like plast, wood, didn't allow electricity to flow through at all, but of course physics does it again, turns your head completely upside down! :rolleyes:

    Could anyone explain this? I tried to google it but didn't find anything relevant.
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Oct 24, 2011 #2
    For one thing valence electrons eventually break loose at high enough voltages....that is, the medium becomes a conductor.

    A simple example is how a spark plug or lightning ionizes air which is a pretty good insulator (it must be since I don't get shocked sitting here at my computer with 120 volt ac nearby!!)

    Check here for some interesting background:


    Some interesting photographs...
  4. Oct 25, 2011 #3
    Ahha! I had no idea, thanks for the reply! :)
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