1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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! :)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook