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Question regarding lightning

  1. Jan 11, 2005 #1
    Greetings--I have a few questions about lightning and sparks. =)

    (1) When you rub a glass rod on a piece of fur, I understand that there is a flow of electrons from one to the other. What property of these materials causes electrons to be released--i.e. is it because there are weakly-bound valence electrons, or does the thermal energy of the friction cause dissociation of electrons?

    (2) When you see a spark (or lightning) what causes the discharge to be visible? I imagine a spark to be a current between two points--but you can't usually *see* current. Is the illumination associated with some kind of radiation from electron acceleration? (Or perhaps excitation of orbital electrons causing them to radiate as they fall back down to their ground state?)

    Thanks much,
  2. jcsd
  3. Jan 11, 2005 #2


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    When you see the electricity going from one point to another point by means of a gas being a conductor (such as air), that is actually ionized gas, gas that has been so electricly charged, that it changes color and glows. Plasma globes use this for entertainment, inert gases (the noble gases) are in a sealed sphere, and a modified tesla coil ( http://voltnet.com/tesla/index.shtml go to the bottom for cool pictures) is in the middle.

    And this may be an interesting and relative article to you:

    From: http://www.aip.org/pnu/2004/split/712-2.html
    Last edited: Jan 12, 2005
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