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Is it electric charge or only the friction?

  1. Apr 21, 2014 #1
    Hi all,

    When we rub two stones and get a spark , is there any chance of static charge accumulation or it is just the mechanical energy of friction is transferred in form of heat energy.

    Thanks in advance.

    Jayesh.
     
  2. jcsd
  3. Apr 21, 2014 #2

    UltrafastPED

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  4. Apr 24, 2014 #3
    Hi,

    Thanks and sorry for late reply.

    But what I am asking is that in primitive stage of civilization human being are generating fire by rubbing the stones only.

    I am asking for this phenomenon.
     
  5. Apr 24, 2014 #4

    UltrafastPED

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    Native Americans used a bow to twirl a wooden rod against another piece of wood with a matching hole; friction would heat the wood. When they judged it was hot enough they would drop in small pieces of dry material which would easily catch fire; this was then transferred ...

    see http://www.wildwoodsurvival.com/survival/fire/bowdrill/pmoc/basicbowdrill.html

    This is a friction technique.

    I am not familiar with the use of stones for starting fires - except for flint and iron.

    If you can provide a good reference, I can determine how the fire was started.
     
  6. Apr 24, 2014 #5

    davenn

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    That's ok for back to the iron age. But going back further than that required other methods

    It seems the Nth American Indian method of a "wood drill has been around for a much longer time.

    There's a severe lack of online info on the subject. First uses of fire seem to have been thought to have come from lightning started fires and volcanic sources.
    I read that there are hints of flint on flint as a started as well as a result of the seeing the sparks created by the "carving" of flint tools

    a bit of a digression from the original post but it would be great for a topic in another part of the forum if we had any anthropologists at PF ?? :smile:

    cheers
    Dave
     
  7. Apr 25, 2014 #6

    UltrafastPED

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  8. Apr 25, 2014 #7

    davenn

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