Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What is St. Elmo's fire enrgy source?

  1. Nov 16, 2014 #1
  2. jcsd
  3. Nov 16, 2014 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

  4. Nov 16, 2014 #3
    I thought that in order to obtain useful energy, a current should flow. Yet, according to their description all this phenomenon happens before conditions for lightning are completely created. In my opinion a simple static field cannot generate an energy to do a work...
     
  5. Nov 16, 2014 #4

    russ_watters

    User Avatar

    Staff: Mentor

    Where are you getting the idea that this can generate "useful" energy/work? Or that it happens before there is a significant charge separation?
     
  6. Nov 16, 2014 #5

    Nugatory

    User Avatar

    Staff: Mentor

    That's not right - you can get light without any current flowing if you can just move enough charged particles around enough. The electrical field is quite strong enough to separate electrons from their parent atoms leaving us with a mixture of negative-charged electrons and positive-charged ionized atoms. Thermal motion in tis sea of charged particles then generates light.
     
  7. Nov 16, 2014 #6

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Basically? Your thought on this matter is mistaken.
    Unfortunately Nature does not care about opinions, yours or mine.

    Have you never seen a demonstration where a florescent light glows in an electric field, with no current passing through it?
    http://techtv.mit.edu/collections/p...uorescent-and-neon-tubes-in-an-electric-field
     
  8. Nov 17, 2014 #7
    Well, if there is a lights, we could convert this light into electricity with help of photocell and make it some useful work to do.
     
  9. Nov 17, 2014 #8
    Last edited by a moderator: May 7, 2017
  10. Nov 17, 2014 #9

    russ_watters

    User Avatar

    Staff: Mentor

    Sure, but very, very little. I'm not sure it could generate enough to call it "useful". Still, again, this doesn't imply a conservation of energy issue. I'm not seeing a problem here.
     
  11. Nov 17, 2014 #10
    Even amount of energy sufficient to power a pocket calculator is useful. I wanted to know when it came from. Is there a changes in electric field?
     
    Last edited: Nov 17, 2014
  12. Nov 17, 2014 #11

    russ_watters

    User Avatar

    Staff: Mentor

    Your article alludes to the source being the thunderstorm, but more specifically it is friction stripping and moving electrons around. Similar to when you shuffle your feet on a carpet:

    http://scijinks.jpl.nasa.gov/lightning/ [Broken]
     
    Last edited by a moderator: May 7, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: What is St. Elmo's fire enrgy source?
  1. What exactly is fire? (Replies: 21)

Loading...