[PD] pd thunder

[Kyle Klipowicz]

Yes. A rapid expansion and collapse of air pressure would most
definitely be inseparable causes.

~Kyle

On Wed, Feb 6, 2008 at 10:30 AM, Andy Farnell
<padawan12 at obiwannabe.co.uk> wrote:
>
>
>  Yes. That's part of it.
>
>  According to Ribner and Roys first paper the vacuum collapse model
>  is refuted - well, they don't use that exact word - more like
>  they suggest it is replaced...
>
>  "As recently as the late 1800's, four theories of thunder were in competition:
>  The vacuum collapse theory, the explosive electrolysis theory (recombination
>  of electrolyzed water), the steam  expansion theory, and the Ohmic heating
>  theory (resistive heating and consequent expansion due to heavy current
>  discharge). The last, proposed by M. Hirn in 1888, is now accepted, being
>  supported by a large body of consistent experimental data and theory."
>
>  However I disagree, since it is one necessary flip side of the favoured
>  primary cause - collapse happens after the expansion (in a remarkably
>  short time frame) Therefore the vacuum collapse theory must be incorporated
>  into a complete model, being responsible for the negative impulse of the N-wave.
>
>  "One prevailing theory proposed that thunder was produced when lightning,
>  passing through the air, caused a vacuum to form. When this vacuum collapsed,
>  the air rapidly rushing back in produced a thunderous explosion."
>
>  http://www.islandnet.com/~see/weather/elements/thunder1.htm
>
>  As I see, the unipolar vacuum collapse theory only makes sense, if there
>  is a chemical reaction that removes CO2, H2O, O2 or N2 from the atmosphere,
>  (and one assumes no matter is transformed to energy) - well NO2 and O3
>  are produced, but that doesn't account for the volume.
>
>  Vacuum collapse theory ?? (< 1800)
>  Steam theory of R.V. Reynolds (1903)
>  Electrolysis theory R.S. Mershon (1870)
>  Ohmic heating theory M. Hirn in 1888
>
>  In a 1888 article in Scientific American, M. Hirn advanced the theory that
>
>  "thunder is due simply to the fact that the air traversed by an electrical
>  spark, that is, a flash of lightning, is suddenly raised to a very high
>  temperature, and has its volume, moreover, considerably increased. The
>  column of gas thus suddenly heated and expanded is sometimes several miles
>  long, and as the duration of the flash is not even a millionth of a second,
>  it follows that the noise burst forth at once from the whole column, though
>  for a observer in any one place it commences where the lightning is at the
>  least distance....the beginning of the thunderclap gives us the minimum
>  distance of the lightning, and the length of the thunder clap gives us the
>  length of the column."
>
>  So, in summary, there is no single cause and all these theories
>  are sensibly incorporated into the process.
>
>  Least likely is perhaps Mershon - but in a plasma we know the gasses
>  are monatomic and there is still a lot of stuff to be discovered in
>  plasma physics, so he may have been on to something after all.
>
>  Reynolds clearly contributes something sensible, because water vapour
>  has the highest thermal expansive coefficient.
>
>  And the vacuum collapse theory _must_ be incorporated if the Ohmic
>  expansion theory holds.
>
>  a.
>
>
>
>
>
>
>
>
>
>
>
>  On Wed, 6 Feb 2008 16:00:58 +0100
>  plessas at mur.at (Peter Plessas) wrote:
>
>  > * Andy Farnell <padawan12 at obiwannabe.co.uk> [2008-02-05 23:33]:
>  > >
>  > >
>  > > You're spot on there. I will develop the stereo image as I work on
>  > > the environment model.
>  > >
>  > > But interestingly enough, lightning _is_ an explosion, one hell of
>  > > a big explosion. The plasma is as hot as the Sun for an instant and
>  > > that's why the air expands, the energy in a lightning bold makes most
>  > > bombs seem like little fireworks. The difference is, and this is
>  > > unusual, it radiates in a cylinder not a sphere, and sound comes
>  > > from a simultanoeus extent (because the bolt moves at the speed of
>  > > electricity which is closer to the speed of light than the speed of
>  > > sound)
>  >
>  > Isn't the noise happening when the light/plasma channel is collapsing
>  > after the lightning happened?
>  >
>  > regards, Peter
>  >
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>  --
>  Use the source
>
>
>
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