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Hi Pat,
The distance from which lightning can be seen is
dependent on three things - the intensity of the rain and cloud, the Earth's
curvature and the intensity of the lightning flash relative to
the environment. Of course, in the Australian outback where
there is no light pollution, the earth's curvature becomes more important, but
if you in a major conurbation such as London on New York, the
light pollution is so intense that lightning flashes that are a long way
away tend to get lost in the city's lights.
How far will a thunder clap travel?
Well, ten days ago a fuel tank at an oil depot in Hemel Hempstead (one of
London's commuter towns) exploded. There were reports that the
explosion was heard in the Netherlands (200 km away!). The reason
that the sound travelled so far was that there was temperature inversion and the
sound waves (and hence the energy) were reflected back to earth. The
result was that the sound energy per unit area was proportional to the
inverse of the distance travelled.
ie E = k/D where E is the energy per unit area, D
the distance from the source and k is a constant.
If however there was no temperature inversion
or reflecting layer, the sound energy per unit area would be proportional
to the square of the inverse of the distance.
ie E = K/D^2 (Symbols the same as
above)
In the latter case, the sounds intensity would drop
off far more quickly.
I trust that this is of
interest.
PS - I have never been to the Australian outback,
but I have been to remote parts of Africa, so I have assumed that the two are
similar).
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Title: Lightning and thunder
