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Re: Tesla Coil toroid Size
> Now, I am far from an acoustics expert myself, but if we took a more
> related event, lightning. Does the acoustic bang come from the arc forming
> or from it collapsing. Everything I have read is that the collapsing arc is
> what makes the thunder(bang).
The bang comes from the arc heating the air very rapidly. The story
about the air collapsing into a vacuum is an old, old, erroneous theory.
The thunder comes from the rapidly expanding gases heated by the arc,
which starts as a shock wave and then "relaxes" into a sound wave within
a few meters. The "pitch" of the thunder is related to the size of the
arc column. The crackle of the thunder is because you hear the sound
from different parts of the lightning column at different times, and the
orientation of the sound wave is different relative to your direction
(the lightning arc column is "torturous").
Check out the book by Uman, "Lightning" for the best overall description
of everything you wanted to know about lightning. (Dr. Uman is actually
based at a college in Florida (I don't recall which), which is sort of
lightning heaven). Published by Dover, it's cheap in softcover (<$10).
If you have a reasonably big capacitor around that can store a kiloJoule
or so at 10-15 kV, you should do some exploding wire experiments. 10 kV
on a 14 uF cap will nicely explode a 1 meter length of #26 copper wire.
Just start with low voltage and gradually increase the voltage and
you'll see, hear, and feel the difference between "fusing" the wire and
"exploding".