The experiment the thunder
We have a phenomenon accessible to the investigation, thunder, acoustic
shock which accompanies the longest electric arc - thunder.
The current interpretation of the acoustic shock is heating and sudden
dilation of atmospheric gas.
In order to prove this phenomenon, we need a closed enclosure, where a
magneto produces a small electric arc, by a dynamic microphone with a
membrane part of the wall of the enclosure for a pressure/electricity
translation and an oscilloscope.