[ARC5] An "Extra Class" Question:

[Bill Fuqua]

Speaking of sparks gaps remained me of something.
  The problem with spark gaps is that the breakdown voltages are not always 
so precise.
Hertz discovered this in the 1880's By accident and necessity.
He used a calibrated spark gap determine the voltage of the received signal 
in his
experiments that were intended to determined if a magnetic field was 
created by the
virtual current in the dieelectric materials in capacitors. This research 
led to discovery of
the nature of radio waves and the fact that they behaved the same as light 
waves.
   He found one day that his calibrated spark gaps were arcing over at a 
lower voltage than
they should have. That led to the discovery that an open window curtain was 
letting in Sun
light and after further investigation that it was the UV component of that 
Sun light that was
the culprit.  The solution was to close the curtains and continue with the 
research. However,
in the process of being diverted to something else he discovered the photo 
electric effect.
Google "Hertz Effect".
   He got a grant to research this question about the virtual current in 
dielectric materials and ending up
making even a greater discovery. I don't know if he ever really answered 
the original question.
   To him, at the time, Photoelectric effect was a nuisance, but look at 
your copier, cell phone
camera, etc. We could not get along without it.
   Another things that oddly affects spark gaps are smoke, barometric 
pressure and humidity.
We once had a guy that tested our ionization chambers used to detect air 
borne tritium by blowing smoke from his pipe into
them.
   I have a copy of  H.Hertz's translated lab notes. Very interesting reading.

73
Bill