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Re: [Phys-L] electricity in the atmosphere

On 02/09/2018 06:47 PM, Derek McKenzie wrote:

I particularly appreciate the number estimates, as well as the idea of modeling
the phenomenon as a spherical capacitor.

For those who want to know more about the model.....

*) Magnificent reference:
"Electricity in the Atmosphere"

If you haven't recently read the Feynman lectures cover-to-cover,
I strongly recommend it.

*) Decent introduction at the qualitative level (no equations):

*) The books by Uman are useful but even the latest "revised"
edition is 50 years out of date. I haven't seen the 700-page
tome by Rakov and Uman but I gather it is more up-to-date.

*) Sprites in the upper atmosphere were predicted in 1921
by C.T.R. Wilson but not observed until 1989, and are
still a hot topic of research:

Longer version:

That NOVA episode gives a realistic portrayal of scientists
doing their job. In particular, ask your students how they
would feel if they spent years putting together a team and
building equipment, then when the conditions are right staying
up all night and spending an additional $100,000.00 to carry
out the mission, and coming back with ... nothing! If you
don't know what that feels like, you don't know what it's like
to be a scientist.

Most remarkably, NOVA did not leave out the painful part of
the story.

A few nights later, good conditions come around again, so
they carry out the mission again, and come back with ... data.
Gorgeous, highly informative data.

Additional points to tell students:
-- Not all physics was done in the 1600s. There are still
interesting unanswered questions.
-- Physics is mostly a team sport; you don't have to be a
lone genius like Galileo or Newton or Einstein to make a
-- A lot of it requires building fancy instruments and
exploiting modern technology.
-- OTOH it usually doesn't require CERN-sized teams or
CERN-sized instruments. Sometimes a Gulfstream-V full
of fancy cameras will do nicely.
-- There is joy at the end of the rainbow, but you have
to tolerate a lot of risk and pain before you get there.
This requires strength of character. Technical skill is
not enough.
-- It must be emphasized that exploring blind alleys is part
of the cost of obtaining information. A mission that comes
back with no data of the desired kind is not a mistake and
not a waste. Scientists take calculated risks, carefully
balancing risk versus reward. Don't take any more risk than
necessary, or any less.