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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"
http://www.feynmanlectures.caltech.edu/II_09.html
If you haven't recently read the Feynman lectures cover-to-cover,
I strongly recommend it.
*) Decent introduction at the qualitative level (no equations):
http://www.lightningsafety.noaa.gov/science/scienceintro.shtml
*) 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edition is 50 years out of date.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:
https://www.youtube.com/watch?v=vSCwiQWzMa0
Longer version:
https://www.youtube.com/watch?v=Tfryt3TILx0
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
contribution. -- 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.
https://www.av8n.com/physics/research-maze.htm
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