Re: [Phys-L] electricity in the atmosphere

[John Denker <jsd@av8n.com>]

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edition is 50 years out of date.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