Alfven & magnetic fields

Jerry Wayne Decker ( jwdatwork@yahoo.com )
Sat, 25 Sep 1999 09:20:00 -0700 (PDT)

Hi Folks!

Here is a superb document about Hans Alfven and some
of his groundbreaking theories and research;

http://www.millenngroup.com/repository/cosmology/alfven.html

....in the early 1930's, cosmic rays were commonly
thought to be gamma rays filling the entire universe.

However, when they were discovered to be charged
particles, Alfven offered in 1937 the novel suggestion
that the galaxy contained a large-scale magnetic field
and that the cosmic rays moved in spiral orbits within
the galaxy, owing to the forces exerted by the
magnetic field.

He argued that there could be a magnetic field
pervading the entire galaxy if plasma was spread
throughout the galaxy. This plasma could carry the
electrical currents that would then create the
galactic magnetic field.

Alfven concluded that an electromagnetic wave could
propagate through a highly conducting medium, such as
the ionized gas of the sun, or in plasmas anywhere.

However, in 1942 when Alfven published his discovery,
Maxwell's theory of electromagnetism was a
well-established edifice, a subject for textbook
pedagogy and engineering applications.

It was "well known" that electromagnetic waves could
penetrate only a very short distance into a conductor
and that, as the resistance of a conductor became
smaller and smaller, the depth of penetration by an
electromagnetic wave would go to zero.

Thus, with an ideal electrical conductor, there could
be no penetration of electromagnetic radiation. But
Alfven was proposing a form of electromagnetic wave
that could propagate in a perfect conductor with no
attenuation or reflection.

Birkeland's ideas might have faded completely had it
not been for Hannes Alfven, who became involved well
after Chapman's ideas gained predominance.

Alfven kept insisting that Birkeland's current system
made more sense because downflowing currents following
the earth's magnetic field lines were required to
drive most of the ionospheric currents. The issue was
not settled until 1974, four years after Chapman's
death, when earth satellites measured downflowing
currents for the first time.

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as I am writing from my work email of
jwdatwork@yahoo.com.........thanks!
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