Recherches sur les Taches du Soleil et Leur Origine
Birkeland, Kr., Recherches sur les Taches du Soleil et Leur Origine, Memorie della Societa Degli Spettroscopisti Italiani, 34, 14-18 (1905) (ADS)
(click on the image for a larger version)
Charged particles move in arcs following the Lorentz force in the
vicinity of the Earth, an early and prescient illustration of the
physics of the Aurora Borealis.
Doubtless this represents one of the earliest efforts in the field
of plasma astrophysics, from which the inspiration of the
Dungey cycle and a huge fraction
of the Archive's cartoons proceeded.
Here one sees an implied horizontal
electric current created by
the Larmor motions.
Note that the ADS link above does not actually contain this cartoon,
and the Archivist is not sure where he found it.
But the article is a good illustration of Birkeland's ideas.
Charged particles move in arcs following the Lorentz force in the vicinity of the Earth, an early and prescient illustration of the physics of the Aurora Borealis. Doubtless this represents one of the earliest efforts in the field of plasma astrophysics, from which the inspiration of the Dungey cycle and a huge fraction of the Archive's cartoons proceeded. Here one sees an implied horizontal electric current created by the Larmor motions.
Note that the ADS link above does not actually contain this cartoon, and the Archivist is not sure where he found it. But the article is a good illustration of Birkeland's ideas.