The Theory of Magnetic Storms and Auroras

Abstract

No one will disagree with Prof. Alfvén when he stresses the desirability of attempting scale-model experiments of geophysical phenomena in the laboratory. Unfortunately, experience shows that unambiguous experiments of this type are hard to make : a recent study of such an experiment devised by Chapman¹ to test theories of magnetic storms reveals some of the difficulties. It would seem that in the field of low-pressure physics, Nature still provides the laboratory best suited for illustrating fundamental principles in action. Certainly, to date, all scale-model attempts to illustrate theories of magnetic storms have yielded ambiguous results : in Alfvén's own recent words², “we ought to be careful in applying a result from a scale-model experiment to Nature”.