The Norwegian Aurora Polaris Expedition 1902-1903

 

 

The Norwegian Aurora Polaris Expedition 1902-1903 by Kristian Birkeland.

The Norwegian Aurora Polaris Expedition 1902-1903by Kristian Birkeland.

By Kristian Birkeland. Publ. by H. Aschehoug & Co. Section 1 published 1908; Section 2 publ. 1913. Out of print.Online in full FULL TEXT

 

From the Preface

In his Preface, Birkeland writes:

"The knowledge gained, since 1896, in radio-activity has favoured the view to which I gave expression in that year, namely, that magnetic disturbances on the earth, and aurora borealis, are due to corpuscular rays emitted by the sun.

"During the period from 1896 to 1903 I carried out, in all, three expeditions to the polar regions for the purpose of procuring material that might further confirm this opinion. I have moreover, during the last ten years, by the aid of numerous experimental investigations, endeavoured to form a theory that should explain the origin of these phenomena. It is the results of these investigations that are recorded in this work, the first volume of which treats of terrestrial magnetic phenomena- and earth-currents, this section forming the first two thirds of the volume. The second volume will treat of aurora and some results of meteorological observations made at our stations.

"The leading principle that I have followed in this work has been to endeavour always to interpret the results of the worked-up terrestrial-magnetic observations, and the observations of aurora, upon the basis of my above-mentioned theory.

"[..] experimental investigations with a little magnetic terrella in a large discharge-tube, and by mathematical analysis, we have endeavoured to prove that a current of electric corpuscles from the sun would give rise to precipitation upon the earth, the magnetic effect of which agrees well with the magnetic field of force that was found by the observations on the earth.

"[..] The mathematical investigations, which, together with my experiments, are intended to make clear the movement of electric corpuscles from the sun to the earth, have been carried out, with a perseverance and ingenuity worthy of all admiration, by my friend, Professor STORMER, who will publish the complete results of his investigations in a special part of the present work.

From the Preface (Second section)

"The experimental investigations which at first were designed to procure analogies capable of explaining phenomena on the earth, such as aurora and magnetic disturbances, were subsequently extended, as was only natural, with the object of procuring information as to the conditions under which the emission of the assumed hello-cathode rays from the sun might be supposed to take place.

"The magnetic globe was then made the cathode in the vacuum-box, and experiments were carried on under these conditions for many years.

"It was in this way that there gradually appeared experimental analogies to various cosmic phenomena, such as zodiacal light, Saturn's rings, sun-spots and spiral nebular.

"The consequence was that attempts were made to knit together all these new discoveries and hypotheses into one cosmogonic theory, in which solar systems and the formation of galactic systems are discussed perhaps rather more from electromagnetic points of view than from the theory of gravitation.

"One of the most peculiar features of this cosmogony is that space beyond the heavenly bodies is assumed to be filled with flying atoms and corpuscles of all kinds in such density that the aggregate mass of the heavenly bodies within a limited, very large space would be only a very small fraction of the aggregate mass of the flying atoms there.

"And we imagine that an average equilibrium exists in infinite space, between disintegration of the heavenly bodies on the one hand, and gathering and condensation of flying corpusles on the other.