Universität Innsbruck

The Earth's Magnetism

Its Variations in Relation to Cosmic Rays Checked

In Nature, the English scientific weekly, for Aug. 21, Nobel Prize Winner Dr. Victor F. Hess of the Physical Institute of Graz, Austria, and his associate, Dr. A. Demmelmair, correlate some records made on the Hafelekar 2300 meters above sea level near Innsbruck, Austria, and at Cheltenham, Md., and Huancayo, Peru, between April 25 and April 30 of this year - five days of severe magnetic disturbances all over the earth.

Previously Dr. S. E. Forbush had reported in the Physical Review on a striking, almost simultaneous variation of cosmic rays and the earths magnetism at Cheltenham and Huancayo. By integrating Forbushs observations and cosmic ray strength, Drs. Hess and Demmelmair arrive at these important conclusions:

  • Between April 25 and 30 the strength of the cosmic rays varied at three widely separated stations in accordance with the variation in strength of the earths magnetism.
  • The magnitude of the variations in the strength of cosmic rays during the period in question (and hence during magnetically disturbed days in general) may amount to plus or minus 3 percent.
  • Lastly, these variations in the strength of the cosmic rays with the strength of the earths magnetism occur all over the planet.

So Drs. Hess and Demmelmair agree with Dr. Forbush that something has been discovered that physicists should follow up.

The Earth's Magnetism, New York Times, Sunday, August 29, 1937.