reversals, in which the north and south poles exchange position, to a small but definite, cyclic variation
in its magnitude at a "circadian" (about a day) rate. The interaction between the earth's field and those
of the sun and the galaxy impose other cycles with periods ranging from several weeks to centuries.
Magnetohydrodynamic factors, arising in part from the resonant cavity formed between the earth's
surface and the ionosphere, produce "micropulsations" in the magnetic field at frequencies ranging
from 0.01 to 20 hz. Transients (magnetic storms) occur in the total field in response to major solar
events such as flares, injecting large numbers of charged particles into the earth's field. Lightning
discharges in the atmosphere produce radio-frequency energy in the kilocycle range which propagates
along the lines of force of the magnetic field, literally "bouncing" back and forth between the northern
and southern hemispheres many times before dying out. A complex electrostatic field exists between
the surface of the earth and the ionosphere within which atmospheric atoms are ionized. Large
electrical currents flow within the earth itself (telluric currents), as well as within the ionosphere. All of
these factors are naturally present, and have been since the formation of the planet. The earth's
electromagnetic environment is rich and complex, with its interrelated factors continually varying in a
dynamic fashion. Our understanding of it is far from complete.
Long before the existence of the earth's magnetic field was known man had postulated "cosmic"
influences that affected all life. Visible astronomical events such as comets, the aurora, and the position
of the planets were associated with catastrophes such as plagues. Life was thought to be dominated by
unseen forces-generated in the stars. As knowledge of the magnetic and electric fields was acquired,
these similarly invisible forces began to be presented as the scientific basis for the older beliefs.
Mesmer, for example, in his use of magnetic fields, was actually trying to place the astrological
theories of Paracelsus (a truly great physician of the fifteenth century) on an acceptable scientific basis
by relating them to magnetism. Variations in the earth's magnetic field were believed to explain the
"obvious" influence of the moon on human life and behavior (lunatics, moon madness, etc.). The
infamous "ill winds" such as the Foehm and Simoon, producing physiological and psychological
changes in humans, were thought to act through their abnormal air ion composition.
It appeared highly unlikely, if not downright impossible, for such weak forces (the earth's
normal magnetic field averages half a gauss) to have any effect upon living things, particularly since
the generally accepted view of biology in the early years of this century completely excluded such
effects. However, as knowledge of the complexities of the earth's fields grew, so did the evidence for
some subtle, but extremely important relationships with living organisms. While changes in the natural
field do not produce the same kind of immediate, obvious biological effects as changes in the
atmospheric oxygen concentration, they do have profound effects upon the most basic functions of life.
Evolution of Life
Life began on earth some 4 billion years ago under conditions vastly different from the present
environment. The atmosphere most probably resembled that of Jupiter today, being much different in
composition and extent than at present. Most theories on the origin of life postulate the injection of
energy into this atmosphere in such forms as lightning, heat, and ultraviolet light, etc. leading to the
spontaneous formation of primitive organic compounds (1,2). These compounds would accumulate in
the warm seas, slowly coalescing and polymerizing into ever more complex molecules, finally forming
"protocells" (3). Considerable support for this hypothesis came from an experiment performed by
Miller in 1953 (4). Continuously circulating a mixture of simple gases such as those theorized to be
originally present, plus water vapor, through an electric spark discharge, he obtained a mixture of
ELECTROMAGNETISM & LIFE - 47