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The Body Electric
We likely have yet to discover many other ways that energy cycles in
the solar system affect life on earth. They may strongly affect the out-
break of disease, for example. The last six peaks of the eleven-year sun-
spot cycle have coincided with major flu epidemics. A Soviet group
under Yu. N. Achkasova at the Crimean Medical Institute, working
with astronomer B. M. Vladimirsky of the Crimean Observatory, has
found a connection between the sun's magnetic field and the Escherichia
coli bacteria that live in our intestines and help us digest our food. The
Russians found the bacteria grew faster when the sun's field was positive,
or pointing toward earth, and slowed down when it was negative. Two
days after the passage of each sector boundary there was a dip in bacterial
growth corresponding to the maximum geomagnetic turbulence. The
data also showed a decline in growth in response to large solar flares.
Other Russian scientists have drawn a tentative correlation between the
sector cycle and reports from two groups of persons with neurological
diseases. The patients felt worse within sectors of positive polarity, when
bacteria seemed to grow faster. Life's geomagnetic coupling to heaven
and earth is apparently more like a web than a simple cord and socket.
The Attractions of Home
An animal's biocycles must be appropriate for its environment if it's to
survive, so they must be precisely tuned to its geographic location. We
might suspect, therefore, that many creatures would use magnetic infor-
mation for their sense of place. A great deal of recent work has shown
that they do. A built-in compass helps guide them in foraging or other
local business, as well as migration over much longer routes. The latter
feats often rival those of any modern navigator. Monarch butterflies
travel from Hudson Bay to South America straight across the Caribbean
without ever getting lost. The arctic tern breeds in summer on the
northern ice cap, then moves to Antarctica for the other hemisphere's
summer, flying 11,000 miles each way. Some salamanders, only inches
long and built very low to the ground, travel up to 30 miles of rugged
mountain country in California to set up housekeeping, then return to
their home stream to breed. Such activities are hard to experiment with,
however, so we've learned more about day-to-day travel.
Karl von Frisch was the first to attack the problem, with his famous
1940s studies of the honeybee dance, which won him a Nobel Prize in
1973. He established that on clear days bees navigated by combining
the sun's angle with their sense of time, the way Boy Scouts are taught