YOU may recall that yesterday in Weather Eye, mention was made of Byron's conclusion that
What men call gallantry, and gods adultery,
Is much more common where the climate's sultry.
Science, alas, can neither confirm nor deny this interesting assertion, but related topics have been found to have definite geophysical connections. There is evidence to suggest, for example, that the rate at which human beings procreate is influenced, for reasons quite unknown, by variations in terrestrial magnetism.
Changes in the orientation of the earth at various stages in its annual orbit result in a rhythmic variation in the intensity of its magnetic field, a rhythm which is most noticeable in very high latitudes within the Arctic and Antarctic circles. The magnetic index, as it is called, is high around the vernal and autumnal equinoxes, and at its lowest in June and December around the times of the summer and winter solstices.
Studies of Inuit Eskimos, who live in the extreme north of Canada, have revealed, apparently, that their conception rates vary rhythmically in a way that is similar to, but the inverse of the change in the magnetic index. Over the past 75 years, conceptions have been relatively few in the weeks adjacent to the equinoxes, but rise gradually in number to reach noticeable peaks around in June and late December.
Another study published a year or two suggests a relationship between the human birthrate and the well known 11 year sunspot cycle. Sunspots are dark circles, clearly visible on the face of the sun, that vary greatly in number and size their numbers increasing to a maximum and then decreasing again over a relatively fixed period of about 11 years. A study of birth rates in various regions of the world, with the figures suitably adjusted to remove cultural influences, show a clear pattern within each 11 year sunspot cycle a trough or minimum in the number of births was clearly apparent in year five, and a peak in evidence a few years later. The high birth rate coincided with high sunspot numbers, and the decrease in human reproductive activity corresponded to the sunspot minima.
Effort to relate reproductive success or otherwise to day today variations in the weather have been inconclusive. The best wisdom available in this context is an old German superstition which asserts that conception during fine weather guarantees the birth of a boy, while reproductive efforts during a spell of rain invariably produce a girl.