Cycles: Nature's Time Clocks

Edward Russell Dewey (1895–1978) was a Harvard economist who identified a number of cycles in the U.S. economy and started the Foundation for the Study of Cycles. Here are a sample of quirky cycles that apply to nature, gardening, astronomy, and other fields:

• One hundred years worth of records show that grasshopper abundance rises and falls rhythmically every 9.2 years.
• Historically, sunspots have been on a 12-year cycle, coinciding with the amount of rainfall in London, England.
• There is a 7.4-day cycle in the ability of bean seeds to take up water, which corresponds with the phases of the Moon. Peaks in water uptake occur at new moon, full moon, and intervening quarters. This lends credence to the age-old practice of planting by the Moon.
• Strangely, UFO sightings occur every 61 months, and in a regular pattern that is about 1500 to 2000 miles apart.
• Over a span of 133 years, bank deposits vary on a clear 9-year cycle, as does the number of cows kept for milk on U.S. farms.
• Every 9.6 years in Canada, there is a peak in the abundance of lynx, snowshoe rabbits, coyotes, martens, mink, muskrats, fisher cats, red foxes, and skunks.
• The index of international war battles shows a 6-year cycle recurring over a period of 2557 years. Also on a 6-year rhythm are steel production and whole-sale sugar prices.
• Precipitation in the U.S shows an 8-year cycle over 145 years of data. Also, oddly, cigarette production falls into the same cycle period.
• Records kept for more than 1300 years reveal that the Nile River floods highest on a regular 17 1/3-year cycle.

Perhaps understanding natural cycles can help us predict certain events in the future, such as natural disasters. It certainly underscores the fact that all things in life are interrelated—often in unexpected ways!