Fractals Speak the Language of the Universe from the Ground Up
By Don Comis
April 10, 1998
Fractal geometry, a math of the rugged shapes of nature, has come to
the forefront in the past decade. It is being used to analyze
everything from stock prices and soil quality to cow temperatures.
Fractal geometry gets its name from the irregular fractals it deals
with, repetitive fragments that a computer can combine to draw natural
shapes from clouds to soil pores, the spaces between soil particles
through which air and water move.
Walter J. Rawls, who heads the
operated by USDA's Agricultural
Research Service in Beltsville, Md., is using fractal geometry
to predict soil water movement based on the geometry of soil pores.
Those same measurements are also being used to judge soil quality. The
measurements are made from thinly sliced sheets of soil encased in
Other ARS scientists are using fractal measurements to detect heat
stress in cows. Cows, like people, have random fluctuations in body
temperatures that resemble stock market fluctuations. Fractal line
dimensions range from 1 for a straight line to almost 2 for the
chaotic squiggle of body temperatures or stock prices.
Fractals can reveal when cows are losing their ability to regulate
their body temperatures-- when air temperature is around 80 degrees F.
This gives feedlot managers a vital clue to when to turn on the water
An article on fractal geometry project appears in the April issue of
ARS' Agricultural Research magazine. The article is also on
the World Wide Web at:
Scientific contact: Walter J. Rawls, Hydrology Laboratory,
Beltsville, Maryland, phone (301)504- 7490, fax (301) 504-8931,