Nature's Fractals
(SFX: fractal-y music)  
     FRACTALS.  YOU'VE HEARD THE TERM, MAYBE EVEN SEEN BRIGHTLY COLORED
COMPUTER-GENERATED PICTURES OF THEM.  BUT WHAT ARE FRACTALS ANYWAY? IT'S A SIMPLE
IDEA.  ANYTHING THAT HAS THE SAME GENERAL SHAPE FROM ITS TINIEST DETAILS TO ITS
BROADEST FORM IS A FRACTAL.  THE BRANCHES OF A TREE, FOR EXAMPLE, FORM SIMILAR
PATTERNS NO MATTER HOW CLOSE UP OR FAR AWAY YOU LOOK.  JON PELLETIER IS A
GEOPHYSICIST AT CORNELL UNIVERSITY AND HE SAYS THAT MOTHER NATURE HAS CREATED
FRACTALS MORE BREATHTAKING THAN ANY THAT CAN FIT ON A COMPUTER SCREEN.  THE
SEEMINGLY RANDOM SHAPES OF COASTLINES, RIVERS, TREES AND LEAVES, OUR BLOOD
VESSELS, ALL CAN ALL BE EXAMPLES OF FRACTALS WITH AN UNDERLYING ORDER.

     Pelletier: "If you take a photograph of... the coastline... or a ... mountain range, and
you zoom in on a particular feature of that landscape... its impossible to tell by looking at the
profile what scale you're looking at."

     PELLETIER WANTED TO STUDY THE PATTERNS OF THESE NATURAL SHAPES USING THE SAME
KIND OF MATH THAT CAN DRAW FRACTALS ON A COMPUTER.  HE DEVELOPED EQUATIONS TO
DESCRIBE HOW FLOWING WATER CREATES FRACTAL SHAPES LIKE COASTLINES AND RIVER
BASINS. 

(Sfx: river)  

AS WATER CARVES THROUGH A LANDSCAPE IT PICKS UP PIECES OF ROCK AND SOIL, CARRIES
THEM ALONG FOR AWHILE, AND THEN DROPS THEM OFF FURTHER DOWNSTREAM.  THAT SOIL
CHANGES THE TERRAIN OF THE LAND AND FORMS NEW RIVER NETWORKS.  JUST LIKE FRACTALS,
WATER MOVES THE SAME WAY NO MATTER WHICH SCALE YOU LOOK AT IT AND SO THE
SEDIMENT PATTERNS WATER LEAVES BEHIND ALSO HAVE NO CHARACTERISTIC SCALE.  VOILA --
FRACTALS!

     Pelletier: "I've been looking at river basins along the Himalayan front which are very
different from . . . say the Mississippi river basin but are actually statistically similar.  The
relationship between the lengths of the little streams and the lengths of the big streams for
instance are very similar between these two very different environments."