Today, we'll explore a new concept: objects with fractional dimensions. Mike Martin explains.
Scientists have announced a precocious new offspring of magnets and plastic -- conveniently embedded in every card with a magnetic strip -- that could reinvent smart card technology and yield a dazzling new array of high-tech gadgets.
Plastic magnets, surrounded by unusual magnetic fields shaped like branches and snowflakes, may one day be the heart of computer hard drives small enough to power the denizens of nanotechnology: ultra-small surgical robots or tapes no larger than a molecule that house vast information libraries.
Where normal-size robots and credit cards have a definite three-dimensional shape, however, their Lilliputian counterparts may be so small that two, one or even fractional dimensions best describe them.
"A fractal is an object whose volume is not a simple product of its dimensions," explained Arthur Epstein, director of the Center for Materials Research at Ohio State University. Where "the volume of a rectangular box is its length times its width times its height, the volume of a snowflake is a fractal," Epstein explained. Fractal dimensions are fractional -- instead of 3-D or 2-D, they might be 1/2-D or 0.8-D.
The fractal magnetic field that surrounds the exotic plastic Joel Miller, a professor of chemistry at the University of Utah, and Epstein synthesized -- a hybrid compound of two tongue-twisting molecules called manganese tetra-phenylporphyrin and tetra-cyanoethylene -- "initially appeared to exist in 0.8 dimensions," said Miller. The plastic ultimately stabilized in 1.6 dimensions at a temperature of minus 269 degrees Celsius (minus 452 degrees Fahrenheit). These fractional dimensions yield fractured shapes, unlike those we normally attribute to magnetic fields.
I really would like to touch an object with 1.6 dimensions, but I guess I'll have to wait for a while.
Source: Mike Martin, NewsFactor Network, December 13, 2002
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