Simple rules can produce complex behavior, physicist Wolfram says
|Wolfram (Photo by Marcia Ledford, U-M Photo
The keys to understanding natural phenomena could lie in simple
rules and models, physicist Stephen Wolfram said in a speech during
which he promoted his controversial and popular new book, A
New Kind of Science.
Simple rules can produce fairly complicated
behavior, said Wolfram during the Oct. 8 talk at the Rackham
Building auditorium, which was hosted by the Center for the Study
of Complex Systems. That has some very important implications.
Wolfram discussed cellular automata, grids of black and white
that are governed by simple nonmathematical rules and which he thinks
can be made to do anything a real computer can do. Much of his book
is devoted to these 256 cellular automata, which form the basis
for his new science.
The ability of simple systems to perform complex functions and
to explain natural phenomena shows that science has been going in
the wrong direction, he said. His view is that natures rules
actually are quite simple, compared with the complexity of higher-level
Wolfram also discussed the Principle of Computational Equivalence,
an idea presented in his book, which states that all systems that
exhibit more than simple behavior have equivalent computational
powers. In theory, this means that even some processes with a low
level of complexity can have the sophistication to perform the same
computations as, say, a powerful computer.
The prominence of the book returns Wolfram to the spotlight in
the scientific world. He published his first scientific paper at
age 15 and received his Ph.D. in theoretical physics by age 20.
In 1981, he became the youngest recipient of a MacArthur Prize Fellowship.
He founded Wolfram Research Inc. in 1988 to market his Mathematica
Wolfram said he was pleasantly surprised by the popularity of
the book, which he said did not fit the conventions of the publishing
world. In the end, he said, I decided it was easier
just to print it myself. The first printing of 50,000 copies
quickly sold out, and the 1,200-page book became a bestseller.
While the book has been well-received by some, many scientists
are skeptical about Wolframs claims. U-M Physics Prof. Gordon
Kane says Wolfram has made progress in the research of cellular
automata and associated areas of computing theory. But it is not,
as the title of the book says, a new kind of science, Kane says.
Its always good to have new approaches, and I would
be happy if he could explain some phenomena about the laws of nature
or the universe that we dont now understand, Kane says.
But there are no new explanations in his book in these areas.
He speculates that his approach will provide new results, but he
does not distinguish carefully between getting new results and his
enthusiasm about asking questions new ways.