An interesting result of Stephen Wolfram's work with cellular automata. It states:
Almost all processes that are not obviously simple can be viewed as computations of equivalent sophistication. Put more generally, this means that any system can be seen as performing some computation (ie, a computer, weather, the human brain, etc), and that, if it reaches some relatively low threshold in complexity, it will attain a maximum in computational power. Thus, most systems have the same computational power (akin to Universal Turing Machines) and are said to be computationally equivalent. A consequence of this is that no computation performed in this Universe can be more powerful than the computation performed by the Universe, if it were taken to be some (rather large) computer.
A very detailed treatement of this idea can be found in his book A New Kind of Science1.
- Wolfram, S. A New Kind of Science. Champaign, IL: Wolfram Media, 2002. ISBN 1-57955-008-8.