Originally published 23 October 1995
Which of the following strings of letters do you find most interesting?
- Aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa.
- One fish two fish red fish blue fish. Black fish blue fish old fish new fish.
- How sweet the moonlight sleeps upon the bank! Here will we sit and let the sounds of music creep in our ears.
- Rot a peck of pa’s malt had Jhem or Shen brewed by arclight and rory end to the regginbrow was to be seen ringsome on the aquaface.
- Vfg w eklpsi muc dvpk dbjhq a v sm i yu ncq bfox w wgbm ifiai lvdymssa lsa s s aiuro y astwaeqyw rtwvme gv k ljr jxbkdq.
No. 1 is pure repetition, presumably boring.
No. 5 is chaos; I programmed my computer to generate random letters and spaces. Not much interesting here.
The human mind is most at home somewhere between perfect order and perfect chaos. Young children will prefer No. 2, a passage from Dr. Seuss with lots of rhythm and simple pattern. A few adults profess to enjoy No. 4, from James Joyce’s Finnegans Wake, full of complex, deeply buried patterns.
My guess is that most of you picked No. 3, a snippet of Shakespeare.
And thereby hangs a tale.
Linguists tell us that all human languages are about equally complex, and the level of complexity is roughly equivalent to No. 3. My guess is that the complexity of languages matches the complexity of the human brain; that is, the richness of vocabularies and grammars is about that which the brain can process efficiently and without intolerable errors.
I’d also guess that the complexity of the brain matches the average complexity of the human environment.
We evolved in a world that is balanced somewhere between perfect order and perfect chaos. Our neural systems were presumably adapted by natural selection to recognize and process patterns in the environment.
If I am correct in these suppositions, then No. 3, from Shakespeare, is a pretty good match for nature’s average level of complexity.
Some parts of nature — crystals or the motions of planets — are close to No. 1. Their patterns are simple and easily described. This is the physicist’s domain, where science has had its most stunning successes.
Other parts of nature — for example, human consciousness and the development of embryos — are closer to No. 5. Their patterns are deep and complex, and have so far resisted complete analysis.
Which brings us to one of the most profound controversies raging in science today.
Some scientists — call them “reductionists” — believe that nature’s fundamental laws will be discovered near the No. 1 end of the spectrum.
High energy physicists and cosmologists, for example, like to imagine that in the first moments of creation the universe had a kind of perfect symmetry that quickly fractured into a few fundamental forces that continue to govern everything that happens in the world.
In this reductionist view, life and intelligence will eventually be explained by physics, when only we learn more about them.
Other scientists — call them “complexologists” — believe that the No. 5 end of nature’s spectrum has laws of its own, and no bottom-up explanations will suffice.
This group is best exemplified by scientists at the Santa Fe Institute in New Mexico who are exploring the new mathematics of chaos and complexity. More is different, they say. Phenomena emerge at the edge of chaos that will never be reduced to the laws of physics.
So far, reductionist science remains far and away the most successful. For all of the hype coming out of Santa Fe, complexologists have added very little to our understanding of how the world works.
But complexologists are confident, and my guess is that the future of science lies somewhere in their direction. Powerful, high speed computers will be key to the coming scientific revolution.
If the neural networks of the human brain match the average level of complexity in our environment, then understanding deeper levels of complexity will require supplementing the brain with artificial intelligence.
This is already happening. Computers are transforming the way science is done. It seems inevitable that they will also give rise to wholly new ways of thinking about the world — new kinds of top- down science.
It is not hard to imagine that someday we will have computers for whom Finnegans Wake is a work of Dr. Seussian simplicity, and which equal in their own complexity currently intractable patterns of life and mind.
At which point, we will have boot-strapped ourselves above the limitations of a brain adapted by evolution to a perceptual world of merely Shakespearean complexity.
