Saturday, April 10, 2010

Whence pattern? -- Part 2

posted by Chet at 10:27 AM UTC

And so, for the time being at least, we live in a universe that is best understood from the bottom up. Particles interact in a great cosmic jiggle, purposelessly. Somehow out of this apparent chaos, this skitter and scatter, order arises. Galaxies spin. Stars shine. Continents move. Bacteria split and multiply.

And the human brain, the most complex thing we know about in the universe, tries to figure it all out. This we know: A tendency to order was built into the universe from the very beginning -- if there was a beginning.

The great majority of humans are put off by reductionistic explanations of the kind that have been dominant in science for the last four centuries. We prefer to imagine that the universe is on a preordained journey, like Dorothy and her friends on the way to the Emerald City -- if you want to understand the journey, start with the destination. But the opposite approach has proved far more successful in science: Start with the the chaos of a tornado, a girl, a tin man, a scarecrow and a lion. Let them interact and see what happens. The interactions between the players present themselves here and now for study. The idea of an Emerald City and all-powerful Wizard may be part of the mix, but an actual Emerald City and all-powerful Wizard may or may not exist somewhere over the rainbow.

To those who are put off by reductionism, I would recommend David S. Goodsell's marvelous book The Machinery of Life. Goodsell is a molecular biologist at the Scripps Research Institute, with an artist's gift for illustrating the molecular machinery of life, on a scale that takes us below and beyond available methods of imaging. What we see is breathtakingly beautiful.

A random paragraph:
The hundred trillion [sic] cells in our brain control everything, processing inputs from all corners of the body and making the proper outputs. This amazing network was wired in our first few months of life. As our brain developed as an embryo, the nerve cells multiplied and extended many connections to their neighbors, wiring the different portions of the brain involved in sense, motion, and thought. Then, as we grew and learned, our many childhood experiences strengthened connections, remodeling the brain into an efficient machine for biological computation. Together, these cells guide the cycles of sleep and wakefulness, they interpret signals as pleasurable or painful, they recognize colors and sounds and words, they remember things that we have done in the past, they figure out what to do in tricky situations in the present, and they plan where we are going in the future.
Goodsell's language veers toward the anthropomorphic: "interpret," "figure out," "plan." But he makes it clear that there is no "planning" in a top-down sense. Molecules bump around at random until they find a place where they fit, hand to glove. And wait until you see Goodsell's gorgeous watercolors of what's going on in every cell of your body. Bottom-up, yes, but what a bottom, and what an up!

Is there an Emerald City in the universe's future? Who knows. But what we have learned about molecular biology by bottom-up research is itself so mind-blowingly marvelous that to dismiss it as "mere reductionism" is to willfully close our minds to the here-and-now glory of creation.