Saturday, August 16, 2008

Tiny Machines

From the very large to the very small ...

Recently I attended a lecture on nanotechnology at the Miami Science Museum. On the program was a computer animation depicting the incredible variety of molecular processes that take place constantly in every cell of our bodies. You can see it for yourself courtesy of the multimedia project at Harvard University.

Our cells are busy places, each one a veritable city teeming with activity. But what I found most amazing was that these tiny structures, so small that in the animation you can see the individual atoms that make them up, appear to perform purposeful activities. They build things and take them apart, combine with one another to form new shapes -- one of them even appears to walk along a tube while towing a burden on its back, just like a person hiking with a knapsack.

How can this be? These things are far too small to know what they are doing. They certainly don't have brains, because they are just tiny parts of the cells that go to make up a brain. So how can they apparently perform useful work so industriously? Is this evidence of "Intelligent Design," proof that there is a Creator who built these things on purpose?

As tempting as it may be to believe that, the real story is both simpler and even more amazing. A medical friend who studies the function of neurons at the University of Miami explained that, for the sake of clarity, the animation omits all the other molecules that in reality fill up the empty spaces between the "purposeful" structures that they are trying to portray. These other molecules -- a lot of water and other substances, including simple organic compounds -- would appear to have no purpose at all. They simply jostle one another around like people on a crowded subway platform, in constant random motion.

So actually the "purposeful" structures are doing the same thing. They too are constantly being jostled. The only difference is that their shapes happen to flex and fit one another in ways that are productive to the living organism. They have affinities to some structures and aversions to others. When the random motions bring them into contact they stick or repel or combine simply because their molecular attractions compel them to do so. And if that sounds overly simplistic, you should watch this other animation of DNA replication to get an idea of how complex such "random" interactions can become.

It would appear that the Cosmic Designer's real magic trick was to give us laws of physical behavior that make the formation of everything we know inevitable. From atoms to stars and planets, and ultimately to intelligent life, all has been built upon a few simple cosmic rules laid down at the instant of the formation of the universe. From that moment, everything else was implicit.

Looked at in this light, it appears that once you have a livable world all you would have to do to create life would be to mix a soup of the right kind of molecules, apply heat, and stir. In fact, no one even has to stir the soup; it stirs itself. Over enough time, myriads of random collisions will result in simple components banding together to preserve and reproduce themselves. At last, given the opportunity, an intelligence is sure to arise from the murk and lift its gaze to the stars.

We know this result has happened here on Earth because, well, here we are. And no doubt it has happened, and will continue to happen, on an untold number of other planets throughout the cosmos. If not, in the words of Carl Sagan, "it would be an awful waste of space."

Confronted with the ambiguities of quantum mechanics, Albert Einstein famously said that he refused to believe that God played dice with the universe. Well, maybe in reality the dice were loaded, and God was bound to roll a perfect seven.

Even more amazing is that our intelligences have allowed us to discover all this, to make visible to ourselves even the invisible inner workings of our own bodies. Not only that, but we are now designing and building machines of our own choosing at these same tiny molecular scales. Scientists in laboratories are already working with "self-assembling" nano-devices that work remarkably like their biological counterparts. (For the latest predictions, check with the Center for Responsible Nanotechnology.)

The line between the living and the mechanical, between the created and the manufactured, between the accidental and the purposeful, soon will be indelibly blurred. Are we the designers or the designed? If it's true that "there is that of God in everyone," then perhaps both are one and the same.

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