I touched a key. "Here's a random deployment of playing pieces." About a third of the sixty-four squares sprouted circular occupants. "Now, look: each occupied square has eight neighboring squares, including the diagonal corners, right? Now, consider three simple rules: a given square will remain unchanged-either occupied or vacant-if precisely two of the neighboring squares are occupied. And if an occupied square has three neighbors, it remains occupied. In all other cases, the square becomes empty if it isn't already, and if it
is empty, it remains empty. Got it?"
"Yes"
"Okay. Now let's expand the board. Instead of an 8-by-8 matrix, let's use 400 by 300; on this monitor, that lets every square be represented by a two-by-two pixel cell. We'll show occupied squares by white cells and unoccupied squares by black cells."
I tapped a key and the checkerboard apparently receded into the distance while at the same time extending to all four corners of the screen.The grid of the board disappeared at this resolution, but the random pattern of the lighted and unlighted cells was obvious.
"Now," I said, "let's apply our three rules." I tapped the space bar and the patterns of the dots shifted. "Again," I said, tapping the spacebar, and again the pattern shifted. "And once more." Another tap; another reconfiguring of the dots on the screen. Hollus looked at the monitor and then at me. "So?"
"So this," I said, and tapped another key, and the process began repeating itself automatically: apply the three rules to every piece on the board, redisplay the new configuration, apply the rules again, redisplay the revised configuration and so on. It only took a few seconds for the first glider to appear. "See that group of five cells?" I said. "We call that a 'glider,' and - ah, there's another one." I touched the screen, pointing it out. "And another. Watch them move."
And, indeed, they did seem to move, staying as a cohesive group as they shifted from position to position across the monitor.
"If you run this sumilation long enough," I said, you'll see all sorts of lifelike patterns; in fact this game is called Life. It was invented in 1970 by a mathematician named John Conway; I used to use it when I taught evolution at the University of Toronto. Conway was astonished by what those three simple rules generated. After enough iterations, something called a 'glider gun' will appear - a structure that shoots out new gliders at regular intervals. And, indeed, glider guns can be created by collisions of thirteen or more gliders, so, in a way, the gliders reproduce themselves. You also get 'eaters,' which can break up passing objects; in the process, the eater gets damaged, but after a few more turns, it repairs itself. The game produces movement, reproduction, eating, growth, the healing of injuries, and more, all from applying those three simple rules to an initially random selection of pieces."
"I do not see the point you are trying to make," said Hollus.
"The point is that life - the apparent complexity of it all - can be generated by very simple rules."
"And these rules you keep iterating represent precisely what?"
"Well, the laws of physics, say..."
"No one disputes that seeming order can come out of the application of simple rules. But who wrote the rules? For the same universe you are showing me you mentioned a name-"
"John Conway."
"Yes. Well, John Conway is the god of that universe, and all his simulation proves is that any universe requires a god. Conway was the programmer. God was also a programmer; the laws of physics and physical constants he devised are our universe's source code. The presumed difference between your Mr. Conway and our God is that, as you said, Conway did not know what his source code would produce until he compiled and executed it, and he was therefore astounded by the results. Our creator, one presumes, did have a specific result in mind and wrote code to produce that result. Granted, things have not gone as precisely as planned - the mass extinctions seem to suggest that. But, nontheless, it seems clear that God deliberately designed the universe."
"You really believe that?" I asked.
"Yes," said Hollus, as he watched more gliders dance aross my computer screen. "I really do."
Excerpt from
Calculating God by Robert J. Sawyer
