In the episode entitle "Firewalker," from the second season of The X-Files, a team of volcanologists uncovers a strange organism living in the depths of a volcano. As usual Mulder and Scully are sent to investigate and barely escape with their lives. What they realize, over the course of 44 minutes, is that this life form is based not on carbon, as is all life on Earth, but its cousin: silicon.

This story, or one of many variations like it, is common in the sci-fi arena and has spawned a number of imitators, including life based on the unlikely xenon. Leaving aside the possibility of life inside high quality lamps, recent developments in microprocessor technology make it worth considering a flavor of life anchored in something other than carbon.

Organic chemistry, and its complementary organic compounds, is based in carbon. All life, as far as we know, is similarly based. This makes sense given that there seems to be about 10 times as much carbon in the universe as silicon. But the mere abundance of carbon is not reason enough that life should be based on it. Indeed, the inner planets of our solar system are comprised mostly of silicon, or its derivates, and are quite poor in carbon.

However, when it comes to forming complex, long-chain molecules, there seems to be no better atom than carbon. Except when in sulfuric acid environments, silicon molecules tend to be very unstable. This is partly due to silicon's large atomic structure. With a greater mass and wider atomic radii, silicon is at a distinct disadvantage where forming the all-important double- and triple-covalent bonds are concerned.

As we can safely say that silicon-based chemistry will not yield alternative organisms on this planet, at least not without some sort of cataclysmic planetary shift, we can turn our attention to the looming threat of machine dominance.

A team of scientists from I.B.M. (of course) and the Georgia Institute of Technology (who knew?) has unveiled a microchip capable of operating at up to 500 gigahertz. For reference, the computer this article was written on clocks in at a mere 1 GHz, far too slow to require the liquid helium coolant that kept the new chip chilled to near absolute zero.

Though staggering, this computational power, equivalent to about half a trillion calculations per second, is miniscule when compared to that of the human brain, which may perform 100 trillion instructions per second. Given the difference between the two, and the current lack of insight into the functions of the brain, a direct comparison such as this must be taken with a rather large amount of salt. However, given the pace of technological growth in the realm of processing power there may well be, within the space of two or three decades, processors that surpass the theoretical computational limit of the human brain.

To return to the science fiction mentioned above, at what point could cycles pre second be redefined as thinking? Could electricity flowing through silicon give rise to artificial life?

In it's most simple form this concept of building a living thing from artificial parts is akin to Intelligent Design. Intelligent beings (humans), the theory goes, would create a, er, species of beings which would then reproduce on their own.

Surprising though it may be, research into this field actually predates the invention of the computer. As early as 1737 a man named Jacques de Vaucanson was experimenting with automatons. His most famous creation, The Digesting Duck.



The duck, which had over 400 moving parts, could drink, swim, quack, eat, digest, and (you guessed it) defecate. While it was something of a marvel around Europe at the time, the duck did not fit the strict definition of artificial life, in that it could not respond to its environment in a way it was not built to.

With the advent of modern computing, around the 1970's, it became possible to program a computer with a series of instructions to create cellular automatons. This type of software, the most famous of which is the Game of Life invented by John Horton Conway (no, not that one), allows the "player" to set an initial state (an environment) and watch as the program responds to that state.



In this game, and many others like it, the software literally evolves based on a set of a few simple instructions.

In recent years the programming of artificial life has advanced tremendously and found an unlikely home in the special effects industry. The blockbuster Lord of the Rings, for example, used a sophisticated software package called MASSIVE to simulate thousands of orcs and humans engaged in battle. The software allowed the CGI creatures to make simple decisions in a virtual environment that mimic those real humans can make.

Decisions like who to hit with a sword, where to hit, or whether to run away, were all made by the individual entities that existed within the virtual Middle Earth. They were, in a very constrained way, thinking for themselves.

However, to return to the questions posed earlier: could any of those actions be taken to be thought? Does the ability to make decisions informed by the status of the world mean the decider is thinking? At the present moment, it would seem the answer is no.

But, with a few more leaps in computing power and software programming it may be possible that we'll see artificial life that exists not as being of silicon, but beings within it.

« Previous Next »