Living Machines

But this may only be a stopgap measure on the road to developing completely synthetic sentience. Machine intelligence - fully equal (and quickly superior) to human intelligence in its ability to reason, to create, to amuse - is a frequent staple of science fiction as well as being a popular prognostication of technology futurists. There seems little reason to believe that it will not be realized. Silicon life, in the form of machine intelligence, would be free not only from the frailties and brief lifetimes of biology, but of greater import would not be constrained to the undirected and slow change of Darwinian evolution. A machine intent upon, say, increasing its memory, could do so by simply building and inserting more circuitry. It could improve itself by design, evolving in a Lemarckian, rather than a Darwinian manner. This would, of course, quickly result in vastly improved machinery.

I do not consider this scenario unlikely. Many technologically advanced cultures will disperse, thereby ensuring their survival. Survival will then give these societies the time to engineer synthetic intelligence, capable of rapid and directed self-evolution. Biological intelligence may indeed be rare. It may be “unlikely.” But even if this scenario has played out only rarely in the ten billion years of galactic history, it would have widespread consequences. Those consequences arise because such advanced intelligences could spread out.

The classic Drake Equation, as we have noted, assumes that the extraterrestrials will remain in the solar system of their origin. This is not unreasonable, assuming that the aliens are mortal beings with lifetimes short compared to the time needed to bridge the distances between the stars. Interstellar travel for biological beings is problematic (despite the suggestions of Hollywood) given the high speed necessary to achieve a tolerably short trip. But such restraints will not apply to machine intelligence. Even at non-relativistic speeds (~1% the speed of light), such sentience could spread throughout the galaxy within a few tens of millions of years. This is, of course, a thousand times less than the age of the galaxy, so there has been plenty of time for it to have occurred. Intelligence could have rapidly dispersed.

Contributed by: Dr. Seth Shostak