michaelm@3comvax.UUCP (05/16/86)
THE WORLD, THE FLESH, AND THE DEVIL Freeman J. Dyson Institute for Advanced Study Princeton, New Jersey V. Self-Reproducing Machinery In parallel with our exploitation of biological engineering, we may achieve an equally profound industrial revolution by following the alternative route of self-reproducing machinery. Self-reproducing machines are devices which have the multiplying and self-organizing capabilities of living organisms but are built of metal and computers instead of protoplasm and brains. It was the mathematician John von Neumann who first demonstrated that self-reproducing machines are theoretically possible and sketched the logical principles underlying their construction. The basic components of a self-reproducing machine are precisely analogous to those of a living cell. The separation of function between genetic material (DNA) and enzymatic machinery (protein) in a cell corresponds exactly to the separation between software (computer programs) and hardware (machine tools) in a self- reproducing machine. I assume that in the next century, partly imitating the processes of life and partly improving on them, we shall learn to build self- reproducing machines programmed to multiply, differentiate, and coordinate their activities as skillfully as the cells of a higher organism such as a bird. After we have constructed a single egg machine and supplied it with the appropriate computer program, the egg and its progeny will grow into an industrial complex capable of performing economic tasks of artibrary magnitude. It can build cities, plant gardens, construct electric power-generating facilities, launch space ships, or raise chickens. The overall programs and their execution will remain always under human control. The effects of such a powerful and versatile technology on human affairs are not easy to foresee. Used unwisely, it offers a rapid road to ecological disaster. Used wisely, it offers a rapid alleviation of all the purely economic difficulties of mankind. It offers to rich and poor nations alike a rate of growth of economic resources so rapid that economic constraints will no longer be dominant in determining how people are to live. In some sense this technology will constitute a permanent solution of man's economic problems. Just as in the past, when economic problems cease to be pressing, we shall find no lack of fresh problems to take their place. It may well happen that on Earth, for aesthetic or ecological reasons, the use of self-reproducing machines will be strictly limited and the methods of biological engineering will be used instead wherever this alternative is feasible. For example, self-reproducing machines could proliferate in the oceans and collect minerals for man's use, but we might prefer to have the same job done more quietly by corals and oysters. If economic needs were no longer paramount, we could afford a certain loss of efficiency for the sake of a harmonious environment. Self-reproducing machines may therefore play on Earth a subdued and self-effacing role. The true realm of self-reproducing machinery will be in those regions of the solar system that are inhospitable to man. Machines built of iron, aluminum, and silicon have no need of water. They can flourish and proliferate on the moon or on Mars or among the asteroids, carrying out gigantic industrial projects at no risk to the earth's ecology. They will feed upon sunlight and rock, needing no other raw material for their construction. They will build in space the freely floating cities that Bernal imagined for human habitation. They will bring oceans of water from the satellites of the outer planets, where it is to be had in abundance, to the inner parts of the solar system where it is needed. Ultimately this water will make even the deserts of Mars bloom, and men will walk there under the open sky breathing air like the air of Earth. Taking a long view into the future, I foresee a division of the solar system into two domains. The inner domain, where sunlight is abundant and water scarce, will be the domain of great machines and governmental enterprises. Here self-reproducing machines will be obedient slaves, and men will be organized in giant bureaucracies. Outside and beyond the sunlit zone will be the outer domain, where water is abundant and sunlight scarce. In the outer domain lie the comets where trees and men will live in smaller communities, isolated from each other by huge distances. Here men will find once again the wilderness that they have lost on Earth. Groups of people will be free to live as they please, independent of governmental authorities. Outside and away from the sun, they will be able to wander forever on the open frontier that this planet no longer possesses.