Kinematic Self-Replicating Machines
© 2004 Robert A. Freitas Jr. and Ralph C. Merkle. All Rights Reserved.
Robert A. Freitas Jr., Ralph C. Merkle, Kinematic Self-Replicating Machines, Landes Bioscience, Georgetown, TX, 2004.
3.6 Dyson Terraforming Replicators (1970, 1979)
In his Vanuxem Lecture in 1970, delivered just four years after Burks’ 1966 publication of the edited works of von Neumann on self-reproducing automata  (which brought von Neumann’s concepts to the attention of an even larger community of scientists and engineers), physicist Freeman Dyson suggested three large-scale applications of kinematic machine replicators as “thought experiments” for the 21st century :
Enceladus replicator (1970). “We have
the planet Mars, a large piece of real estate, completely lacking in economic
value because it lacks two essential things, water and warmth. Circling around
the planet Saturn is a satellite called Enceladus. Enceladus has a mass equal
to five percent of the earth’s oceans, and a density rather smaller than
the density of ice. It is allowable for the purposes of a thought experiment
to assume that it is composed of dirty ice and snow, with dirt of a suitable
chemical composition to serve as construction material for self-reproducing
“The thought experiment begins with an inconspicuous rocket, carrying a small but highly sophisticated payload, launched from the Earth and quietly proceeding on its way to Enceladus. The payload contains an automaton capable of reproducing itself out of the materials available on Enceladus, using as energy source the feeble light of the far-distant sun. The automaton is programmed to produce progeny that are miniature solar sailboats, each carrying a wide, thin sail with which it can navigate in space, using the pressure of sunlight. The sailboats are launched into space from the surface of Enceladus by a simple machine resembling a catapult. Gravity on Enceladus is weak enough so that only a gentle push is needed for the launching. Each sailboat carries into space a small block of ice from Enceladus. The sole purpose of the sailboats is to deliver their cargo of ice safely to Mars. They have a long way to go. First they must use their sails and the weak pressure of sunlight to fight their way uphill against the gravity of Saturn. Once they are free of Saturn, the rest of their way is downhill, sliding down the slope of the Sun’s gravity to their rendezvous with Mars.
“A few years later, the night-time sky of Mars begins to glow bright with an incessant sparkle of small meteors. The infall continues day and night, only more visibly at night. Day and night the sky is warm. Soft warm breezes blow over the land, and slowly warmth penetrates into the frozen ground. A few years later, it rains on Mars for the first time in a billion years. It does not take long for the oceans to begin to grow. There is enough ice on Enceladus to keep the Martian climate warm for ten thousand years and to make the Martian deserts bloom.”
Desert replicator (1970). “One of the byproducts of the Enceladus project is a small self-reproducing automaton well-adapted to function in terrestrial deserts. It builds itself mainly out of silicon and aluminum which it can extract from ordinary rocks wherever it happens to be. It can extract from the driest desert air sufficient moisture for its internal needs. Its source of energy is sunlight. Its output is electricity, which it produces at moderate efficiency, together with the transmission lines to deliver the electricity wherever you happen to need it….The progeny of one machine can easily produce a hundred times the present total power output of the United States, but nobody can claim that it enhances the beauty of the desert landscape….The rock eating automaton generates no waste heat at all. It merely uses the energy that would otherwise heat the desert air and converts some of it into useful form. It also creates no smog and no radioactivity. Legislation is finally passed authorizing the automaton to multiply, with the proviso that each machine shall retain a memory of the original landscape at its site, and if for any reason the site is abandoned the machine is programmed to restore it to its original appearance.
“If solar energy is so abundant and so free from problems of pollution, why are we not already using it on a large scale? The answer is simply that capital costs are too high. The self-reproducing automaton seems to be able to side-step the problem of capital. Once you have the prototype machine, the land, and the sunshine, the rest comes free. The rock-eater, if it can be made to work at all, overcomes the economic obstacles which hitherto blocked the large-scale use of solar energy.”
Industrial development kit (1970). “After its success with the rock-eating automaton in the United States, [the company] places on the market an industrial development kit, designed for the needs of developing countries. For a small down payment, a country can buy an egg machine which will mature within a few years into a complete system of basic industries together with the associated transportation and communication networks. The thing is custom made to suit the specifications of the purchaser. The vendor’s guarantee is conditional only on the purchaser’s excluding human population from the construction area during the period of growth of the system. After the system is complete, the purchaser is free to interfere with its operation or to modify it as he sees fit.” (Compare the “mini-plants” described in Section 3.7.)
“Another venture…is the urban renewal kit. When a city finds itself in bad shape aesthetically or economically, it needs only to assemble a group of architects and town planners to work out a design for its rebuilding. The urban renewal kit will then be programmed to do the job for a fixed fee.”
Replicating water plants (1979). In 1979, Dyson  added a fourth application of kinematic replicators – a modified version of Moore’s artificial living plants (Section 3.1) wherein each seagoing device “carries a large tank which it gradually fills with fresh water separated by solar energy from the sea…it is also prepared to use rain water as a bonus when available. Any boat with a full cargo of fresh water is programmed to proceed to the nearest pumping station, where it is quickly pumped dry and sent on its way.”
Freitas (1983) , Morgan (1994) , Nussinov et al. (1994) , Coppinger (1996) , and Gillett (1996)  have subsequently discussed using machine self-replicating systems for terraforming other planets, and related concepts have appeared frequently in the science fiction literature [693-696].
Last updated on 1 August 2005