Self-replicating systems thus hold the key to molecular engineering for structural materials, smart materials, the application of molecular manufacturing to power systems, user interfaces, general manufacturing and recycling, and so forth. The cellular machinery of life seems to be an existence proof for the concept of self-replication. Indeed, many proposed paths to nanotechnology involve using it directly. However, it is limited in types and specificity of reactions as compared with mechanosynthesis, and thus in the speed, energy density, and material properties of its outputs. Alternatively, one could select from the existing productive machinery of the industrial base, augmented with robotics to close a cycle in which factories build parts, which other factories build into robots, which build factories and mine raw materials.
Analysis Consider a system composed of a population of replicating machines.
Then and . There are some interesting implications of even so simple a model. First, if a replicator based on a single universal constructor is redesigned to have two cooperating constructors so it builds twice as fast, but in doing so it is made twice as complex, the growth rate is unchanged. On the other hand, suppose the architecture is enhanced by adding constructors that are special-purpose and thus both simpler and faster. As long as all units can be kept busy, na increases faster than s , decreasing g .