The industrial demands of space settlement are very large. In the 1970s, Gerald K. O'Neill and his students designed a possible industrial infrastructure to build massive orbital colonies and solar power satellites. Even more daunting are the proposals for Solarian-scale projects, such as a halo/ring-world, or a Dyson Sphere/Shell. Using traditional factory-based manufacturing, such projects are nearly impossible. Luckily, however, a simple self-replicating fabber would make these projects possible, and perhaps even easy.
According to Adrian Bowyer (of RepRap), the three most important aspects of self-replicating fabbers are that:
- The number of them in existence and the wealth they produce can grow exponentially,
- The machine becomes subject to evolution by artificial selection, and
- The machine creates wealth with a minimal need for industrial manufacturing.
Many articles written about fabbers state that fabbers will never replace factories because factories can turn out a lot more products than a fabber. That is true. A factory built upon the technology of mass production can produce thousands of products per hour, while a fabber may not be able to print more than about 20 objects per day. Now let's suppose that a fabber can copy itself. If it can copy itself enough times, then it will eventually have the capability to produce far more than all of the factories on Earth put together.
If it takes 24 hours for a fabber to copy itself, then after one day, there will be two fabbers. During day two, the two fabbers will copy themselves, leaving four. During day three, the four fabbers will self-replicate, leaving 8 total fabbers. After a week, there would be 128 fabbers. In two weeks, there would be 16,384 fabbers. In two weeks, you have about the manufacturing capacity of a factory. If you let it continue for two months, you will have 1,152,921,504,606,846,976 fabbers. That is over 1 quintillion fabbers.