Minimum Population For a High Tech Society?
So I was thinking about minimum viable population levels for a colony and it hit me that there are two industries that probably can't be made to work at small population, but that you need to have a high tech society. (I'm not asking about minimum genetic population, but minimum needed to be able to make all the stuff you need for a high tech civilization out of local resources. Two of the more involved parts of the supply chain are mentioned here, but there are other industries with similar issues. I'm interested in the local supply chain needed to make a viable colony.)
The first industry is semi-conductors. You need them for computers and embeded smart devices. But it isn't a cottage industry. A modern "fab" costs two billion and the cleanliness rules are staggering. Plus, even if you do have a fab, switching between products is difficult and prone to start up problems. 934
(Yield of working chips can be very low at first.) And you need a lot of different types of chips and you can't repurpose a production line used to make memory chips into one making cell phone chips. (The process is really different and the machines aren't the same.) So this is going to have to have multiple production lines, multiple groups of production workers and different groups of engineers, since an RF engineer is probably not that good at designing microprocessors. You could use a library of proven designs, but that means that your tech stagnates and frankly building some of the tools (vacuum systems and ion implanters) is going to be a very tricky industry in its own right. Figure you probably need thousands of people working at this full time to make it even marginally possible.
The second is the pharmaceutical industry. It has the same type of problem, there are thousands of products and the process to manufacture them can be very cranky and they need different processing equipment. So again you need multiple production lines, different groups of production workers and different groups of researchers. And bio-med research is even more specialized than chip design. Again, they could have a library of processes to make known drugs, but then again progress stagnates. This industry is even larger than the semi-conductor industry so I think it would take low tens of thousands to be able to make all the different drugs required.
So from this, I think we end up just two industries requiring thousands of people just to keep the wheels turning which points to a population in high tens to low hundreds of millions.
So I guess Mars, the Belt and the Moon are going to be dependent on Earth imports for a long time. 159