From “I Like to Build Alien Artifacts,” a Stephen Wolfram interview that ran in the European earlier this year, a segment about the possibilities of molecular-level computing:

“The European: I want to go back to the idea of the Turing machine. One of your arguments is that very simple programs can produce very complicated results – programs so simple that they could be encoded in a cell’s genome, for example. 

Wolfram: Our intuition tends to be that we have to go through a lot of effort to build something that is complicated. But nature is very complex without going through a lot of effort: Evolution seems very complicated on a large time-scale, but the actual processes are not. They simply work and unfold and lead to new species. That was always a mystery to me, so a few years ago I began to experiment to see whether simple programs could produce very complex patterns of behavior. The question is: Is that how nature does it? I got a lot of evidence that in many cases, that is how nature works.

The European: This seems to contradict the general trend to drive technological innovation by packing more computational power into a single computer chip. 

Wolfram: A couple of points. There is a phenomenon which I call computational irreducibility. When you have a process where the behavior is quite simple – like a planet orbiting around a star – we are smart enough to use math to figure out what will happen in the future without having to wait for the planet to move around. We can compute the outcome by plugging the right numbers into a formula. But many systems are irreducible after a number of steps – you really have to simulate each step to see what will happen. We need a lot of computational effort for that. But it’s a fallacy to believe that our current technology is the only possible computational technology. The fact is, we can make computers from a lot of materials, not just transistors. The reason that’s exciting is because it opens up the possibility of making a computer out of molecules. It hasn’t been done yet, and there’s a lot of ambient technology that is required to make a molecular computer possible. But it reminds us that we must not shrink transistors – we can use much simpler components.”