Here’s an interesting fact: apparently, chemical self-reproduction is easier to achieve in gases than in liquids. This leads me to an interesting idea: maybe the very first steps in the origins of life took place not in the oceans but in the atmosphere. The mechanisms by which molecules can produce more of themselves are interesting, and in this post I’ll explore a bit about how such molecular reproduction (or, to use the technical term, autocatalysis) works.
What is life? Some people will say it’s obvious: life is reproduction. But I may never choose to reproduce, and a worker ant couldn’t if it wanted to – does that make us dead?
Others will say life is evolution. But on closer inspection, that doesn’t really stand up either. Evolution is easy enough to implement on a computer. You just store a bunch of random bit strings in memory, evaluate them according to some “fitness function”, and then “mutate” and “recombine” the best ones to produce a new generation. By iterating this process you get what’s called a “genetic algorithm”, and this can be used to design robot controllers and all sorts of other things. These things evolve, but are they alive? Some might say yes, but anyone with any experience in genetic algorithms will say no.
The relationship between probability and information is interesting and fun. The table below is a work in progress, but I think it’s kind of cool already. The idea is to compare information quantities with the probabilities of unlikely events. For instance, if I flipped a coin for every bit on my hard drive and they all came up heads, it would be pretty unlikely. But what else would be that improbable?