I heard Janna Levin yesterday on Speaking of Faith on NPR talking about her novel A Madman Dreams of Turing Machines. Ms. Levin is a physicist, and the novel discusses the lives of Alan Turing and Kurt Gödel. It sounds like an interesting book.
Predictably, the host Krista Tippett used Gödel’s incompleteness theorems to support her case for faith — that there is more to the universe than can be understood by poor man’s understanding, but that’s a topic for when I have more time.
Another topic that caught my attention was the discussion of free will. Ms. Levin and Ms. Tippett danced all around the question of whether we have free will or not, and what the ramifications are if we don’t. It seems to me that this is pretty straightforward.
Suppose you have two identical closed boxes and within them set up a number of molecules in exactly the same arrangement: position and velocity. Yes I know this is impossible as far as we know, but this is a thought experiment, anything is possible. Unless there is something mystical going on (which I don’t take as a serious option) there are two possibilities:
- The two boxes will remain identical as the molecules go about their business.
- Some randomizing factor — quantum or otherwise — will cause the boxes to fall out of sync.
First, I would argue that in the second case it might be you didn’t do a good enough job of meeting the initial conditions. I find it hard to comprehend something truly random, given enough detail in the initial setup. It may be that there is no way to run such an experiment in real life.
But that’s irrelevant. In either case, there is no free will, even if the “number of molecules” is a human being or two, and one of the “boxes” is the universe. It’s just not there. That said, consider a video game like Mario Kart. The artificial intelligences in the game can give the impression of novel behavior, of “free will.” Depending on the game (I have no experience with Mario Kart) the illusion can be more or less convincing, often depending on the complexity of the algorithms used to generate the artificial intelligence.
Scale that up to human beings and the “simulation” becomes so complex, the illusion of free will so convincing, that to try to find the limits of it is seemingly futile. A human being cannot be predicted.
With today’s technology, anyway.