Jacques Bailhache, <[EMAIL PROTECTED]>, writes: > Is it really a fundamental difference between static and dynamic structures > ? > Any machine can be represented by a string. A program can be considered > either as a static character string, or as the description of the rules of > evolution of a dynamic process.
I am uncomfortable with saying that a process is equivalent to the rules which generate it. It seems to suggest that writing down the rules is equivalent to actually working out all the ramifications of those rules. It is true that the rules uniquely specify the process, but in practice it still takes work to find out exactly what the details of that process are. In particular, if the process in question is a consciousness-containing universe, what is actually necessary in order for that consciousness to exist? Running the program seems good enough to me. Is just writing the program enough? Hans Moravec takes the view that you don't even have to write the program; the mere fact that such a program potentially exists automatically means that the consciousness exists (and is, in fact, how and why our own consciousness-containing universe exists). I prefer a simpler approach to the string-process question. I would say that a "dynamic" three-dimensional process can be represented by a "static" four-dimensional space-time structure. This is the standard viewpoint for relativity theory. Time is just another dimension (albeit one with different properties than the spatial dimensions). Another way to think of this is to imagine a two-dimensional world. It's been demonstrated that you could, in theory, have a two-dimensional universal computer. Then any process operating in that computer could be represented as a three dimensional structure, where we use the third dimension to represent time. This solid, static three-dimensional structure then can encode any computational process. Some versions of the many-worlds model consider the universe to be branching at each point into multiple universes. This is harder to capture in a static picture. You can do it but it doesn't seem as natural. However another way to view this model is to have, instead of a single universe which branches into many, many initially identical universes which then differentiate themselves. These are equivalent ways of looking at the same phenomenon. With the differentiating-universes model we again have a simple flow of time within each universe and a very simple representation of processes in that universe as static structures. Hal
