8. DM and RUCA

We must carefully distinguish the RUCA from DM, the informational process that may be run­ning in the. RUCA. This is similar to distinguish­ing a chess board, the chess men and a book of the rules from a game of chess. One is the physi­cal representation of the state of the system and of the rules; the other is an informational process that is identically the same whether it takes place on a real chess board or in a computer memory. For each RUCA, there are one or more such in­formational processes. DM is simply an informa­tional process that runs on a RUCA and that in one way or another should be able to model na­ture. Our common sense world (intuitive physics) and RUCA share certain properties in common: they are both universal, locally Euclidian, locally connected, partially described by small integers and deterministic. In common with modern theo­retical physics, RUCA are microscopically revers­ible, have certain symmetries and conserved quan­tities. In other ways RUCA seem very different than current concepts of theoretical physics, they are: globally Cartesian, simply deterministic, non-isotropic, have a fixed reference frame and are dis­crete in all regards.

Nature and DM have many more things in com­mon than physics and RUCA, in that DM can be relativistically correct [16], apparently non-deterministic [17], asymptotically isotropic [18], perform as though there is no fixed reference frame, model apparently continuous phenomena with great or perfect accuracy, produce a stable of particles as easily as Conway's Game of Life produces gliders, puffer engines, and other stable Life forms. We will show that DM systems with a local rule nevertheless have the property that the state of a cell at a particular time can be, in an un­usual way, functionally related to the state of dis­tant cells that are outside the conventional light cone of physics. This makes us optimistic about the possibility that DM may be capable of using mechanistic, deterministic and local rules as a substrate and yet produce behavior that obeys the laws of QM. In short, we cannot find good reason to believe that DM is incapable of manifesting all phenomena associated with fundamental particles and processes in physics.

[16]  T. Toffoli, Four topics in lattice gases: ergodicity; rela­tivity; information flow; and rule compression for par­allel lattice-gas machines, in: Discrete Kinetic Theory, Lattice Gas Dynamics and Foundations of Hydrody­namics, ed. R. Monaco (World Scientific, Singapore, 1989) pp.343-354.

[17]  5. Wolfram, Random-sequence generation by cellular automata, Adv. Appl. Math. 7 (1986) 123-169.

[18]  U. Irisch, B. Hasslacher and Y. Pomeau, Lattice-gas automata for the Navier-Stokes equation, Phys. Rev~ Lett. 56 (1986) 1505-1508.