My favorite (completely unsupported by data) speculation on space-time is as a 4-D crystal (the past) with dislocations (the particles) and a phase boundary (the present). Dislocations cannot be individually repaired, but only by pair creation or annihilation, just like particles. The idea is that there is a meta-time in which crystallization happens at the phase boundary. Net growth of the crystal corresponds to observable time. The advancement in meta-time allows for alternative futures to be investigated by growth and retraction of the phase boundary -- note the very close relationship between stat mech and Wigner rotation in QFT. Regular lattices with defects have curvature, so "gravitation" happens automatically in this speculation. I'd like to see an enumeration of the types of defects that can occur in a regular 4-D lattice. Of course, Kaluza-Klein models might make higher dimensional lattices a possibility here as well. On Jun 30, 2010, at 1:00 PM, Mike Stay wrote:
Gravitons are presumed to change the shape of spacetime, and if there are enough of them, perhaps even its topology. Does anyone on the list know of any cellular automata that, say, change the neighborhood based on the density or topology of clumps of "on" cells, or similar? -- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun