Re: tech: digital physics

Eugene Leitl (
Tue, 11 May 1999 12:24:22 -0700 (PDT)

Anders Sandberg writes:

> No. But what was the issue here was the fact that the geometry of the
> underlying grid of the CA makes the physics in the CA nonisotropic -
> there are preferred directions where the speed of light is
> different. For example, in Game of Life information from an event at
> (0,0) at time zero will arrive to (100,100) at the same time as
> information from time zero events at all points (x,0) where 0<=x<=200.
> Clearly, this doesn't correspond well to our physics.

A number of cellular automata show isotropic wave propagation. Artifacts of lattice anisotropy do not necessary propagate to macro level. Otherwise, lattice type has a large impact. Some things work in cubic primitive lattice, some need hcp.