Big Bang argument

Wolfram and others suggest a properly crafted cellular automaton could replicate the known mechanics of the universe — gravitational, electro-magnetic, strong, and weak forces — and provide a basis for a unified theory.

If the models start from a seed condition, then they also model a Big Bang which raises interesting questions:

1. The grid
1. What is the grid before the automaton runs?
2. Where does the grid come from?
3. What type of grid
1. Shapes of the cells?
2. What kind of information is embedded in the choice of grid/cell geometry?
2. Cells
1. What is the state of the cells before the automaton runs?
2. What is the state of the "passive" cell?
3. Rules
1. How many rules are required?
2. What is the size of the neighborhood?
3. Leading to:
1. How many possible universes?
2. Are these other universes valid, or just artifacts of the one model?