Not totally related but here's a fun thing to think about:<p>In Greg Egan's "Permutation City", an alternative set of physical rules is devised that is designed to produce a universe resembling ours, but that is computationally feasible to accurately simulate. This simulated universe is named the Autoverse.<p>The protagonist spends her time manipulating molecules in Autoverse simulations, trying to invent Autoverse equivalents to biochemical systems that will eventually lead to evolution.<p>As sci-fi "ideas" go, the Autoverse is pretty fucking awesome. Egan then takes the idea and pushes it into insanely fun territory. It's a great read (and actually I'm pretty sure I found out about it through HN).