Chapter 9: Fundamental Physics

Section 5: Ultimate Models for the Universe

Initial conditions [for the universe]

To find the behavior of the universe one potentially needs to know not only its rule but also its initial conditions. Like the rule, I suspect that the initial conditions will turn out to be simple. And ultimately there should be traces of such simplicity in, say, the distribution of galaxies or the cosmic microwave background. But ideas like those on page 1055—as well as inflation—tend to suggest that we currently see only a tiny fraction of the whole universe, making it very difficult for example to recognize overall geometrical regularities. And it could also be that even though there might ultimately have been simple initial conditions, the current phase of our universe might be the result of some sequence of previous phases, and so effectively have much more complicated initial conditions. (Proposals discussed in quantum cosmology since the 1980s that for example just involve requiring the universe to satisfy final but not initial boundary condition constraints do not fit well into my kinds of models.)

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From Stephen Wolfram: A New Kind of Science [citation]