From: Joscha Bach Sent: Monday, August 1, 2016 3:57 PM To: Jeffrey Epstein Subject: Re: conjecture, probability is a =orce. </=iv> I do not understand =orces as primitives, or atomic properties. How do you envision =t? I imagine the universe as a =aurally closed machine that can be described on a lowest level with a =et of simple, uniform rules. The primary data structure can be a =ypergraph, i.e. a set of locations that are connected with shared, =yped properties. All changes in the universe can be described using =raph rewriting rules. The =ules could in principle either be deterministic, like in a cellular =utomaton, or probabilistic, like in a Markov model. However, our =niverse seems to preserve the amount of information in it, as suggested =y the first law of thermodynamics, which makes it likely that all =ransitions are reversible (i.e. each state has exactly one preceding =tate; if a state had two or more possible precedents, we would =ffectively delete bits). The most elegant universe seems to be =eterministic, with all probabilistic effects at the lowest level being =seudorandom (many cellular automata have that property). A =robabilistic universe seems possible, too, but I do not understand the =oops I would have to make it jump through so it gives rise to the =pparent preservation of information. The universe contains hierarchies of causal =ystems. A causal system is one that can be described independently of =he underlying dynamics, as long as those remain within certain bounds. =or example, I can talk about tomorrow's weather, unless the planet is =eing hit by an asteroid, I can talk about the program running on my =omputer, unless the processor overheats or the power runs =ut. Causal systems require that I =an identify conditional state transitions, and there are mechanisms =cting on the underlying dynamics the constrain the state =pace. As soon as we leave the =lementary level of the universe and look at a higher causal le