# Progressive Summary ## Defintions ergodic - the system visits all its possible states over some “reasonable” time period # Structured Notes ### Chapter 1 - The World Is Not a Machine > Since the triumphs of Descartes, Newton, and Laplace and the birth of classical physics, we have come to regard physics as the answer to our questions about what reality “is.” In that search, we have come to think of the world as a vast machine. This Newtonian fundamental framework is wonderfully extended by Special and General Relativity. Quantum Mechanics, and Quantum Field Theory, alter some of the basic deterministic aspects of classical physics but not the view of reality as an enormous “machine.” > Has the universe made all the possible types of stable atoms? Yes. Bosons and fermions—the two broad kinds of particles physics knows—have glommed together in every conceivable combination to yield the hundred-odd elements that make matter. But will the universe make all possible complex things? No, not at all. Most complex things will never get to exist at all. > History enters when the space of the possible is vastly larger than what can become actual. For example, the evolution of life itself is a profoundly historical process. So too may be space chemistry and the formation of complex molecules. Thus, the becoming of the universe above the level of atoms is a historical process. > The physicist’s phrase for this historicity is “nonergodic.” “Ergodic” means, roughly, that the system visits all its possible states over some “reasonable” time period. The central example, from equilibrium statistical mechanics, is a liter volume of gas falling to equilibrium rapidly. The gas particles darting about in the bottle assume nearly every possible configuration before settling into the stablest possible state. But “nonergodic” means that a system does not visit all its possible states, like the amino acids that cannot make all possible proteins even after an astronomical number of repetitions of the 13.7-billion-year history of the universe. > If we ask whether the universe has created all stable atoms, the answer is yes. So the universe is roughly ergodic with respect to atoms, but it is not ergodic with respect to complex molecules. > Consider proteins of length N = 1,2,3,4, . . . N + 1 amino acids. As N increases, the universe samples the possible sequences ever more sparsely. The universe can explore and surge upward in complexity indefinitely. In this sense, there is an indefinite “sink” upward in complexity. The universe can explore indefinitely vast realms. # Quotes > Darwin taught that new species drive wedges into the crowded floor of nature to make room for their own existence: yes, but no. Creatures, by existing, create the very conditions for other creatures to come into existence. Species constitute the very cracks in the floor of nature that constitute the niches for yet new species to come into existence, creating yet more cracks for still more species to spring forth. > We think that in physics—Special and General Relativity, Quantum Mechanics and Quantum Field Theory with the Standard Model—we will find the foundations from which we can derive the world, the ultimate becoming. We cannot. The ultimate may rest on the foundations, but it is not derivable from them. This ultimate, an unknowable unfolding, slips its foundational moorings and floats free. As Heraclitus said, the World Bubbles Forth.