Currently, most physicists believe that only a small fraction of all the matter and energy in the universe is visible and can be seen through our most powerful telescopes. The remaining majority of the universe is thought to consist of elusive dark matter and dark energy, two substances about which we know very little. This presentation will explore the evidence in supporting the dark matter and dark energy theories and discuss some of their implications for how our universe will evolve.
In order to predict the future state of a quantum system, we generally do not need to know the past state of the entire universe, but only the state of a finite neighborhood of the system. This locality is best expressed as a restriction on how information "flows" between systems. In this talk I will describe some recent work, inspired by quantum cellular automata, about the information strucutre of local quantum dynamics. Issues to be discussed include the definition of "locality", some characterization theorems, connections between classical and quantum locality for reversible maps, the relation between local and global dynamics, and the dissection of CNOT.