" The whole, entire universe is quantum mechanical. And here's where it gets really freaky. If there's a dead-cat world and an alive-cat world, this has implications for the observer, too, because the observer exists within the quantum system." (Ozeki, p. 398)

          This theory of time, popularly known as the "many worlds" or "multiverse" theory starts out as a fun concept, until you dwell a bit deeper on the thought. Quickly, the particulars of this theory get staggering. According to quantum mechanics, every possible outcome of every situation which could theoretically yield different outcomes exists and is perpetuated in a new offshoot timeline.

           Consider this scenario; you and six of your closest friends decide to draw lots for who will pick the dinner that evening, every person rolls the six sided die once, with the person who rolls a six getting to chose the meal. For every person there are six possibilities, so just in this very small, simple example quickly there are a panoply of possibilities, all of which are perpetuated in their own quantum system in which different variations of you exist. It ends up sort of resembling inverted tree roots, with one starting point expanding and spreading to an enormous scale.

          Then, when you consider how many times during the course of the day that you make small, seemingly innocuous decisions, and all of the possible different decisions and outcomes and all the different decisions and outcomes in these newly conceived systems and before long the numbers get into territory that, when spelled out the numbers wouldn't fit all on the same line.

          Things get even more dizzying when the situations that all the versions of you in all the systems could conceivably encounter and experience. The limitations exist only within the imagination of the beholder. Quite probably, there are many systems in which you met an untimely death, with every new system providing a new mortal instrument, and, in another probably quite large set of systems and number of fantastic fates have befallen you.

         In a way, this could be exactly what old Jiko was trying to get across to Nao; existence is inherently infinite in possibility and unavoidably finite in terms of time so the best policy in such a multiverse is to try and propagate as much good as one can muster across the systems.