Why Does Time Pass ?

According to the moving spotlight theory of time, the property of being presentmoves from earlier times to later times, like a spotlight shone on spacetime by God.In more detail, the theory has three components. First, it is a version of eternalism:all times, past present and future, exist. (Here I use “exist” in its tenseless sense.)Second, it is a version of the A-theory of time: there are non-relative facts aboutwhich times are past, which time is present, and which times are future. That is,it is not just that the year 1066 is past relative to 2007. The year 1066 is also pastfull-stop, not relative to any other time. (The A-theory is opposed to the B-theoryof time, which says that facts about which times are past obtain only relative toother times.) And third, on this view the passage of time is a real phenomenon.Which moment is present keeps changing. As I will sometimes put it, the NOWmoves from the past toward the future. And this does not mean that relative todi erent times, di erent times are present. Even the B-theory can say that 1999 ispresent relative to 1999 but is not present relative to 2007. No, according to themoving spotlight theory, the claim that which moment is present keeps changing issupposed to be true, even from a perspective outside time.My main goal in this paper is to present a new version of the moving spotlighttheory (though in some respects the theory I present also resembles the growingblock universe theory of time). This version makes a connection between thepassage of time (the motion of the NOW) and change. In fact, it uses facts aboutchange to explain facts about the passage of time. The bulk of the paper is devotedto describing, in detail, how the theory works. I also believe that my new versionhas advantages over the standard version. It explains things that the standard versioncannot explain. It explains both why the NOW moves, and why it moves at aconstant rate. I will discuss why I think these are advantages in the final section