Speaking for myself, I "look out on the world" from the "perspective" of just one time. But it is hard to see how this fact can be reconciled with the block universe theory. For that theory says that I exist at many times, times that make up a decades-long stretch of time. So what could make it true that I "look out on the world" from the perspective of only one of those times? It doesn't look like the block universe theory can answer this question. The moving spotlight theory, on the other hand, seems to provide an answer. That theory can say that I look out on the world from just this time because this time is the one that is objectively present.

That is a quick and dirty presentation of the argument. We need a statement of the argument that doesn't lean so hard on talk of "looking out on the world" from the "perspective" of a time. Here is a way to run the argument without them. It comes in two parts.

Supposing this is true, why is it true? It is hard to see how to answer this question if the block universe theory is true. According to that theory I am related to the red experiences and the white experiences in the same way. I have the red experiences at some time or other; the same goes for the white ones. So the theory cannot explain why only the red experiences are available to me by pointing to some difference between the way I am related to them and the way I am related to the white experiences.

The theory could in principle explain why only the red experiences are available by pointing to a difference in the experiences themselves. But what could the relevant difference be? True, the red experiences are experiences of red things and the white ones are not. But that cannot be why it is only the red ones that are available to me.

The theory's failure to explain why only the red experiences are available suggests that, if the theory is true, it is false that only the red experiences are available to me. Which is absurd.

The moving spotlight theory, on the other hand, can explain why only the red experiences are available to me. The spotlight of intrinsic privilege shines on the red experiences but not the white ones. The theory may draw a connection between being present and being available. It may say that the experiences of mine that are available to me, or presented to me, are all and only the ones that are present.

That's stage 1. Stage 1 aims to establish that exactly one time is present. But we also need some reason to believe that which time is present changes. The argument has a second stage that purports to do this.

Stage 2. Which experiences are available to me has been changing. Not only are the red experiences available to me, but, as I remember, the white experiences were available to me. Now suppose that stage one of the argument has been successful. The experiences available to me are the ones that are present. Then it follows that while Tuesday and things that happen on Tuesday are present, Monday and things that happened on Monday were present. But then which time is present has changed. Time has passed.