The idea that there is some special “now” that moves from moment to moment is a confused one, which leads to various paradoxes. But I have already presented those arguments. Instead I will show here that even if the universe really did have such a special “now” there would be no reason to believe in it. But it is this belief that motivates arguing for that special “now” to begin with, thus showing that even if the theory were true it would be unmotivated by experience, which is another way of arguing against it.
There are two models of time that the belief in the “now” can fit into. One holds that only a single moment exists, the “now” and that the future and past do not. The other is that the future and past exist, but that somehow a single moment is picked out as the “now”, and that over time different moments are picked out (like a movie projector showing different frames in sequence). I make this distinction only to make a preliminary argument about one variety of the first view, the variety that holds that since the past and future do not exist there are no facts about them. When you think about what it would imply it is obvious that no one truly subscribes to it. For example, someone who held this view would say that it is neither true nor false that Wednesday the 10th comes before Friday the 12th. This must make planning their schedule difficult. Similarly they must have failed history class, since they would maintain that it is not the case that Napoleon was defeated at Waterloo. Clearly this is ridiculous, and does not need to be considered further.
Therefore I will assume we agree that there are certain definite facts about at least past moments (there are some who will assert that facts about the future are of an indefinite nature since the future doesn’t exist yet, and it is not necessary to argue against that view for my purposes here). But if this is the case then every person, at every moment of time (both past moments and “now”) believes that it currently is “now” (or at least it is a fact that they believe it to be “now”). Since the moving “now” changes only the fact that a certain moment is “now”, and not any of the physical facts, people in past moments will obviously retain their attitudes as to whether or not it is “now” unchanged. And thus we can ask the question: “given my belief that it is ‘now’ how likely that it is actually ‘now’?”, and the answer is that the probability is pretty low. Given how many past moments there are it is far more likely that you are in one of them. The logical conclusion then is to accept that my strong belief that it is “now” is misguided, and that probably some other moment is selected as “now”.
And this line of thought reveals that even if the moving now was in the unimaginably distant future, or absent altogether, the facts would remain the same. I would still be typing this paragraph. I would still treat my experiences as though they occurred in some universally special moment. Nothing would change. So why then believe that the “now” exists at all, since there is no factual difference, that we can detect, between a universe with a “now” and a universe without one? The only reason people do insist on such a “now” is because of their strong intuition that they are in it, but we have shown that the intuition is baseless, and so there is no good reason to believe in a “now”. Of course this doesn’t make the idea of a special present moment any less intuitive, but our intuitions are not infallible, and they have been proven to be wrong often enough in the past.