Evanescence

Compare two worlds:

• Evanescent World (EW): There is a rich three-dimensional reality that exists for only one moment of time.

• Timeless World (TW): There is a rich timeless three-dimensional reality.

Intuitively, EW is, well, evanescent, while TW is “permanent”.

On a B-theory of time, it is difficult to make sense of any such difference in evanescence between EW and TW. But a staunch B-theorist will say that this is a feature, not a bug.

However, an A-theorist will, I think, want to distinguish EW from TW. But it is difficult to do so.

Start with a moving spotlight theory. The difference between TW and EW seems to be that in EW we have time’s spotlight, and in Timeless we don’t. But time’s spotlight in EW is always (i.e., at all times, of which there is only one) lighting all of the three-dimensional reality. The spotlight is no more evanescent than the rest of the reality, and so adding the spotlight does not seem to make the Evanescent world be really evanescent.

Now, consider any of the three major A-theories: moving spotlight, presentism and growing block. At the one and only moment of time in EW, one could say (if one could speak in one moment):

1. It is not the case that there will be anything

2. It is not the case that there was anything.

But one could say the very same thing in TW (if one could speak timelessly, which is no harder than speaking in one moment). And in neither EW nor in TW can one say things like:

3. Reality will vanish.

For “will” cannot reach beyond time.

What can the A-theorist do? I think they can do only thing: They can say that EW is evanescent precisely because:

4. In EW there is exactly one moment of time.

But this is something that the B-theorist can say as well. In other words, the alleged dynamism of time on the A-theory does not seem to do anything to help explain why EW is evanescent.

So what? Well, if the A-theory explains anything better than the B-theory does, it better explains more ordinary evanescence, such as the evanescence of our lives—things flow out of existence with time, or something like that. But now take the limit case of ordinary evanescence: an entity that exists for only one moment, in a world like ours which begins long before the entity and ends long after it. And notice that the entity that exists for one moment of time in a world like ours is no more evanescent than every entity in EW. Thus there is something wrong with an A-theoretic explanation for evanescence that applies to the entity in a world like ours but not to all the entities of EW—it fails to really get at what evanescence is.

But if the A-theory really doesn’t explain evanescence better than the B-theory does, then I suspect it fails to be the better alternative.