Gappy Objects

Consider an apple. I assume we all agree that it counts as an object. Now consider the mereological sum of that apple plus the northern hemisphere of Mars. Is this fusion also an object? It may not be one we'd have any reason to use, but I can't think of any, er... objective... grounds to deny it 'object' status. One might suggest that an object must be spatially continuous. But if that were so, then physics tells us there exist no such objects above the sub-atomic level. Besides, the territory of the United States (including Alaska) is clearly 'gappy' in a similar way, yet we have no objection to calling that particular sum a single object. So, it seems to me, any objection to recognising 'gappy' objects like my apple-Mars fusion is merely pragmatic, rather than metaphysical. That is, the object does exist, but we usually wouldn't bother saying so.

But is it an object in exactly the same way? Or are there different degrees of 'objectness'? Here I'm wondering if the common-sense objects we recognise every day (e.g. apples, chairs, etc.) share some metaphysical property which sets them apart from more bizarre objects like the apple-Mars sum. For example, we tend to recognise as a single object clumps of matter that exhibit unified behaviour (if I push part of an apple, the whole thing moves, but Mars does not move with it). But, as before, we could always find exceptions. Further, it seems to me that there could be no objective reason to ontologically privilege some collection of atoms over any other. So I think the difference is purely pragmatic, but I'd be interested to hear others' thoughts here.

Things get even crazier once we admit the eternalist conception of time as a sort of 'fourth dimension'. For then objects do not 'persist' through time in the intuitive sense of wholly existing at each moment. Instead, the whole object is a space-time 'worm': a combination of temporal parts.

But then, we ask, what privileges that particular combination of parts over any other? Is there any reason why we couldn't make another bizarre mix of objects? Consider, say, the sum of {me today + my cat tomorrow}. Can we call this mix a single object? Again, it's a pretty useless one, but I can't think of any principled objection to it.

However, these sorts of mixes seem quite different in kind to a normal object like a temporally-extended apple. It's not merely practical for us to say it's the same apple now as it was a second ago. Rather, there seems a genuine metaphysical connection between the temporal parts. We might say they are parts of a natural object, whereas "my cat tomorrow" is part of the contrived me-cat pseudo-object. Is there any way to account for this, without adopting a presentist view of time?

I find a certain theoretical elegance to the unrestrained eternalist picture which allows for doubly-gappy (i.e. discontinuous in both space and time) objects. It's very simple, after all. We imagine the entire space-time 'loaf' of the universe at all moments, then we say that every portion (or combination of portions) of the loaf counts as a metaphysical 'object'. Pick and choose whatever you want, and you get an object. The extreme generality is almost beautiful.

The only problem is that it doesn't make sense. It suggests that {me now + my cat tomorrow} is just as much a single unified object as {me now + me tomorrow} is. And that's just absurd. There's clearly a difference between the metaphysical status of these two objects.

I can accept arbitrary spatially-gappy objects as metaphysically equivalent to any other object, and happily dismiss our common-sense views as mere pragmatism, but I cannot do the same across time. I think there must be some objective relation between various temporal parts such that some are more appropriately combined than others.

My question is: Can we make sense of this within eternalism?