Interesting. I'll only entertain it further when I see something that suggests that the realms can even orbit something.
Well, Mannimarco orbits Arkay, eclipsing him once a week.
Except that we can actually see them in space. We can see Oblivion, but not each individual realm, a major reason why I think the way I do about the subject.
Extrasolar planets cannot be seen from space, even with powerful telescopes.
The CS tends to abstract a few things for a quick reference point. I'm talking In-game with my sun thing.
In-game, there's no difference.
More on topic, what about Nocturnal? We haven't seen her realm and by all accounts she claims domain over the void itself. That would weaken the Daedric planes are planets theory.
So she doesn't claim domain over an actual body but the void itself, she can do that I suppose.
That doesn't make sense. Sure, you can think of an overlaying system I can agree with you on that. Though in this system, regular physics are still an exception. As exemplified above, they only occurs in place where there are forces that want it to be. Of course you can hold that myth and magic break the rules everywhere, except in those places were they're consciously held back. If you're consistent about it that works as well.
But we have no proof that physics only occur when the forces want it to be. And they're strangely identical, in the planes of Mehrunes Dagon, Jyggalag, Peryite, Boethiah, Lorkhan, and possibly Mankar Camoran.
But that only brings us back to the original argument. Infinite plane(t)s, in impossible orbits and holes to Aetherius being observed as planets and stars due to Mortal Mental stress aren't impossible as outside of Nirn nothing enforces normality.
As such there is no reason to peg the cosmology as implausible.
And there is no reason to peg an alternate observation-based theory as implausible.
To the contrary, myth appears to be shaping everything. But that's another discussion.
We're obviously on different pages. I see myth as only shaping the mortal plane because it is where the Convention took place, and where the Divines gave themselves up. I do, however, sometimes wonder if Jyggalag did some sort of Lorkhan-type creation.
As already shown, the Empire has a fairly advanced knowledge of what things are like outside Mundus. The only mythology referenced by the Cosmology is common knowledge and can be considered accurate as the gods involved exist.
As such there is no reason to peg the cosmology as the result of ignorance.
Their knowledge, however, is not a work of astronomy, but of magic, opening portals to bridge seemingly endless gaps between our plane and others. Of astronomical knowledge itself, they have shown to have little.
What's missing from this discussion is any sort of research material and an ability to check for ourselves. But we're not talking about a real world, we're talking about a fantasy universe. This means that you need to give the author(s) a certain amount of trust and when there is no obvious contradiction, assume that what he tells you is indeed true.
My ideas are gathered from studying texts on Oblivion as well as observing the planes of Oblivion themselves (including Mundus), looking at their skies and the laws of physics that they go by. I tend to take the words of those from Oblivion, as they tend to have a clearer view of the bigger picture, even if they may possess some mental abnormalities.