Well, michael, I could imagine that being a domain of Knowledge (Wizardry), Magic (Wizardry) or perhaps "Force" (telekinesis). In the latter case, we'd view it perhaps as 'gravity' in our enlightened state as players. But power over gravity would surely seem magical in the Afterworld and sufficiently significant power would definitely appear godly.
WarDomo: the way I read it (and others please chime in if you feel more detail is helpful or think it means something different!) is that the dominion impacts some of what you do at higher tiers and it helps provide additional descriptor-like color to your character. E.g. You probably wouldn't pick a God of Fire who has the focus "wears a sheen of ice". The book specifically says:
"Ironically, a PC's initial choice of dominion is the most telling thing about them, while at the same time being the most ephemeral, especially as their dominion relates to game mechanics. The PC's chosen dominion informs their dogma (their tier 3 Obligation Ed. Note: I think they mean tier 4), informs the dominion benefits they choose (starting at second tier), and even more important, might guide them when they decide their type,focus, and descriptor."
It goes on to say...
"A character's dominion is a journey, not a destination. Selecting it means it's where the PC would like to take their character eventually, but it might not be where they end up. For example, they might begin thinking they're a god of Travel, but end up being a god of Lost Causes."
It goes on to identify that there's no one parcelling out dominions in the firmament, so you can change your mind as you progress/play and as things happen to your character. Imagine, for example, your character being healed of his hideousness and perhaps shown some other path or given some other opportunity -- he could become a god of healing. Or he could prefer the cleansing qualities of a good godly fire and migrate to be the God of Fire. etc. etc.
Short version - mechanically, I think a Dominion is mostly flavor. You'll use it to craft your story, embellish your divine abilities (e.g. Your nimbus might be specific to your dominion), and to guide you on the campaign choices you make. A god of War isn't like to try and fulfill a prophecy of love, as an example.
Does that help?
