Board Thread:Questions and Answers/@comment-5157293-20131110013820/@comment-3317214-20131112082759

But I'm talking about the huge ship Malekith brought to Asgard. The largest thing we saw transported through these "blurs" before the convergence was Jane. Also, it seems very unlikely that Malekith would have found a portal similar to the one Jane found in the warehouse. And more unlikely that this portal would have taken them to Asgard, which is specifically where they wanted to go. But on top of that, I just think the ship would've been too big.

I guess I'm just theorising, but I think it's possible that the nine realms in the MCU all exist on the same plane, the same universe. Meaning that you can get to any of them by travelling through vast amounts of space. And that "realms" is just a term used to describe different planets that are connected through the Yggdrasil pathways.