Are the realms different dimensions or different planets?

Question

Thor's mortal muse (I forget the name) says to Darcy: "An Einstein-Rosen Bridge is a theoretical connection between two different points of space-time. lt's a wormhole."

But the S.H.I.E.L.D director, at the end of the movie, says to Dr. Selvig: "Your work has impressed a lot of people who are much smarter than l am. The Foster Theory. A gateway to another dimension. lt's unprecedented."

I thought wormholes transported you to different points in our own dimension? And the Bifrost animations looked a lot like they were travelling between planets.

Unfortunately, I know nothing about the Einsten-Rosen bridge, so I do not understand. Are the different "-gards" in different locations of our universe, or different dimensions?

Answer 1

I think the SHIELD operative should have said "A gateway through another dimension".

From wikipedia:

For a simple visual explanation of a wormhole, consider spacetime visualized as a two-dimensional (2D) surface. If this surface is folded along a third dimension, it allows one to picture a wormhole "bridge".

So taking the example above up a dimension the Bifrost bridges two 3 Dimensional locations in space via a 4th dimension.

The different realms are merely locations in space.

Answer 2

The realms must be different locations in the same dimension. Otherwise Heimdall wouldn't be able to see them with his amazing sight. As mentioned in the movie, the Einstein-Rosen bridge is a wormhole. A wormhole connects two locations via a conduit that goes through other dimensions. This is what the Bifrost is, a wormhole device.

This is confirmed in the commentary on Thor: The Dark World. When Thor and Malekith are bouncing between worlds, and Mjolnir tries to go from Earth to Svartalfheim, they refer to it in the commentary as Mjolnir trying to take the long way through normal space. This means it's possible to just go through normal space to traverse realms.