Asgard

In Norse mythology, Asgard (Old Norse: Ásgarðr; meaning "Enclosure of the Æsir") is a small otherdimentional planetary body, whose nature and physics are different from those of planetary bodies in the Earthly dimension. Asgard is not a sphere like the Earth of Moon, but a relatively flat asteroid-like landmass suspended in space. Asgard does not rotate about its axis, nor does it revolve around a sun. Asgard has intervals of night and day (of undisclosed durations) even though it does not rotate. There is no evidence of changing seasons, however. It is not known if Asgard's source of light and heat is the Earth's sun, a sun in the Asgardian dimension whose gravity does not exert itself on Asgard, or a glowing ball of light dissimilar to a star in most of its properties. Unlike Earth, Where the force of gravitation radiates from the centre of the sphere, Asgard's gravity apparently radiates from some point or object beneath the suspended landmass. Consequently, there is a top side to Asgard, upon which beings can stand, and a bottom side where beings cannot stand and from which they will fall through space toward the source of gravitation. At the boundaries of Asgard's landmass, a being or object can step off into the void.

There is apparently some force that keeps the bottom and edges of Asgard's landmass from eroding away. Whatever this force is also prevent the bodies of water which are at certain of Asgard's boundaries from pouring off into the void, as well as preventing Asgard's atmosphere from escaping. While the gravity of Asgard is roughly analogous to Earth's, common matter is considerably denser on an average. Consequently a chair made of Asdardian wood would be more massive (and heavier) than a chair made of analogous Earthly wood. Rocks, water, flesh, bone, steel - all matter is denser and thus more durable. Besides all of the anomalies described above, Asgard is connected in some as yet unknown way with at least two other dimensional planes, one of which is that of the Earth (whom the Asgardians call Midgard, a word meaning "Middle Realm").

Yggdrasil is an immense tree that is central in Norse cosmology. It was said to be the world tree around which the nine worlds existed. Hvergelmir (Old Norse "bubbling boiling spring") is the wellspring of cold in Niflheim in Norse mythology. All cold rivers are said to come from here, and it was said to be the source of the eleven rivers, Élivágar. Above the spring, the serpent Níðhöggr gnaws on one of the roots of the world tree, Yggdrasil. The Asgardians refer to all of the major known inhabited realms of their cosmology as the "Nine Worlds." Only four of the Nine Worlds are located on the main Asgardian landmass: Asgard; home of the Gods, Vanahelm; home of the Asgardians' sister race, the Vanir, Nidavellir; home of the Dwarves, and Alfheim; home of the Light Elves.

The remainder of the Nine Worlds are on separated landmass isolated from one another by interdimensional space. Midgard, our Earth, does not appear to be physically affected by the motions of any of the other physical bodies in the Asgardian cosmology, although Earth's axis (the imaginary pole around which it rotates) is in alignment with one of the roots of Yggdrasil, the cosmic ash tree that stands in Asgard. Jotunheim, the world of the giants, is a flat ring-shaped realm with high mountains along its inner edge. It is apparently on its own separate dimension plain, discrete from Asgard's and Earths, home of the Dark Elves, is another asteroid-like land-mass, smaller than Asgard. There are numerous nexus-portals between the mountains of Jotunheim and Svartalfheim and the mountains of Asgard permitting easy passage by denizens of each realm. These passageways make Jotunheim and Svartalfheim seem like "underworlds" of the Asgardian continent itself.

The eighth of the Nine Worlds is Helheim, realm of the dead, and its sister realm, Niffleheim. In the Asgardian scheme of afterlife, the heroes and honored dead go to Valhalla, a special region of Asgard, the common dead go to Hel, and the dishonoured dead (murderers and other evildoers) go to Nefflehelm, and Valhalla possess the necessary physical conditions to permit the astral form of the deceased to exist there for indefinite periods of time. The ninth of the Nine Worlds is Muspelheim, land of the fiery demons. Muspelheim is on its own dimension plane, separate from from all the other Nine Worlds. In the Asgardians' account of the origin of their cosmology, Muspelheim, the land of fire, and Nifleheim, the land of ice, were said to predate recorded time, separated from one another by Ginnungagap, the Yawning Void.

Asgard is honeycombed with nexus-portals to the various extradimensional realms or the Nine Worlds, making the worlds (with the exception of Earth) sometimes seem like they are on a contiguous plain (indeed early cartographers of Asgard mapped it this way). Another unique feature of Asgard is the Cave of Time, an apparently natural phenomenon through which passage to other time eras is possible.

There are several singular creatures who exist upon various of the Nine Worlds. The first is the Midgard Serpent Jormungand, an immense snake-like dragon whose bodyencircles the inner edge of the mountains of Jotunheim closest to Midgard. The Midgard Serpent lies at the very edge of the dimensional boundry between Jotunheim and Midgard, and prevents passage between dimensions. The second is the winged dragon Nidhogg, who lives in Niffleheim and gnaws at one of the roos Yggdrasil. The third is the giant wolf-god Fenris, who is responcible for the war-god Tyr's loss of a hand. Fenris is imprisoned in the disant land of Varinheim. The fourth creature is the primordial ice giant Ymir.