In Norse mythology, Bifrost (Old Norse: Bifröst) is the rainbow bridge that connects Asgard (home of the gods) with Midgard (home of mankind). The gods made the bridge themselves, and it has three colors. One of them is a burning fire that keeps the giants out of Asgard. The god Heimdall keeps watch over the bridge day and night. Even so, Bifrost will not survive Ragnarok.
Why Is the Rainbow Bridge on Fire?
The sources only name one of the three colors, and that is red (Old Norse: rauðr). The red in the rainbow is burning fire. Without it, the frost giants and the mountain giants could walk straight up into Asgard.
But the fire also causes trouble for one of the gods.
According to Snorri, the gods ride over Bifrost every day to hold court at the Well of Urd, under the world tree Yggdrasil. Thor is the only one who walks. The poem Grímnismál says that he wades through four rivers to get there, because the bridge is “ablaze with flames”.
If you think that sounds a bit strange, you are not the only one. The Well of Urd lies in the land of the gods, so why would they need a bridge to get there?
The poem itself only says that “the bridge of the gods” is burning. The scholar John Lindow points out that this may not be Bifrost at all, and that it may have been Snorri who connected the two.
The Guardian of Bifrost
The god Heimdall lives in his hall Himinbjörg at the end of Bifrost, and from there he guards the bridge against the mountain giants.
Heimdall was probably chosen for this job because of his senses. He can see a hundred leagues away, which is several hundred kilometers, and just as well at night as during the day. He also needs less sleep than a bird. His hearing is just as impressive. He can even hear the grass grow in the ground and the wool grow on a sheep.
Heimdall also has a horn called Gjallarhorn, which means “the yelling horn”. It is so loud that it can be heard in all the realms. At Ragnarok, Heimdall will blow it to warn the gods that the last battle is about to begin.
If a jötunn should be stupid enough to try to sneak into Asgard, Heimdall has his sword ready. But with Heimdall watching and the fire burning, it is very unlikely that a jötunn would even make it up the bridge.
In many modern books, Heimdall’s sword is called Hofund, and that is also the name Marvel uses for his sword in its Thor universe. But you will not find the name Hofund in the Eddas. It seems to come from the Old Norse word höfuð, which means “head”.
In Snorri’s text, the sword and the head are more of a riddle. A sword can be called “Heimdall’s head”, and a head can be called “Heimdall’s sword”. The scholar John Lindow admits that no one really understands why.
What Happens to Bifrost at Ragnarok?
At Ragnarok, the sky splits open. The fire giants, the sons of Muspell, ride out with Surtr in front. When they cross Bifrost, the bridge breaks under them.
According to Snorri, this is not because the gods built a poor bridge. Bifrost is strong, but nothing in this world can hold when the sons of Muspell attack.
The poem Fáfnismál tells it a little differently. There, the bridge breaks as the gods ride out to the last battle, and their horses have to swim.
What Does the Name Bifrost Mean?
No one knows for sure what the name Bifrost means. The name is spelled in two slightly different ways: “Bilröst” in the Poetic Edda and “Bifröst” in the Prose Edda.
In Old Norse, bifask means “to tremble”, and röst means “mile”, so Bifröst could be translated as “the trembling mile”. For Bilröst, the Norse language expert Dr. Jackson Crawford suggests “the blinking mile” or “the winking mile”.
Crawford explains that bil means “moment” or “failure”. He bases this on one of Odin’s names, Bileygr, which means “wavering-eyed” or “winking-eyed”.
Snorri Sturluson also gives the bridge a third name, Ásbrú, which means “the bridge of the Aesir”.
Bifrost: Quick Answers
What is Bifrost in Norse mythology? Bifrost is the rainbow bridge between Midgard, the world of humans, and Asgard, the home of the gods. The gods made it, and it has three colors.
Who guards Bifrost in Norse mythology? The god Heimdall. He lives in Himinbjörg at the end of the bridge, and he can see a hundred leagues and hear the grass grow.
What is Heimdall’s sword called? Modern books call it Hofund, from the Old Norse word höfuð, “head”. The Eddas do not give it that name. Snorri only says that a sword can be called “Heimdall’s head”.
How many colors does Bifrost have? Three. Snorri says that the bridge has three colors, and that the red one is burning fire.
Why is Bifrost on fire? The red in the rainbow is burning fire. It keeps the frost giants and mountain giants from crossing into the home of the gods.
What happens to Bifrost at Ragnarok? Bifrost breaks when the sons of Muspell ride over it, led by the fire giant Surtr.
What does the name Bifrost mean? The meaning is uncertain. Bifröst may mean “the trembling mile”. The form Bilröst, used in the Poetic Edda, may mean “the blinking mile”, according to Jackson Crawford.
Sources:
Lee M. Hollander (1962) The Poetic Edda. 15th. edition. Texas, USA: University Research Institute of the University of Texas. ISBN 978-0-292-76499-6 — includes Grímnismál and Fáfnismál.
Jackson Crawford (2018) https://www.youtube.com/watch?v=ILAERgb3V0o&ab_channel=JacksonCrawford
