In Norse mythology, the Sun, represented by the goddess Sol, doesn't travel quickly for a specific reason. There's no myth explicitly explaining her speed. Instead, the myth focuses on the dangers she faces during her journey across the sky.

Here's what we know:

* Sol is pursued by the wolf Skoll: Skoll, meaning "Scold" or "Mock," is a monstrous wolf who relentlessly chases the sun across the sky. When he catches up to Sol, it signifies a solar eclipse. This constant chase is a major theme in Sol's journey, creating a sense of urgency and danger.

* The speed is symbolic: Sol's swift journey could be symbolic of the day's quick passage, the constant cycle of sunrise and sunset, or the relentless march of time. It could also reflect the fear and urgency felt by Sol as she flees from Skoll.

The Norse myths don't provide a specific explanation for the Sun's speed. Instead, they emphasize the danger and the fear surrounding her daily journey, which contributes to the drama and symbolism of the myths.