Bridge to the Stars

From Srafopedia

The Bridge to the Stars (The Golden Compass/Northern Lights, Chapter 23), is the pathway opened up by Lord Asriel between his (and Lyra's) World and a parallel universe.

Asriel knew that to create this "bridge" would require a vast amount of energy. He liberated the energy tied up in the bond between Roger Parslow and his dæmon by effecting the intercision that killed Roger. This is somewhat similar to the process of nuclear fission, where energy is liberated by the breaking of bonds which hold the protons in an atomic nucleus together.

The bridge differs from the windows cut with The Subtle Knife in that it appears to be a kind of additional structure that exists in neither of the two Worlds being connected. Descriptions of the other World suggest that it is "in the sky", so the bridge might also be considered to be a ramp to a different elevation. Windows, on the other hand, have no physical structure of any kind and, being purely multi-dimensional cuts or tears, are unable to deal with altitude variations, as is often apparent when Will is trying to create new ones.