How do spirits move from world to world?

The refined—or immaterial ether of space is slightly denser than spirit forms, and being relatively lighter, gravity is nearly suspended.

Spirits assume positive action through will and move wherever they will with a rapidity exceeding light. Their flight to a distant star is almost as instantaneous as thought. The more elevated the spirit, the easier this is performed. The lowest minds cannot rise into space at all, and these are around us all the time. These can control physical matters more easily than the higher classes.

The more exalted the spirit becomes, the less he can control the physical things of earth and it becomes impossible to do so directly.

Scenes in the Spirit World or Life in the Spheres