Gravity globe

A gravity globe used in the core of Krop Tor. (DW: The Impossible Planet)

File:Maze-of-the-dead 02.jpg

A gravity globe used in a Maze of the Dead on Alfava Metraxis. (DW: The Time of Angels)

A gravity globe, or grav globe, was a Human device to provide massive illumination. It could be sent aloft under its own power such that it would "hang" at a certain height and provide downlight over a large area. Grav globes were particularly useful in large caves. (DW: The Impossible Planet, The Satan Pit, The Time of Angels, Flesh and Stone)