The central power source of the Time Lords’ time travel technology on the planet Gallifrey is a black hole captured and contained within a force field. This captured star provides the practically limitless energy needed for Time Lord TARDISes to traverse time and space. It is often depicted visually as a swirling vortex of energy.
This powerful energy source is crucial to Time Lord civilization and their mastery of temporal mechanics. Control over this energy is essential for operating TARDISes and other advanced technology, giving them unparalleled influence over the universe’s timeline. The containment and exploitation of this energy represents a pinnacle of Time Lord scientific achievement but also presents a significant danger if misused or destabilized. Historical events within the shows narrative demonstrate the catastrophic potential if its containment fails.