Black Holes are holes in space that are created when a star collapses in on itself. It is a place where gravity is so great that nothing, not even light, can escape its pull.
Black holes and the Time Lords
Thought to occur naturally by human astrophysicists, the Doctor stated that the Time Lords invented black holes. (DW: The Satan Pit)
Omega and Rassilon destroyed the star Qqaba (DWM: Star Death) as an energy source powerful enough to enable time travel. Omega, thought dead, survived his journey through this black hole, although he was trapped within it. He was also able to shape matter within it to his will. (DW: The Three Doctors, Arc of Infinity) Rassilon brought back either a black hole or its singularity, no one knows which, to become the Eye of Harmony back on Gallifrey. (DW: The Deadly Assasin)
During the Last Great Time War, the Time Lords used Black Hole Carriers against the Daleks. (DWA: Doctor Who Annual 2006)
The Doctor's TARDIS had the power both to resist the pull of the black hole and also to tug the Walker Expedition's rocket out of the gravitational field of the black hole K37 Gem 5. (DW: The Satan Pit)
Effects on the Universe
Black holes can either behave one of two ways: some holes do, as sometimes speculated, lead to other dimensions and serve as portals; other holes just eat and eat and rip up star systems and anything else. (DW: The Impossible Planet)
Before the universe began, the ancient Disciples of the Light fixed the planet Krop Tor in geostationary orbit around K37 Gem 5. The Doctor, before learning of this, regarded the planet's fixed orbit as scientifically impossible. Both the black hole and the planet served as a prison in which to confine the Beast. (DW: The Impossible Planet/The Satan Pit)
In 2986, the Black Hole of Tartarus presented a hazard to spacecraft. (DW: Terror of the Vervoids)
Artificial black holes
Artificial black holes can be created in place of real ones. In 2006 or later, an experiment in Switzerland (possibly a reference to the large hadron collider) created an artificial black hole, which the robot K-9 then spent a year and a half trying to stabilize in order to protect Earth. (SJA: Invasion of the Bane)
Black holes can also be used as transportation. The Nimons base most of their technology on artificial black holes, especially for long distance transportation. (DW: The Horns of Nimon) The Shalka were able to convert black holes into wormholes for them to travel through. To dispose of waste as well as enemies, the Shalka can change the wormhole back into a black hole. (WC: Scream of the Shalka)
During the Year that Never Happened, the Master created a fleet of Toclafane Rockets, each holding a black hole converter so that he could activate all of them and destroy Earth. The rockets did, however, fade away when time was reversed. (DW: Last of the Time Lords)
Minor references
- An arch-criminal from the planet Nefrin, Brimo, sentenced to remain alive forever in an eternity capsule, found herself inside a black hole when Nefrin's sun collapsed upon itself. Much like Omega, she found herself in a mutable world shaped by her imagination and drained energy from the universe outside it. (DWM: The Time Witch)
- Before his death, Eugene Jones planned on attending a lecture entitled "Black Holes and the Uncertainty Principle" at Aberystwyth University with his friend Gary. Having found a flyer for the lecture in Eugene's room, Gwen Cooper showed up there, hoping to run into Gary there. (TW: Random Shoes).
- There is a black hole in the Casta Pizellus galaxy. (TDA: I am a Dalek)