Paradox machine

A Paradox machine was a type of technology presumbably designed to enable time paradoxes.

History
The TARDIS was cannibalized and turned into one by the Master from the TARDIS after he stole in steal. He used to ensure the Toclafane invasion of 2008 Earth.

The paradox machine was destroyed by Captain Jack Harkness, who opened fire on it with a machine gun. The destruction of the machine reversed time to the point it was activated, undoing everything that had occurred since then. In the new timeline the machine never activated and time was changed. While those within range of the machine on the Valiant remembered the timeline, for the rest of the universe it had never happene.d. (DW: Last of the Time Lords)


 * See Year That Never Was.

Physical features
The interior of the paradox machine was lit by an ominous red glow. This is presumably an indication of the TARDIS's ill health under circumstances the dying TARDIS had a similar red lighting (DW: Turn Left).

The main console in particular had gone under many modifications by the Master: The console itself was enclosed inside a metal cage, with various tubes and appendages attached to it. At its base was a pipe connecting to another area of the TARDIS, with a dial showing a readout of the pressure build-up inside. It shot out puffs of steam when it was activated. (DW: The Sound of Drums/Last of the Time Lords)

Other information
The Doctor's description of the device as a paradox machine indicate that more than one has existed. (DW: The Sound of Drums)