Cycle of universal regeneration

The Doctor's universe and all other scales of the multiverse encompassing the Million Spheres underwent a constant gradual cyclical death and rebirth referred to by the denizens of the Doctor's universe as the cycle of universal regeneration. The start and endpoint of each cycle was the Conjunction of the Million Spheres, in which the multiverse underwent the same "form of regeneration" as Time Lords.

The Cosmic Balance of Law and Chaos was central to the functioning of this cycle, with each iteration of the cycle usually tipping more towards one of the two poles. Successive iterations tended to be the reverse of each other, with the universal regeneration reversing matter and anti-matter, Law and Chaos, and "almost everything". The Eleventh Doctor believed that this cycle ensured all life had a sort of "multiversal immortality".

Most people did not remember previous existences, with even Time Lords struggling to do so. The Doctor had undergone several cycles by the time they were the Eleventh Doctor, and admitted to not remembering everything from previous cycles. (PROSE: The Coming of the Terraphiles ^[+]Loading...["The Coming of the Terraphiles (novel)"])

Some accounts indicated that the Doctor's universe underwent a more straightforward cycle of Big Bangs (PROSE: All-Consuming Fire ^[+]Loading...["All-Consuming Fire (novel)"]) or that it was a palimpsest universe, periodically rewritten by time travel and other temporal factors, similarly meaning that the Doctor had experienced an infinite amount of lifetimes, only some of which he could remember. (PROSE: The Infinity Doctors ^[+]Loading...["The Infinity Doctors (novel)"]) On one occasion, the Twelfth Doctor and Rassilon used actual regeneration energy to reboot their universe after its history was perverted by the Cybermen. Most of the universe's denizens did not remember these events, but the Doctor did, and he wondered if Rassilon did also. (COMIC: Supremacy of the Cybermen ^[+]Loading...["Supremacy of the Cybermen (comic story)"])

Behind the scenes

• The cyclical nature of the multiverse is a central aspect of the Michael Moorcock Multiverse. This originated from some of Michael Moorcock's earliest stories, which often touched on the Nietzschean concept of eternal return; this was the origin of the name "Eternal Champion", with the multiverse not being a larger part of that concept until later.
• The Corum series used the term "Cycle of Cycles" for this concept, with it being introduced alongside the "Conjunction of the Million Spheres".
• One of Moorcock's first depictions of the cycle of universal death and rebirth was in the 1964 Elric of Melniboné story Doomed Lord's Passing, which showed Elric's Chaos-based era of ancient Earth history ending in a complete destruction of the universe in order for it to be reborn as the Law-based era of Earth in which recorded human history occurs.
• The Jerry Cornelius 1968 novel The Final Programme compared the sci-fi cycle of universal death and rebirth to the Yuga cycle of Hinduism.