Star Trek: 10 Ways The Romulan Supernova Impacted The Multiverse

If time travel (to the past) is possible in the 'real world,' it will likely require the existence of the multiverse so as to avoid all those pesky paradoxes that would otherwise prevent it. In Star Trek, hopping across universes and across time, whilst definitely doable, is no good for your health. Lieutenant Commander Yor, a "time soldier," found that out the hard way. The Romulan supernova had spread its now ice-cold reach into the fourth millennium.

Though he died in agony or was euthanised by his doctors, Yor did give us the first mention of the Kelvin timeline over in the Prime. A "time soldier," Yor was from a reality "created by the temporal incursion of a Romulan mining ship," Doctor Kovich noted to Doctor Culber (both former-time travellers) in Terra Firma, Part 1. The Betelgeusian in the early TNG-esque uniform had gone from 2379 in Kelvin to some point after the 'Interdimensional Displacement Restriction,' part of the 'Temporal Accords,' had come into force (probably the 31st or 32nd century) in Prime. His molecules didn't want to be there or then.

More recently, and also and most mind-messingly before 2387, another Traveller in time, Wesley 'Sweater Revival' Crusher, gave a relatively off-hand mention to Kelvin, which he called the "Narada Incursion" in The Devourer of All Things, Part I. He'd probably been there too, without the Yor side effects, if his previous statement on the matter of visiting all of the multiple universes was anything to go by.