One of the most compelling ideas in all of physics sounds like pure fiction, but it could actually describe our reality: the idea of a multiverse. In the multiverse scenario, what we know as our universe is just one of many universes that independently and simultaneously exist in parallel to our own. Although there is no compelling evidence that points toward either the existence or nonexistence of the multiverse, it provides us with a rich area for exploration, because the predictions of its existence are firmly rooted in theoretical physics phenomena that are definitively known to exist.
If we presume that:
- the hot Big Bang, which gave rise to the observable universe as we know it, was preceded by cosmic inflation
- all of the particles and fields within the universe are fundamentally quantum in nature
Then it follows that the existence of a multiverse is all but inevitable.
The multiverse may be inevitable and parallel universes may be possible, but they do not affect our universe is any measurable or observable way. Beyond the limits of science, all we have is speculation. Until the evidence catches up, no further definitive statements can be made.