The multiverse idea states that there are an arbitrarily large number of Universes like our own, but whether there are any with differences in the laws of physics remains an open question. Image credit: Lee Davy/flickr.

Yes, The Multiverse Is Real, But It Won’t Fix Physics

Surprisingly, the evidence points towards the existence of the unobservable multiverse. But it isn’t the answer you’re looking for.

“We are all agreed that your theory is crazy. The question that divides us is whether it is crazy enough to have a chance of being correct.” Niels Bohr spoke these words to Wolfgang Pauli about the latter’s theory of elementary particles, but it could just as easily apply to many of today’s most controversial modern physics ideas. One that’s gotten a lot of attention recently is that of a Multiverse. In short, it’s the idea that our Universe, and all that’s contained within it, is just one small region of a larger existence that includes many similar, and possibly many different, Universes like our own. On the one hand, if our current theories of physics are true, the Multiverse absolutely must exist. But on the other hand, as Sabine Hossenfelder rightly points out, it’s unlikely to teach us anything useful.

The observable Universe might be 46 billion light years in all directions from our point of view, but there’s certainly more, unobservable Universe, perhaps even an infinite amount, just like ours beyond that. Image credit: Frédéric MICHEL and Andrew Z. Colvin, annotated by E. Siegel.

Why must the Multiverse exist? Quite simply: there must be more Universe than the part that is observable to us. If you look just at the…